WorldWideScience

Sample records for biosensors electronic resource

  1. Electronic Biosensors Based on III-Nitride Semiconductors.

    Science.gov (United States)

    Kirste, Ronny; Rohrbaugh, Nathaniel; Bryan, Isaac; Bryan, Zachary; Collazo, Ramon; Ivanisevic, Albena

    2015-01-01

    We review recent advances of AlGaN/GaN high-electron-mobility transistor (HEMT)-based electronic biosensors. We discuss properties and fabrication of III-nitride-based biosensors. Because of their superior biocompatibility and aqueous stability, GaN-based devices are ready to be implemented as next-generation biosensors. We review surface properties, cleaning, and passivation as well as different pathways toward functionalization, and critically analyze III-nitride-based biosensors demonstrated in the literature, including those detecting DNA, bacteria, cancer antibodies, and toxins. We also discuss the high potential of these biosensors for monitoring living cardiac, fibroblast, and nerve cells. Finally, we report on current developments of covalent chemical functionalization of III-nitride devices. Our review concludes with a short outlook on future challenges and projected implementation directions of GaN-based HEMT biosensors.

  2. Wireless implantable electronic platform for chronic fluorescent-based biosensors.

    Science.gov (United States)

    Valdastri, Pietro; Susilo, Ekawahyu; Förster, Thilo; Strohhöfer, Christof; Menciassi, Arianna; Dario, Paolo

    2011-06-01

    The development of a long-term wireless implantable biosensor based on fluorescence intensity measurement poses a number of technical challenges, ranging from biocompatibility to sensor stability over time. One of these challenges is the design of a power efficient and miniaturized electronics, enabling the biosensor to move from bench testing to long term validation, up to its final application in human beings. In this spirit, we present a wireless programmable electronic platform for implantable chronic monitoring of fluorescent-based autonomous biosensors. This system is able to achieve extremely low power operation with bidirectional telemetry, based on the IEEE802.15.4-2003 protocol, thus enabling over three-year battery lifetime and wireless networking of multiple sensors. During the performance of single fluorescent-based sensor measurements, the circuit drives a laser diode, for sensor excitation, and acquires the amplified signals from four different photodetectors. In vitro functionality was preliminarily tested for both glucose and calcium monitoring, simply by changing the analyte-binding protein of the biosensor. Electronics performance was assessed in terms of timing, power consumption, tissue exposure to electromagnetic fields, and in vivo wireless connectivity. The final goal of the presented platform is to be integrated in a complete system for blood glucose level monitoring that may be implanted for at least one year under the skin of diabetic patients. Results reported in this paper may be applied to a wide variety of biosensors based on fluorescence intensity measurement.

  3. Biosensors.

    Science.gov (United States)

    Rechnitz, Garry A.

    1988-01-01

    Describes theory and principles behind biosensors that incorporate biological components as part of a sensor or probe. Projects major applications in medicine and veterinary medicine, biotechnology, food and agriculture, environmental studies, and the military. Surveys current use of biosensors. (ML)

  4. Optical Biosensors: A Revolution Towards Quantum Nanoscale Electronics Device Fabrication

    Directory of Open Access Journals (Sweden)

    D. Dey

    2011-01-01

    Full Text Available The dimension of biomolecules is of few nanometers, so the biomolecular devices ought to be of that range so a better understanding about the performance of the electronic biomolecular devices can be obtained at nanoscale. Development of optical biomolecular device is a new move towards revolution of nano-bioelectronics. Optical biosensor is one of such nano-biomolecular devices that has a potential to pave a new dimension of research and device fabrication in the field of optical and biomedical fields. This paper is a very small report about optical biosensor and its development and importance in various fields.

  5. Sensors: From Biosensors to the Electronic Nose

    OpenAIRE

    García-González, Diego L.; Aparicio López, Ramón

    2002-01-01

    The recent advances in sensor devices have allowed the developing of new applications in many technological fields. This review describes the current state-of-the-art of this sensor technology, placing special emphasis on the food applications. The design, technology and sensing mechanism of each type of sensor are analysed. A description of the main characteristics of the electronic nose and electronic tongue (taste sensors) is also given. Finally, the applications of some statistical pro...

  6. Sensors: From biosensors to the electronic nose

    OpenAIRE

    Aparicio, Ramón; García-González, Diego L.

    2002-01-01

    The recent advances in sensor devices have allowed the developing of new applications in many technological fields. This review describes the current state-of-the-art of this sensor technology, placing special emphasis on the food applications. The design, technology and sensing mechanism of each type of sensor are analysed. A description of the main characteristics of the electronic nose and electronic tongue (taste sensors) is also given. Finally, the applications of some statistical proced...

  7. Sensors: From biosensors to the electronic nose

    Directory of Open Access Journals (Sweden)

    Aparicio, Ramón

    2002-03-01

    Full Text Available The recent advances in sensor devices have allowed the developing of new applications in many technological fields. This review describes the current state-of-the-art of this sensor technology, placing special emphasis on the food applications. The design, technology and sensing mechanism of each type of sensor are analysed. A description of the main characteristics of the electronic nose and electronic tongue (taste sensors is also given. Finally, the applications of some statistical procedures in sensor systems are described briefly.Los recientes avances en los sistemas de sensores han permitido el desarrollo de nuevas aplicaciones en muchos campos tecnológicos. Este artículo de revisión describe el estado actual de esta nueva tecnología, con especial énfasis en las aplicaciones alimentarias. El diseño, la tecnología y el mecanismo sensorial de cada tipo de sensor son analizados en el artículo. También se describen las principales características de la nariz y la lengua electrónica (sensores de sabor. Finalmente, se describe brevemente el uso de algunos procedimientos estadísticos en sistemas de sensores.

  8. Direct electron transfer: an approach for electrochemical biosensors with higher selectivity and sensitivity

    Directory of Open Access Journals (Sweden)

    Freire Renato S.

    2003-01-01

    Full Text Available The most promising approach for the development of electrochemical biosensors is to establish a direct electrical communication between the biomolecules and the electrode surface. This review focuses on advances, directions and strategies in the development of third generation electrochemical biosensors. Subjects covered include a brief description of the fundamentals of the electron transfer phenomenon and amperometric biosensor development (different types and new oriented enzyme immobilization techniques. Special attention is given to different redox enzymes and proteins capable of electrocatalyzing reactions via direct electron transfer. The analytical applications and future trends for third generation biosensors are also presented and discussed.

  9. Electronic Resource Management Systems

    Directory of Open Access Journals (Sweden)

    Mark Ellingsen

    2004-10-01

    Full Text Available Computer applications which deal with electronic resource management (ERM are quite a recent development. They have grown out of the need to manage the burgeoning number of electronic resources particularly electronic journals. Typically, in the early years of e-journal acquisition, library staff provided an easy means of accessing these journals by providing an alphabetical list on a web page. Some went as far as categorising the e-journals by subject and then grouping the journals either on a single web page or by using multiple pages. It didn't take long before it was recognised that it would be more efficient to dynamically generate the pages from a database rather than to continually edit the pages manually. Of course, once the descriptive metadata for an electronic journal was held within a database the next logical step was to provide administrative forms whereby that metadata could be manipulated. This in turn led to demands for incorporating more information and more functionality into the developing application.

  10. A study of the electron transfer and photothermal effect of gold nanorods on a glucose biosensor

    International Nuclear Information System (INIS)

    Liu Huiyu; Yang Liuqing; Ren Xiangling; Tang Fangqiong; Ren Jun; Chen Dong

    2010-01-01

    A new glucose biosensor based on the electron transfer and photothermal effect of gold nanorods (GNRs) is reported here. The biosensor was prepared by immobilizing glucose oxidase (GOx) on a platinum (Pt) electrode by a composite film consisting of GNRs, polyvinyl butyral (PVB) and glutaraldehyde. GNRs were synthesized by a gold seed-mediated cetyltrimethylammonium bromide (CTAB) surfactant-assisted approach. The fabrication, characterization and analytical performance of the glucose biosensor based on GNRs are described in this paper. Moreover, the modulation of the biosensor by the photothermal effect based on the unique surface plasma resonance (SPR) property of GNRs was investigated for the first time. The results show that the current response of a glucose biosensor can significantly increase, induced by the electrical conductivity and photothermal effect of GNRs.

  11. Electronic Resource Management and Design

    Science.gov (United States)

    Abrams, Kimberly R.

    2015-01-01

    We have now reached a tipping point at which electronic resources comprise more than half of academic library budgets. Because of the increasing work associated with the ever-increasing number of e-resources, there is a trend to distribute work throughout the library even in the presence of an electronic resources department. In 2013, the author…

  12. Hybrid functional microfibers for textile electronics and biosensors

    Science.gov (United States)

    Nanda Sahoo, Bichitra; Choi, Byungwoo; Seo, Jungmok; Lee, Taeyoon

    2018-01-01

    Fibers are low-cost substrates that are abundantly used in our daily lives. This review highlights recent advances in the fabrication and application of multifunctional fibers to achieve fibers with unique functions for specific applications ranging from textile electronics to biomedical applications. By incorporating various nanomaterials such as carbon nanomaterials, metallic nanomaterials, and hydrogel-based biomaterials, the functions of fibers can be precisely engineered. This review also highlights the performance of the functional fibers and electronic materials incorporated with textiles and demonstrates their practical application in pressure/tensile sensors, chemical/biosensors, and drug delivery. Textile technologies in which fibers containing biological factors and cells are formed and assembled into constructions with biomimetic properties have attracted substantial attention in the field of tissue engineering. We also discuss the current limitations of functional textile-based devices and their prospects for use in various future applications. Project supported by the Priority Research Centers Program (No. 2012-0006689) through the National Research Foundation (NRF) of Korea funded by the Ministry of Education, Science and Technology (MEST) and the R&D program of MOTIE/KEIT [10064081, Development of fiber-based flexible multimodal pressure sensor and algorithm for gesture/posture-recognizable wearable devices]. We gratefully acknowledge partial support from the National Research Foundation of Korea (No. NRF-2017K2A9A2A06013377, NRF-2017M3A7B4049466) and the Yonsei University Future-leading Research Initiative and Implantable artificial electronic skin for an ubiquitous healthcare system of 2016-12-0050. This work is also supported by KIST Project (Nos. 2E26900, 2E27630). Dr. Seo was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (No. 2016R1A6A3A03006491).

  13. Biosensors

    Indian Academy of Sciences (India)

    and an electronic component to transduce and detect the signal. A variety of .... aliphatic aldehyde as fol- lows: FMNH2 + .... microorganisms by the use of high temperature. ... ISFET. The oxidation of hypoxanthine to uric acid by xanthine.

  14. III - V semiconductor structures for biosensor and molecular electronics applications

    Energy Technology Data Exchange (ETDEWEB)

    Luber, S M

    2007-01-15

    The present work reports on the employment of III-V semiconductor structures to biosensor and molecular electronics applications. In the first part a sensor based on a surface-near two dimensional electron gas for a use in biological environment is studied. Such a two dimensional electron gas inherently forms in a molecular beam epitaxy (MBE) grown, doped aluminum gallium arsenide - gallium arsenide (AlGaAs-GaAs) heterostructure. Due to the intrinsic instability of GaAs in aqueous solutions the device is passivated by deposition of a monolayer of 4'-substituted mercaptobiphenyl molecules. The influence of these molecules which bind to the GaAs via a sulfur group is investigated by Kelvin probe measurements in air. They reveal a dependence of GaAs electron affinity on the intrinsic molecular dipole moment of the mercaptobiphenyls. Furthermore, transient surface photovoltage measurements are presented which demonstrate an additional influence of mercaptobiphenyl chemisorption on surface carrier recombination rates. As a next step, the influence of pH-value and salt concentration upon the sensor device is discussed based on the results obtained from sensor conductance measurements in physiological solutions. A dependence of the device surface potential on both parameters due to surface charging is deduced. Model calculations applying Poisson-Boltzmann theory reveal as possible surface charging mechanisms either the adsorption of OH- ions on the surface, or the dissociation of OH groups in surface oxides. A comparison between simulation settings and physical device properties indicate the OH- adsorption as the most probable mechanism. In the second part of the present study the suitability of MBE grown III-V semiconductor structures for molecular electronics applications is examined. In doing so, a method to fabricate nanometer separated, coplanar, metallic electrodes based on the cleavage of a supporting AlGaAs-GaAs heterostructure is presented. This is followed by a

  15. III - V semiconductor structures for biosensor and molecular electronics applications

    Energy Technology Data Exchange (ETDEWEB)

    Luber, S.M.

    2007-01-15

    The present work reports on the employment of III-V semiconductor structures to biosensor and molecular electronics applications. In the first part a sensor based on a surface-near two dimensional electron gas for a use in biological environment is studied. Such a two dimensional electron gas inherently forms in a molecular beam epitaxy (MBE) grown, doped aluminum gallium arsenide - gallium arsenide (AlGaAs-GaAs) heterostructure. Due to the intrinsic instability of GaAs in aqueous solutions the device is passivated by deposition of a monolayer of 4'-substituted mercaptobiphenyl molecules. The influence of these molecules which bind to the GaAs via a sulfur group is investigated by Kelvin probe measurements in air. They reveal a dependence of GaAs electron affinity on the intrinsic molecular dipole moment of the mercaptobiphenyls. Furthermore, transient surface photovoltage measurements are presented which demonstrate an additional influence of mercaptobiphenyl chemisorption on surface carrier recombination rates. As a next step, the influence of pH-value and salt concentration upon the sensor device is discussed based on the results obtained from sensor conductance measurements in physiological solutions. A dependence of the device surface potential on both parameters due to surface charging is deduced. Model calculations applying Poisson-Boltzmann theory reveal as possible surface charging mechanisms either the adsorption of OH- ions on the surface, or the dissociation of OH groups in surface oxides. A comparison between simulation settings and physical device properties indicate the OH- adsorption as the most probable mechanism. In the second part of the present study the suitability of MBE grown III-V semiconductor structures for molecular electronics applications is examined. In doing so, a method to fabricate nanometer separated, coplanar, metallic electrodes based on the cleavage of a supporting AlGaAs-GaAs heterostructure is presented. This is followed

  16. Graphene Electronic Device Based Biosensors and Chemical Sensors

    Science.gov (United States)

    Jiang, Shan

    Two-dimensional layered materials, such as graphene and MoS2, are emerging as an exciting material system for a new generation of atomically thin electronic devices. With their ultrahigh surface to volume ratio and excellent electrical properties, 2D-layered materials hold the promise for the construction of a generation of chemical and biological sensors with unprecedented sensitivity. In my PhD thesis, I mainly focus on graphene based electronic biosensors and chemical sensors. In the first part of my thesis, I demonstrated the fabrication of graphene nanomesh (GNM), which is a graphene thin film with a periodic array of holes punctuated in it. The periodic holes introduce long periphery active edges that provide a high density of functional groups (e.g. carboxylic groups) to allow for covalent grafting of specific receptor molecules for chemical and biosensor applications. After covalently functionalizing the GNM with glucose oxidase, I managed to make a novel electronic sensor which can detect glucose as well as pH change. In the following part of my thesis I demonstrate the fabrication of graphene-hemin conjugate for nitric oxide detection. The non-covalent functionalization through pi-pi stacking interaction allows reliable immobilization of hemin molecules on graphene without damaging the graphene lattice to ensure the highly sensitive and specific detection of nitric oxide. The graphene-hemin nitric oxide sensor is capable of real-time monitoring of nitric oxide concentrations, which is of central importance for probing the diverse roles of nitric oxide in neurotransmission, cardiovascular systems, and immune responses. Our studies demonstrate that the graphene-hemin sensors can respond rapidly to nitric oxide in physiological environments with sub-nanomolar sensitivity. Furthermore, in vitro studies show that the graphene-hemin sensors can be used for the detection of nitric oxide released from macrophage cells and endothelial cells, demonstrating their

  17. Electronically type-sorted carbon nanotube-based electrochemical biosensors with glucose oxidase and dehydrogenase.

    Science.gov (United States)

    Muguruma, Hitoshi; Hoshino, Tatsuya; Nowaki, Kohei

    2015-01-14

    An electrochemical enzyme biosensor with electronically type-sorted (metallic and semiconducting) single-walled carbon nanotubes (SWNTs) for use in aqueous media is presented. This research investigates how the electronic types of SWNTs influence the amperometric response of enzyme biosensors. To conduct a clear evaluation, a simple layer-by-layer process based on a plasma-polymerized nano thin film (PPF) was adopted because a PPF is an inactive matrix that can form a well-defined nanostructure composed of SWNTs and enzyme. For a biosensor with the glucose oxidase (GOx) enzyme in the presence of oxygen, the response of a metallic SWNT-GOx electrode was 2 times larger than that of a semiconducting SWNT-GOx electrode. In contrast, in the absence of oxygen, the response of the semiconducting SWNT-GOx electrode was retained, whereas that of the metallic SWNT-GOx electrode was significantly reduced. This indicates that direct electron transfer occurred with the semiconducting SWNT-GOx electrode, whereas the metallic SWNT-GOx electrode was dominated by a hydrogen peroxide pathway caused by an enzymatic reaction. For a biosensor with the glucose dehydrogenase (GDH; oxygen-independent catalysis) enzyme, the response of the semiconducting SWNT-GDH electrode was 4 times larger than that of the metallic SWNT-GDH electrode. Electrochemical impedance spectroscopy was used to show that the semiconducting SWNT network has less resistance for electron transfer than the metallic SWNT network. Therefore, it was concluded that semiconducting SWNTs are more suitable than metallic SWNTs for electrochemical enzyme biosensors in terms of direct electron transfer as a detection mechanism. This study makes a valuable contribution toward the development of electrochemical biosensors that employ sorted SWNTs and various enzymes.

  18. Direct Electron Transfer of Dehydrogenases for Development of 3rd Generation Biosensors and Enzymatic Fuel Cells

    Directory of Open Access Journals (Sweden)

    Paolo Bollella

    2018-04-01

    Full Text Available Dehydrogenase based bioelectrocatalysis has been increasingly exploited in recent years in order to develop new bioelectrochemical devices, such as biosensors and biofuel cells, with improved performances. In some cases, dehydrogeases are able to directly exchange electrons with an appropriately designed electrode surface, without the need for an added redox mediator, allowing bioelectrocatalysis based on a direct electron transfer process. In this review we briefly describe the electron transfer mechanism of dehydrogenase enzymes and some of the characteristics required for bioelectrocatalysis reactions via a direct electron transfer mechanism. Special attention is given to cellobiose dehydrogenase and fructose dehydrogenase, which showed efficient direct electron transfer reactions. An overview of the most recent biosensors and biofuel cells based on the two dehydrogenases will be presented. The various strategies to prepare modified electrodes in order to improve the electron transfer properties of the device will be carefully investigated and all analytical parameters will be presented, discussed and compared.

  19. A lactate electrochemical biosensor with a titanate nanotube as direct electron transfer promoter

    International Nuclear Information System (INIS)

    Yang Mingli; Wang Jin; Li Huaqing; Wu Nianqiang Nick; Zheng Jianguo

    2008-01-01

    Hydrogen titanate (H 2 Ti 3 O 7 ) nanotubes (TNTs) have been synthesized by a one-step hydrothermal processing. Lactate oxidase (LOx) enzyme has been immobilized on the three-dimensional porous TNT network to make an electrochemical biosensor for lactate detection. Cyclic voltammetry and amperometry tests reveal that the LOx enzyme, which is supported on TNTs, maintains their substrate-specific catalytic activity. The nanotubes offer the pathway for direct electron transfer between the electrode surface and the active redox centers of LOx, which enables the biosensor to operate at a low working potential and to avoid the influence of the presence of O 2 on the amperometric current response. The biosensor exhibits a sensitivity of 0.24 μA cm -2 mM -1 , a 90% response time of 5 s, and a linear response in the range from 0.5 to 14 mM and the redox center of enzyme obviates the need of redox mediators for electrochemical enzymatic sensors, which is attractive for the development of reagentless biosensors

  20. A lactate electrochemical biosensor with a titanate nanotube as direct electron transfer promoter

    Science.gov (United States)

    Yang, Mingli; Wang, Jin; Li, Huaqing; Zheng, Jian-Guo; Wu, Nianqiang Nick

    2008-02-01

    Hydrogen titanate (H2Ti3O7) nanotubes (TNTs) have been synthesized by a one-step hydrothermal processing. Lactate oxidase (LOx) enzyme has been immobilized on the three-dimensional porous TNT network to make an electrochemical biosensor for lactate detection. Cyclic voltammetry and amperometry tests reveal that the LOx enzyme, which is supported on TNTs, maintains their substrate-specific catalytic activity. The nanotubes offer the pathway for direct electron transfer between the electrode surface and the active redox centers of LOx, which enables the biosensor to operate at a low working potential and to avoid the influence of the presence of O2 on the amperometric current response. The biosensor exhibits a sensitivity of 0.24 µA cm-2 mM-1, a 90% response time of 5 s, and a linear response in the range from 0.5 to 14 mM and the redox center of enzyme obviates the need of redox mediators for electrochemical enzymatic sensors, which is attractive for the development of reagentless biosensors.

  1. Ultra-low current biosensor output detection using portable electronic reader

    Science.gov (United States)

    Yahaya, N. A. N.; Rajapaksha, R. D. A. A.; Uda, M. N. Afnan; Hashim, U.

    2017-09-01

    Generally, the electrical biosensor usually shows extremely low current signal output around pico ampere to microampere range. In this research, electronic reader with amplifier has been demonstrated to detect ultra low current via the biosensor. The operational amplifier Burr-Brown OPA 128 and Arduino Uno board were used to construct the portable electronic reader. There are two cascaded inverting amplifier were used to detect ultra low current through the biosensor from pico amperes (pA) to nano amperes ranges (nA). A small known input current was form by applying variable voltage between 0.1V to 5.0V across a 5GΩ high resistor to check the amplifier circuit. The amplifier operation was measured with the high impedance current source and has been compared with the theoretical measurement. The Arduino Uno was used to convert the analog signal to digital signal and process the data to display on reader screen. In this project, Proteus software was used to design and test the circuit. Then it was implemented together with Arduino Uno board. Arduino board was programmed using C programming language to make whole circuit communicate each order. The current was measured then it shows a small difference values compared to theoretical values, which is approximately 14pA.

  2. Highly sensitive and selective cholesterol biosensor based on direct electron transfer of hemoglobin.

    Science.gov (United States)

    Zhao, Changzhi; Wan, Li; Jiang, Li; Wang, Qin; Jiao, Kui

    2008-12-01

    A cholesterol biosensor based on direct electron transfer of a hemoglobin-encapsulated chitosan-modified glassy carbon electrode has been developed for highly sensitive and selective analysis of serum samples. Modified by films containing hemoglobin and cholesterol oxidase, the electrode was prepared by encapsulation of enzyme in chitosan matrix. The hydrogen peroxide produced by the catalytic oxidation of cholesterol by cholesterol oxidase was reduced electrocatalytically by immobilized hemoglobin and used to obtain a sensitive amperometric response to cholesterol. The linear response of cholesterol concentrations ranged from 1.00 x 10(-5) to 6.00 x 10(-4) mol/L, with a correlation coefficient of 0.9969 and estimated detection limit of cholesterol of 9.5 micromol/L at a signal/noise ratio of 3. The cholesterol biosensor can efficiently exclude interference by the commonly coexisting ascorbic acid, uric acid, dopamine, and epinephrine. The sensitivity to the change in the concentration of cholesterol as the slope of the calibration curve was 0.596 A/M. The relative standard deviation was under 4.0% (n=5) for the determination of real samples. The biosensor is satisfactory in the determination of human serum samples.

  3. Managing electronic resources a LITA guide

    CERN Document Server

    Weir, Ryan O

    2012-01-01

    Informative, useful, current, Managing Electronic Resources: A LITA Guide shows how to successfully manage time, resources, and relationships with vendors and staff to ensure personal, professional, and institutional success.

  4. A biosensor for hydrogen peroxide detection based on electronic properties of carbon nanotubes

    Science.gov (United States)

    Majidi, Roya

    2013-01-01

    Density functional theory has been used to study the effect of hydrogen peroxide on the electronic properties of single walled carbon nanotubes. The metallic and semiconducting carbon nanotubes have been considered in the presence of different number of hydrogen peroxide. The results indicate that hydrogen peroxide has no significant effect on the metallic nanotube and these nanotubes remain to be metallic. In contrast, the electronic properties of the semiconducting nanotubes are so sensitive to hydrogen peroxide. The energy band gap of these nanotubes is decreased by increasing the number of hydrogen peroxide. The electronic sensivity of the carbon nanotubes to hydrogen peroxide opens new insights into developing biosensors based on the single walled carbon nanotubes.

  5. Electronic Resources Management Project Presentation 2012

    KAUST Repository

    Ramli, Rindra M.

    2012-11-05

    This presentation describes the electronic resources management project undertaken by the KAUST library. The objectives of this project is to migrate information from MS Sharepoint to Millennium ERM module. One of the advantages of this migration is to consolidate all electronic resources into a single and centralized location. This would allow for better information sharing among library staff.

  6. Implementing CORAL: An Electronic Resource Management System

    Science.gov (United States)

    Whitfield, Sharon

    2011-01-01

    A 2010 electronic resource management survey conducted by Maria Collins of North Carolina State University and Jill E. Grogg of University of Alabama Libraries found that the top six electronic resources management priorities included workflow management, communications management, license management, statistics management, administrative…

  7. Biodegradable elastomers and silicon nanomembranes/nanoribbons for stretchable, transient electronics, and biosensors.

    Science.gov (United States)

    Hwang, Suk-Won; Lee, Chi Hwan; Cheng, Huanyu; Jeong, Jae-Woong; Kang, Seung-Kyun; Kim, Jae-Hwan; Shin, Jiho; Yang, Jian; Liu, Zhuangjian; Ameer, Guillermo A; Huang, Yonggang; Rogers, John A

    2015-05-13

    Transient electronics represents an emerging class of technology that exploits materials and/or device constructs that are capable of physically disappearing or disintegrating in a controlled manner at programmed rates or times. Inorganic semiconductor nanomaterials such as silicon nanomembranes/nanoribbons provide attractive choices for active elements in transistors, diodes and other essential components of overall systems that dissolve completely by hydrolysis in biofluids or groundwater. We describe here materials, mechanics, and design layouts to achieve this type of technology in stretchable configurations with biodegradable elastomers for substrate/encapsulation layers. Experimental and theoretical results illuminate the mechanical properties under large strain deformation. Circuit characterization of complementary metal-oxide-semiconductor inverters and individual transistors under various levels of applied loads validates the design strategies. Examples of biosensors demonstrate possibilities for stretchable, transient devices in biomedical applications.

  8. Electronic Resources Management System: Recommendation Report 2017

    KAUST Repository

    Ramli, Rindra M.

    2017-01-01

    This recommendation report provides an overview of the selection process for the new Electronic Resources Management System. The library has decided to move away from Innovative Interfaces Millennium ERM module. The library reviewed 3 system

  9. Electronic Resources Management Project Presentation 2012

    KAUST Repository

    Ramli, Rindra M.

    2012-01-01

    This presentation describes the electronic resources management project undertaken by the KAUST library. The objectives of this project is to migrate information from MS Sharepoint to Millennium ERM module. One of the advantages of this migration

  10. PRINCIPLES OF CONTENT FORMATION EDUCATIONAL ELECTRONIC RESOURCE

    Directory of Open Access Journals (Sweden)

    О Ю Заславская

    2017-12-01

    Full Text Available The article considers modern possibilities of information and communication technologies for the design of electronic educational resources. The conceptual basis of the open educational multimedia system is based on the modular architecture of the electronic educational resource. The content of the electronic training module can be implemented in several versions of the modules: obtaining information, practical exercises, control. The regularities in the teaching process in modern pedagogical theory are considered: general and specific, and the principles for the formation of the content of instruction at different levels are defined, based on the formulated regularities. On the basis of the analysis, the principles of the formation of the electronic educational resource are determined, taking into account the general and didactic patterns of teaching.As principles of the formation of educational material for obtaining information for the electronic educational resource, the article considers: the principle of methodological orientation, the principle of general scientific orientation, the principle of systemic nature, the principle of fundamentalization, the principle of accounting intersubject communications, the principle of minimization. The principles of the formation of the electronic training module of practical studies in the article include: the principle of systematic and dose based consistency, the principle of rational use of study time, the principle of accessibility. The principles of the formation of the module for monitoring the electronic educational resource can be: the principle of the operationalization of goals, the principle of unified identification diagnosis.

  11. Electronic Resources Management System: Recommendation Report 2017

    KAUST Repository

    Ramli, Rindra M.

    2017-05-01

    This recommendation report provides an overview of the selection process for the new Electronic Resources Management System. The library has decided to move away from Innovative Interfaces Millennium ERM module. The library reviewed 3 system as potential replacements namely: Proquest 360 Resource Manager, Ex Libris Alma and Open Source CORAL ERMS. After comparing and trialling the systems, it was decided to go for Proquest 360 Resource Manager.

  12. CHALLENGES OF ELECTRONIC INFORMATION RESOURCES IN ...

    African Journals Online (AJOL)

    This paper discusses the role of policy for proper and efficient library services in the electronic era. It points out some of the possible dangers of embarking in electronic resources without a proper focus at hand. Thus, it calls for today's librarians and policy makers to brainstorm and come up with working policies suitable to ...

  13. ENHANCING DIRECT ELECTRON TRANSFER OF GLUCOSE OXIDASE USING A GOLD NANOPARTICLE |TITANATE NANOTUBE NANOCOMPOSITE ON A BIOSENSOR

    International Nuclear Information System (INIS)

    Zhao, Ruoxia; Liu, Xiaoqiang; Zhang, Jiamei; Zhu, Jie; Wong, Danny K.Y.

    2015-01-01

    ABSTRACT: In this paper, we have developed a gold nanoparticle (GNP) decorated titanate nanotubes (TNT) nanocomposite that aids in the direct electron transfer of a large enzyme, such as glucose oxidase (GOD), in which the electroactive site of flavin adenine dinucleotide is deeply buried within the enzyme. The ionic liquid, brominated 1-decyl-3-methyl imidazole, was used to immobilise the nanocomposite and the enzyme on a glassy carbon electrode to further aid in the electron transfer between GOD and the electrode surface. Nafion was also added to anchor the biosensor scaffold. Initially, the tubiform geometry of titanate nanomaterials and the GNP-TNT nanocomposite was confirmed by microscopic and spectroscopic techniques before glucose oxidase was entrapped in the nanocomposite. Based on voltammetric results, this biosensor showed a strong electrocatalytic capability towards glucose (with a heterogeneous electron transfer rate constant of 7.1 s −1 at 180 mV s −1 ) and the calibration for glucose exhibited a high sensitivity (5.1 μA mM −1 ) and a wide linear range (0.01–1.2 mM). These results demonstrated superior analytical performance of our biosensor over others fabricated using bulkier TiO 2 nanoparticles or nanobundles, which could be attributed to a high degree of biocompatibility to glucose oxidase and electrical conductivity of the nanocomposite

  14. Library training to promote electronic resource usage

    DEFF Research Database (Denmark)

    Frandsen, Tove Faber; Tibyampansha, Dativa; Ibrahim, Glory

    2017-01-01

    Purpose: Increasing the usage of electronic resources is an issue of concern for many libraries all over the world. Several studies stress the importance of information literacy and instruction in order to increase the usage. Design/methodology/approach: The present article presents the results...

  15. A novel nitrite biosensor based on the direct electron transfer hemoglobin immobilized in the WO3 nanowires with high length–diameter ratio

    International Nuclear Information System (INIS)

    Liu, Hui; Duan, Congyue; Yang, Chenhui; Chen, Xianjin; Shen, Wanqiu; Zhu, Zhenfeng

    2015-01-01

    WO 3 nanowires (WO 3 NWs) with high length–diameter ratio have been synthesized through a simple synthetic route without any additive and then used to immobilize hemoglobin (Hb) to fabricate a mediator-free biosensor. The morphology and structure of WO 3 NWs were characterized by scanning electron microscopy, transmission electronic microscopy and X-ray diffraction. Spectroscopic and electrochemical results revealed that WO 3 NWs are an excellent immobilization matrix with biocompatibility for redox protein, affording good protein bioactivity and stability. Meanwhile, due to unique morphology and property of the WO 3 nanowires, the direct electron transfer of Hb is facilitated and the prepared biosensors displayed good performance for the detection of nitrite with a wide linear range of 1 to 4200 μM, as well as an extremely low detection limit of 0.28 μM. The WO 3 nanowires with high length–diameter ratio could be a promising matrix for the fabrication of mediator-free biosensors, and may find wide potential applications in environmental analysis and biomedical detection. - Highlights: • The WO 3 NWs with high length–diameter ratio have been synthesized. • The WO 3 NWs were used to immobilize Hb to fabricate a mediator-free biosensor. • The biosensor displays a wide linear range of 1–4200 μM for nitrite. • The biosensor exhibits an extremely low detection limit of 0.28 μM for nitrite

  16. Electronic resource management systems a workflow approach

    CERN Document Server

    Anderson, Elsa K

    2014-01-01

    To get to the bottom of a successful approach to Electronic Resource Management (ERM), Anderson interviewed staff at 11 institutions about their ERM implementations. Among her conclusions, presented in this issue of Library Technology Reports, is that grasping the intricacies of your workflow-analyzing each step to reveal the gaps and problems-at the beginning is crucial to selecting and implementing an ERM. Whether the system will be used to fill a gap, aggregate critical data, or replace a tedious manual process, the best solution for your library depends on factors such as your current soft

  17. use of electronic resources by graduate students of the department

    African Journals Online (AJOL)

    respondent's access electronic resources from the internet via Cybercafé .There is a high ... KEY WORDS: Use, Electronic Resources, Graduate Students, Cybercafé. INTRODUCTION ... Faculty of Education, University of Uyo, Uyo. Olu Olat ...

  18. Biosensors and environmental health

    National Research Council Canada - National Science Library

    Preedy, Victor R; Patel, Vinood B

    2012-01-01

    ..., bacterial biosensors, antibody-based biosensors, enzymatic, amperometric and electrochemical aspects, quorum sensing, DNA-biosensors, cantilever biosensors, bioluminescence and other methods and applications...

  19. Optical biosensors.

    Science.gov (United States)

    Damborský, Pavel; Švitel, Juraj; Katrlík, Jaroslav

    2016-06-30

    Optical biosensors represent the most common type of biosensor. Here we provide a brief classification, a description of underlying principles of operation and their bioanalytical applications. The main focus is placed on the most widely used optical biosensors which are surface plasmon resonance (SPR)-based biosensors including SPR imaging and localized SPR. In addition, other optical biosensor systems are described, such as evanescent wave fluorescence and bioluminescent optical fibre biosensors, as well as interferometric, ellipsometric and reflectometric interference spectroscopy and surface-enhanced Raman scattering biosensors. The optical biosensors discussed here allow the sensitive and selective detection of a wide range of analytes including viruses, toxins, drugs, antibodies, tumour biomarkers and tumour cells. © 2016 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  20. A novel nitrite biosensor based on the direct electron transfer hemoglobin immobilized in the WO{sub 3} nanowires with high length–diameter ratio

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hui, E-mail: liuhui@sust.edu.cn; Duan, Congyue; Yang, Chenhui; Chen, Xianjin; Shen, Wanqiu; Zhu, Zhenfeng

    2015-08-01

    WO{sub 3} nanowires (WO{sub 3}NWs) with high length–diameter ratio have been synthesized through a simple synthetic route without any additive and then used to immobilize hemoglobin (Hb) to fabricate a mediator-free biosensor. The morphology and structure of WO{sub 3}NWs were characterized by scanning electron microscopy, transmission electronic microscopy and X-ray diffraction. Spectroscopic and electrochemical results revealed that WO{sub 3}NWs are an excellent immobilization matrix with biocompatibility for redox protein, affording good protein bioactivity and stability. Meanwhile, due to unique morphology and property of the WO{sub 3} nanowires, the direct electron transfer of Hb is facilitated and the prepared biosensors displayed good performance for the detection of nitrite with a wide linear range of 1 to 4200 μM, as well as an extremely low detection limit of 0.28 μM. The WO{sub 3} nanowires with high length–diameter ratio could be a promising matrix for the fabrication of mediator-free biosensors, and may find wide potential applications in environmental analysis and biomedical detection. - Highlights: • The WO{sub 3}NWs with high length–diameter ratio have been synthesized. • The WO{sub 3}NWs were used to immobilize Hb to fabricate a mediator-free biosensor. • The biosensor displays a wide linear range of 1–4200 μM for nitrite. • The biosensor exhibits an extremely low detection limit of 0.28 μM for nitrite.

  1. AlGaN/GaN High Electron Mobility Transistor-Based Biosensor for the Detection of C-Reactive Protein.

    Science.gov (United States)

    Lee, Hee Ho; Bae, Myunghan; Jo, Sung-Hyun; Shin, Jang-Kyoo; Son, Dong Hyeok; Won, Chul-Ho; Jeong, Hyun-Min; Lee, Jung-Hee; Kang, Shin-Won

    2015-07-28

    In this paper, we propose an AlGaN/GaN high electron mobility transistor (HEMT)-based biosensor for the detection of C-reactive protein (CRP) using a null-balancing circuit. A null-balancing circuit was used to measure the output voltage of the sensor directly. The output voltage of the proposed biosensor was varied by antigen-antibody interactions on the gate surface due to CRP charges. The AlGaN/GaN HFET-based biosensor with null-balancing circuit applied shows that CRP can be detected in a wide range of concentrations, varying from 10 ng/mL to 1000 ng/mL. X-ray photoelectron spectroscopy was carried out to verify the immobilization of self-assembled monolayer with Au on the gated region.

  2. AlGaN/GaN High Electron Mobility Transistor-Based Biosensor for the Detection of C-Reactive Protein

    Directory of Open Access Journals (Sweden)

    Hee Ho Lee

    2015-07-01

    Full Text Available In this paper, we propose an AlGaN/GaN high electron mobility transistor (HEMT-based biosensor for the detection of C-reactive protein (CRP using a null-balancing circuit. A null-balancing circuit was used to measure the output voltage of the sensor directly. The output voltage of the proposed biosensor was varied by antigen-antibody interactions on the gate surface due to CRP charges. The AlGaN/GaN HFET-based biosensor with null-balancing circuit applied shows that CRP can be detected in a wide range of concentrations, varying from 10 ng/mL to 1000 ng/mL. X-ray photoelectron spectroscopy was carried out to verify the immobilization of self-assembled monolayer with Au on the gated region.

  3. Use of Electronic Resources in a Private University in Nigeria ...

    African Journals Online (AJOL)

    The study examined awareness and constraints in the use of electronic resources by lecturers and students of Ajayi Crowther University, Oyo, Nigeria. It aimed at justifying the resources expended in the provision of electronic resources in terms of awareness, patronage and factors that may be affecting awareness and use ...

  4. Gender Analysis Of Electronic Information Resource Use: The Case ...

    African Journals Online (AJOL)

    Based on the findings the study concluded that access and use of electronic information resources creates a “social digital divide” along gender lines. The study ... Finally, the library needs to change its marketing strategies on the availability of electronic information resources to increase awareness of these resources.

  5. Electronic Resource Management System. Vernetzung von Lizenzinformationen

    Directory of Open Access Journals (Sweden)

    Michaela Selbach

    2014-12-01

    Full Text Available In den letzten zehn Jahren spielen elektronische Ressourcen im Bereich der Erwerbung eine zunehmend wichtige Rolle: Eindeutig lässt sich hier ein Wandel in den Bibliotheken (fort vom reinen Printbestand zu immer größeren E-Only-Beständen feststellen. Die stetig wachsende Menge an E-Ressourcen und deren Heterogenität stellt Bibliotheken vor die Herausforderung, die E-Ressourcen effizient zu verwalten. Nicht nur Bibliotheken, sondern auch verhandlungsführende Institutionen von Konsortial- und Allianzlizenzen benötigen ein geeignetes Instrument zur Verwaltung von Lizenzinformationen, welches den komplexen Anforderungen moderner E-Ressourcen gerecht wird. Die Deutsche Forschungsgemeinschaft (DFG unterstützt ein Projekt des Hochschulbibliothekszentrums des Landes Nordrhein-Westfalen (hbz, der Universitätsbibliothek Freiburg, der Verbundzentrale des Gemeinsamen Bibliotheksverbundes (GBV und der Universitätsbibliothek Frankfurt, in dem ein bundesweit verfügbares Electronic Ressource Managementsystem (ERMS aufgebaut werden soll. Ein solches ERMS soll auf Basis einer zentralen Knowledge Base eine einheitliche Nutzung von Daten zur Lizenzverwaltung elektronischer Ressourcen auf lokaler, regionaler und nationaler Ebene ermöglichen. Statistische Auswertungen, Rechteverwaltung für alle angeschlossenen Bibliotheken, kooperative Datenpflege sowie ein über standardisierte Schnittstellen geführter Datenaustausch stehen bei der Erarbeitung der Anforderungen ebenso im Fokus wie die Entwicklung eines Daten- und Funktionsmodells. In the last few years the importance of electronic resources in library acquisitions has increased significantly. There has been a shift from mere print holdings to both e- and print combinations and even e-only subscriptions. This shift poses a double challenge for libraries: On the one hand they have to provide their e-resource collections to library users in an appealing way, on the other hand they have to manage these

  6. Electronic human resource management: Enhancing or entrancing?

    Directory of Open Access Journals (Sweden)

    Paul Poisat

    2017-07-01

    Full Text Available Orientation: This article provides an investigation into the current level of development of the body of knowledge related to electronic human resource management (e-HRM by means of a qualitative content analysis. Several aspects of e-HRM, namely definitions of e-HRM, the theoretical perspectives around e-HRM, the role of e-HRM, the various types of e-HRM and the requirements for successful e-HRM, are examined. Research purpose: The purpose of the article was to determine the status of e-HRM and examine the studies that report on the link between e-HRM and organisational productivity. Motivation for the study: e-HRM has the capacity to improve organisational efficiency and leverage the role of human resources (HR as a strategic business partner. Main findings: The notion that the implementation of e-HRM will lead to improved organisational productivity is commonly assumed; however, empirical evidence in this regard was found to be limited. Practical/managerial implications: From the results of this investigation it is evident that more research is required to gain a greater understanding of the influence of e-HRM on organisational productivity, as well as to develop measures for assessing this influence. Contribution: This article proposes additional areas to research and measure when investigating the effectiveness of e-HRM. It provides a different lens from which to view e-HRM assessment whilst keeping it within recognised HR measurement parameters (the HR value chain. In addition, it not only provides areas for measuring e-HRM’s influence but also provides important clues as to how the measurements may be approached.

  7. Utilization of electronic information resources by academic staff at ...

    African Journals Online (AJOL)

    The study investigated the utilization of Electronic Information resources by the academic staff of Makerere University in Uganda. It examined the academic staff awareness of the resources available, the types of resources provided by the Makerere University Library, the factors affecting resource utilization. The study was ...

  8. A glucose biosensor based on direct electron transfer of glucose oxidase immobilized onto glassy carbon electrode modified with nitrophenyl diazonium salt

    International Nuclear Information System (INIS)

    Nasri, Zahra; Shams, Esmaeil

    2013-01-01

    Graphical abstract: - Abstract: This study reports a novel, simple and fast approach for construction of a highly stable glucose biosensor based on the immobilization of glucose oxidase (GOx) onto a glassy carbon electrode (GCE) electrografted with 4-aminophenyl (AP) by diazonium chemistry. Aminophenyl was used as cross-linker for covalent attachment of glucose oxidase to the electrode surface. Cyclic voltammograms of the GOx-modified GCE in phosphate buffer solution exhibited a pair of well-defined redox peaks, attesting the direct electron transfer (DET) of GOx with the underlying electrode. The proposed biosensor could be used to detect glucose based on the consumption of O 2 with the oxidation of glucose catalyzed by GOx and exhibited a wide linear range of glucose from 0.05 mM to 4.5 mM and low detection limit of 10 μM. The surface coverage of active GOx, heterogeneous electron transfer rate constant (k s ) and Michaelis–Menten constant (K M ) of immobilized GOx were 1.23 × 10 −12 mol cm −2 , 4.25 s −1 and 2.95 mM, respectively. The great stability of this biosensor, technically simple and possibility of preparation at short period of time make this method suitable for fabrication of low-cost glucose biosensors

  9. Biosensor for metal analysis and speciation

    Science.gov (United States)

    Aiken, Abigail M.; Peyton, Brent M.; Apel, William A.; Petersen, James N.

    2007-01-30

    A biosensor for metal analysis and speciation is disclosed. The biosensor comprises an electron carrier immobilized to a surface of an electrode and a layer of an immobilized enzyme adjacent to the electrode. The immobilized enzyme comprises an enzyme having biological activity inhibited by a metal to be detected by the biosensor.

  10. Users satisfaction with electronic information resources and services ...

    African Journals Online (AJOL)

    This study investigated users satisfaction on the use of electronic information resources and services in MTN Net libraries in ABU & UNIBEN. Two objectives and one null hypotheses were formulated and tested with respect to the users' satisfaction on electronic information resources and services in MTN Net libraries in ...

  11. The Role of the Acquisitions Librarian in Electronic Resources Management

    Science.gov (United States)

    Pomerantz, Sarah B.

    2010-01-01

    With the ongoing shift to electronic formats for library resources, acquisitions librarians, like the rest of the profession, must adapt to the rapidly changing landscape of electronic resources by keeping up with trends and mastering new skills related to digital publishing, technology, and licensing. The author sought to know what roles…

  12. Rapid localized deactivation of self-assembled monolayers by propagation-controlled laser-induced plasma and its application to self-patterning of electronics and biosensors

    Science.gov (United States)

    Kim, Jongsu; Kwon, Seung-Gab; Back, Seunghyun; Kang, Bongchul

    2018-03-01

    We present a novel laser-induced surface treatment process to rapidly control the spatial wettabilities of various functional solutions with submicron to micron resolutions. Ultrathin hydrophobic self-assembled monolayers (SAMs) that little absorb typical laser lights due to short penetration depth were selectively deactivated by instantaneous interaction with laser-induced metallic plasmas. The spatial region of the deactivated SAM, which corresponds to process resolution, is adjustable by controlling the spatial propagation of the plasma. This method leads to the parallel formation of hydrophilic functional solutions on glass substrates with a minimum resolution on the submicron scale. To show its feasibility in device engineering fields, this method was applied to the cost-effective fabrication of electronics and biosensors. Rapid self-patterning of electronic and biological functional solutions (silver nanoparticle solution and streptavidin protein solution) was successfully realized by selective deactivation of two different SAMs (tridecafluoro-1,1,2,2-tetrahydrooctyltrichlorosilane (FOTS) for electronics and the hetero-hybrid SAM (octadecyltrichlorosilane (OTS)/2-[methoxy(polyethyleneoxy)propyl] trichlorosilane (PEG)) for biosensors). As a result, this method can be exploited for the rapid and low-cost fabrication of various thin film devices such as electronics, biosensors, energy, displays, and photonics.

  13. Selection and Evaluation of Electronic Resources

    Directory of Open Access Journals (Sweden)

    Doğan Atılgan

    2013-11-01

    Full Text Available Publication boom and issues related to controlling and accession of printed sources have created some problems after World War II. Consequently, publishing industry has encountered the problem of finding possible solution for emerged situation. Industry of electronic publishing has started to improve with the rapid increase of the price of printed sources as well as the problem of publication boom. The first effects of electronic publishing were appeared on the academic and scholarly publications then electronic publishing became a crucial part of all types of publications. As a result of these developments, collection developments and service policies of information centers were also significantly changed. In this article, after a general introduction about selection and evaluation processes of electronic publications, the subscribed databases by a state and a privately owned university in Turkey and their usage were examined.

  14. Improving Electronic Resources through Holistic Budgeting

    Science.gov (United States)

    Kusik, James P.; Vargas, Mark A.

    2009-01-01

    To establish a more direct link between its collections and the educational goals of Saint Xavier University, the Byrne Memorial Library has adopted a "holistic" approach to collection development. This article examines how traditional budget practices influenced the library's selection of resources and describes how holistic collection…

  15. Page 170 Use of Electronic Resources by Undergraduates in Two ...

    African Journals Online (AJOL)

    undergraduate students use electronic resources such as NUC virtual library, HINARI, ... web pages articles from magazines, encyclopedias, pamphlets and other .... of Nigerian university libraries have Internet connectivity, some of the system.

  16. Layered composites of PEDOT/PSS/nanoparticles and PEDOT/PSS/phthalocyanines as electron mediators for sensors and biosensors

    Directory of Open Access Journals (Sweden)

    Celia García-Hernández

    2016-12-01

    Full Text Available The sensing properties of electrodes chemically modified with PEDOT/PSS towards catechol and hydroquinone sensing have been successfully improved by combining layers of PEDOT/PSS with layers of a secondary electrocatalytic material such as gold nanoparticles (PEDOT/PSS/AuNPs, copper phthalocyanine (PEDOT/PSS/CuPc or lutetium bisphthalocyanine (PEDOT/PSS/LuPc2. Layered composites exhibit synergistic effects that strongly enhance the electrocatalytic activity as indicated by the increase in intensity and the shift of the redox peaks to lower potentials. A remarkable improvement has been achieved using PEDOT/PSS/LuPc2, which exhibits excellent electrocatalytic activity towards the oxidation of catechol. The kinetic studies demonstrated diffusion-controlled processes at the electrode surfaces. The kinetic parameters such as Tafel slopes and charge transfer coefficient (α confirm the improved electrocatalytic activity of the layered electron mediators. The peak currents increased linearly with concentration of catechol and hydroquinone over the range of 1.5 × 10−4 to 4.0 × 10−6 mol·L−1 with a limit of detection on the scale of μmol·L−1. The layered composite hybrid systems were also found to be excellent electron mediators in biosensors containing tyrosinase and laccase, and they combine the recognition and biocatalytic properties of biomolecules with the unique catalytic features of composite materials. The observed increase in the intensity of the responses allowed detection limits of 1 × 10−7 mol·L−1 to be attained.

  17. Utilisation of Electronic Information Resources By Lecturers in ...

    African Journals Online (AJOL)

    This study assesses the use of information resources, specifically, electronic databases by lecturers/teachers in Universities and Colleges of Education in South Western Nigeria. Information resources are central to teachers' education. It provides lecturers/teachers access to information that enhances research and ...

  18. Preservation and conservation of electronic information resources of ...

    African Journals Online (AJOL)

    The major holdings of the broadcast libraries of the Nigerian Television Authority (NTA) are electronic information resources; therefore, providing safe places for general management of these resources have aroused interest in the industry in Nigeria for sometimes. The need to study the preservation and conservation of ...

  19. Using XML Technologies to Organize Electronic Reference Resources

    OpenAIRE

    Huser, Vojtech; Del Fiol, Guilherme; Rocha, Roberto A.

    2005-01-01

    Provision of access to reference electronic resources to clinicians is becoming increasingly important. We have created a framework for librarians to manage access to these resources at an enterprise level, rather than at the individual hospital libraries. We describe initial project requirements, implementation details, and some preliminary results.

  20. Euler European Libraries and Electronic Resources in Mathematical Sciences

    CERN Document Server

    The Euler Project. Karlsruhe

    The European Libraries and Electronic Resources (EULER) Project in Mathematical Sciences provides the EulerService site for searching out "mathematical resources such as books, pre-prints, web-pages, abstracts, proceedings, serials, technical reports preprints) and NetLab (for Internet resources), this outstanding engine is capable of simple, full, and refined searches. It also offers a browse option, which responds to entries in the author, keyword, and title fields. Further information about the Project is provided at the EULER homepage.

  1. Building an electronic resource collection a practical guide

    CERN Document Server

    Lee, Stuart D

    2004-01-01

    This practical book guides information professionals step-by-step through building and managing an electronic resource collection. It outlines the range of electronic products currently available in abstracting and indexing, bibliographic, and other services and then describes how to effectively select, evaluate and purchase them.

  2. Microbial biosensors

    International Nuclear Information System (INIS)

    Le Yu; Chen, Wilfred; Mulchandani, Ashok

    2006-01-01

    A microbial biosensor is an analytical device that couples microorganisms with a transducer to enable rapid, accurate and sensitive detection of target analytes in fields as diverse as medicine, environmental monitoring, defense, food processing and safety. The earlier microbial biosensors used the respiratory and metabolic functions of the microorganisms to detect a substance that is either a substrate or an inhibitor of these processes. Recently, genetically engineered microorganisms based on fusing of the lux, gfp or lacZ gene reporters to an inducible gene promoter have been widely applied to assay toxicity and bioavailability. This paper reviews the recent trends in the development and application of microbial biosensors. Current advances and prospective future direction in developing microbial biosensor have also been discussed

  3. Organizational matters of competition in electronic educational resources

    Directory of Open Access Journals (Sweden)

    Ирина Карловна Войтович

    2015-12-01

    Full Text Available The article examines the experience of the Udmurt State University in conducting competitions of educational publications and electronic resources. The purpose of such competitions is to provide methodological support to educational process. The main focus is on competition of electronic educational resources. The technology of such contests is discussed through detailed analysis of the main stages of the contest. It is noted that the main task of the preparatory stage of the competition is related to the development of regulations on competition and the definition of criteria for selection of the submitted works. The paper also proposes a system of evaluation criteria of electronic educational resources developed by members of the contest organizing committee and jury members. The article emphasizes the importance of not only the preparatory stages of the competition, but also measures for its completion, aimed at training teachers create quality e-learning resources.

  4. Fully integrated graphene electronic biosensor for label-free detection of lead (II) ion based on G-quadruplex structure-switching.

    Science.gov (United States)

    Li, Yijun; Wang, Cheng; Zhu, Yibo; Zhou, Xiaohong; Xiang, Yu; He, Miao; Zeng, Siyu

    2017-03-15

    This work presents a fully integrated graphene field-effect transistor (GFET) biosensor for the label-free detection of lead ions (Pb 2+ ) in aqueous-media, which first implements the G-quadruplex structure-switching biosensing principle in graphene nanoelectronics. We experimentally illustrate the biomolecular interplay that G-rich DNA single-strands with one-end confined on graphene surface can specifically interact with Pb 2+ ions and switch into G-quadruplex structures. Since the structure-switching of electrically charged DNA strands can disrupt the charge distribution in the vicinity of graphene surface, the carrier equilibrium in graphene sheet might be altered, and manifested by the conductivity variation of GFET. The experimental data and theoretical analysis show that our devices are capable of the label-free and specific quantification of Pb 2+ with a detection limit down to 163.7ng/L. These results first verify the signaling principle competency of G-quadruplex structure-switching in graphene electronic biosensors. Combining with the advantages of the compact device structure and convenient electrical signal, a label-free GFET biosensor for Pb 2+ monitoring is enabled with promising application potential. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Why and How to Measure the Use of Electronic Resources

    Directory of Open Access Journals (Sweden)

    Jean Bernon

    2008-11-01

    Full Text Available A complete overview of library activity implies a complete and reliable measurement of the use of both electronic resources and printed materials. This measurement is based on three sets of definitions: document types, use types and user types. There is a common model of definitions for printed materials, but a lot of questions and technical issues remain for electronic resources. In 2006 a French national working group studied these questions. It relied on the COUNTER standard, but found it insufficient and pointed out the need for local tools such as web markers and deep analysis of proxy logs. Within the French national consortium COUPERIN, a new working group is testing ERMS, SUSHI standards, Shibboleth authentication, along with COUNTER standards, to improve the counting of the electronic resources use. At this stage this counting is insufficient and its improvement will be a European challenge for the future.

  6. Direct electron transfer biosensor for hydrogen peroxide carrying nanocomplex composed of horseradish peroxidase and Au-nanoparticle – Characterization and application to bienzyme systems

    Directory of Open Access Journals (Sweden)

    Yusuke Okawa

    2015-09-01

    Full Text Available A reagentless electrochemical biosensor for hydrogen peroxide was fabricated. The sensor carries a monolayer of nanocomplex composed of horseradish peroxidase and Au-nanoparticle, and responds to hydrogen peroxide through the highly efficient direct electron transfer at a mild electrode potential without any soluble mediator. Formation of the nanocomplex was studied with visible spectroscopy and size exclusion chromatography. The sensor performance was analyzed based on a hydrodynamic electrochemical technique and enzyme kinetics. The sensor was applied to fabrication of sensors for glucose and uric acid through further modification of the nanocomplex-carrying electrode with the corresponding hydrogen peroxide-generating oxidases, glucose oxidase and urate oxidase, respectively.

  7. Access to electronic resources by visually impaired people

    Directory of Open Access Journals (Sweden)

    Jenny Craven

    2003-01-01

    Full Text Available Research into access to electronic resources by visually impaired people undertaken by the Centre for Research in Library and Information Management has not only explored the accessibility of websites and levels of awareness in providing websites that adhere to design for all principles, but has sought to enhance understanding of information seeking behaviour of blind and visually impaired people when using digital resources.

  8. Practical guide to electronic resources in the humanities

    CERN Document Server

    Dubnjakovic, Ana

    2010-01-01

    From full-text article databases to digitized collections of primary source materials, newly emerging electronic resources have radically impacted how research in the humanities is conducted and discovered. This book, covering high-quality, up-to-date electronic resources for the humanities, is an easy-to-use annotated guide for the librarian, student, and scholar alike. It covers online databases, indexes, archives, and many other critical tools in key humanities disciplines including philosophy, religion, languages and literature, and performing and visual arts. Succinct overviews of key eme

  9. Discipline, availability of electronic resources and the use of Finnish National Electronic Library - FinELib

    Directory of Open Access Journals (Sweden)

    Sanna Torma

    2004-01-01

    Full Text Available This study elaborated relations between digital library use by university faculty, users' discipline and the availability of key resources in the Finnish National Electronic Library (FinELib, Finnish national digital library, by using nationwide representative survey data. The results show that the perceived availability of key electronic resources by researchers in FinELib was a stronger predictor of the frequency and purpose of use of its services than users' discipline. Regardless of discipline a good perceived provision of central resources led to a more frequent use of FinELib. The satisfaction with the services did not vary with the discipline, but with the perceived availability of resources.

  10. Plasmonic biosensors.

    Science.gov (United States)

    Hill, Ryan T

    2015-01-01

    The unique optical properties of plasmon resonant nanostructures enable exploration of nanoscale environments using relatively simple optical characterization techniques. For this reason, the field of plasmonics continues to garner the attention of the biosensing community. Biosensors based on propagating surface plasmon resonances (SPRs) in films are the most well-recognized plasmonic biosensors, but there is great potential for the new, developing technologies to surpass the robustness and popularity of film-based SPR sensing. This review surveys the current plasmonic biosensor landscape with emphasis on the basic operating principles of each plasmonic sensing technique and the practical considerations when developing a sensing platform with the various techniques. The 'gold standard' film SPR technique is reviewed briefly, but special emphasis is devoted to the up-and-coming localized surface plasmon resonance and plasmonically coupled sensor technology. © 2014 Wiley Periodicals, Inc.

  11. Electrochemical biosensors

    CERN Document Server

    Cosnier, Serge

    2015-01-01

    "This is an excellent book on modern electrochemical biosensors, edited by Professor Cosnier and written by leading international experts. It covers state-of-the-art topics of this important field in a clear and timely manner."-Prof. Joseph Wang, UC San Diego, USA  "This book covers, in 13 well-illustrated chapters, the potential of electrochemical methods intimately combined with a biological component for the assay of various analytes of biological and environmental interest. Particular attention is devoted to the description of electrochemical microtools in close contact with a biological cell for exocytosis monitoring and to the use of nanomaterials in the electrochemical biosensor architecture for signal improvement. Interestingly, one chapter describes the concept and design of self-powered biosensors derived from biofuel cells. Each topic is reviewed by experts very active in the field. This timely book is well suited for providing a good overview of current research trends devoted to electrochemical...

  12. Implantable enzyme amperometric biosensors.

    Science.gov (United States)

    Kotanen, Christian N; Moussy, Francis Gabriel; Carrara, Sandro; Guiseppi-Elie, Anthony

    2012-05-15

    The implantable enzyme amperometric biosensor continues as the dominant in vivo format for the detection, monitoring and reporting of biochemical analytes related to a wide range of pathologies. Widely used in animal studies, there is increasing emphasis on their use in diabetes care and management, the management of trauma-associated hemorrhage and in critical care monitoring by intensivists in the ICU. These frontier opportunities demand continuous indwelling performance for up to several years, well in excess of the currently approved seven days. This review outlines the many challenges to successful deployment of chronically implantable amperometric enzyme biosensors and emphasizes the emerging technological approaches in their continued development. The foreign body response plays a prominent role in implantable biotransducer failure. Topics considering the approaches to mitigate the inflammatory response, use of biomimetic chemistries, nanostructured topographies, drug eluting constructs, and tissue-to-device interface modulus matching are reviewed. Similarly, factors that influence biotransducer performance such as enzyme stability, substrate interference, mediator selection and calibration are reviewed. For the biosensor system, the opportunities and challenges of integration, guided by footprint requirements, the limitations of mixed signal electronics, and power requirements, has produced three systems approaches. The potential is great. However, integration along the multiple length scales needed to address fundamental issues and integration across the diverse disciplines needed to achieve success of these highly integrated systems, continues to be a challenge in the development and deployment of implantable amperometric enzyme biosensor systems. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Access to electronic information resources by students of federal ...

    African Journals Online (AJOL)

    The paper discusses access to electronic information resources by students of Federal Colleges of Education in Eha-Amufu and Umunze. Descriptive survey design was used to investigate sample of 526 students. Sampling technique used was a Multi sampling technique. Data for the study were generated using ...

  14. Electronic Commerce Resource Centers. An Industry--University Partnership.

    Science.gov (United States)

    Gulledge, Thomas R.; Sommer, Rainer; Tarimcilar, M. Murat

    1999-01-01

    Electronic Commerce Resource Centers focus on transferring emerging technologies to small businesses through university/industry partnerships. Successful implementation hinges on a strategic operating plan, creation of measurable value for customers, investment in customer-targeted training, and measurement of performance outputs. (SK)

  15. ANALYTICAL REVIEW OF ELECTRONIC RESOURCES FOR THE STUDY OF LATIN

    Directory of Open Access Journals (Sweden)

    Olena Yu. Balalaieva

    2014-04-01

    Full Text Available The article investigates the current state of development of e-learning content in the Latin language. It is noted that the introduction of ICT in the educational space has expanded the possibility of studying Latin, opened access to digital libraries resources, made it possible to use scientific and educational potential and teaching Latin best practices of world's leading universities. A review of foreign and Ukrainian information resources and electronic editions for the study of Latin is given. Much attention was paid to the didactic potential of local and online multimedia courses of Latin, electronic textbooks, workbooks of interactive tests and exercises, various dictionaries and software translators, databases and digital libraries. Based on analysis of the world market of educational services and products the main trends in the development of information resources and electronic books are examined. It was found that multimedia courses with interactive exercises or workbooks with interactive tests, online dictionaries and translators are the most widely represented and demanded. The noticeable lagging of Ukrainian education and computer linguistics in quantitative and qualitative measures in this industry is established. The obvious drawback of existing Ukrainian resources and electronic editions for the study of Latin is their noninteractive nature. The prospects of e-learning content in Latin in Ukraine are outlined.

  16. Adoption and use of electronic information resources by medical ...

    African Journals Online (AJOL)

    This study investigated the adoption and use of electronic information resources by medical science students of the University of Benin. The descriptive survey research design was adopted for the study and 390 students provided the data. Data collected were analysed with descriptive Statistics(Simple percentage and ...

  17. Modern ICT Tools: Online Electronic Resources Sharing Using Web ...

    African Journals Online (AJOL)

    Modern ICT Tools: Online Electronic Resources Sharing Using Web 2.0 and Its Implications For Library And Information Practice In Nigeria. ... The PDF file you selected should load here if your Web browser has a PDF reader plug-in installed (for example, a recent version of Adobe Acrobat Reader). If you would like more ...

  18. Technical Communicator: A New Model for the Electronic Resources Librarian?

    Science.gov (United States)

    Hulseberg, Anna

    2016-01-01

    This article explores whether technical communicator is a useful model for electronic resources (ER) librarians. The fields of ER librarianship and technical communication (TC) originated and continue to develop in relation to evolving technologies. A review of the literature reveals four common themes for ER librarianship and TC. While the…

  19. Nano-arrays of SAM by dip-pen nanowriting (DPN) technique for futuristic bio-electronic and bio-sensor applications

    International Nuclear Information System (INIS)

    Agarwal, Pankaj B.; Kumar, A.; Saravanan, R.; Sharma, A.K.; Shekhar, Chandra

    2010-01-01

    Nano-arrays of bio-molecules have potential applications in many areas namely, bio-sensors, bio/molecular electronics and virus detection. Spot array, micro-contact printing and photolithography are used for micron size array fabrications while Dip-Pen Nanowriting (DPN) is employed for submicron/nano size arrays. We have fabricated nano-dots of 16-MHA (16-mercaptohexadecanoic acid) self-assembled monolayer (SAM) on gold substrate by DPN technique with different dwell time under varying relative humidity. These patterns were imaged in the same system in LFM (Lateral Force Microscopy) mode with fast scanning speed (5 Hz). The effect of humidity on size variation of nano-dots has been studied. During experiments, relative humidity (RH) was varied from 20% to 60%, while the temperature was kept constant ∼ 25 o C. The minimum measured diameter of the dot is ∼ 294 nm at RH = 20% for a dwell time of 2 s. The thickness of the 16-MHA dots, estimated in NanoRule image analysis software is ∼ 2 nm, which agrees well with the length of single MHA molecule (2.2 nm). The line profile has been used to estimate the size and thickness of dots. The obtained results will be useful in further development of nano-array based bio-sensors and bio-electronic devices.

  20. An enzymatic biosensor based on three-dimensional ZnO nanotetrapods spatial net modified AlGaAs/GaAs high electron mobility transistors

    Energy Technology Data Exchange (ETDEWEB)

    Song, Yu [State Key Laboratory for Advanced Metals and Materials, School of Materials Science and Engineering, University of Science and Technology, Beijing 100083 (China); Bioengineering Program, Lehigh University, Bethlehem, Pennsylvania 18015 (United States); Zhang, Xiaohui; Yan, Xiaoqin; Liao, Qingliang; Wang, Zengze; Zhang, Yue, E-mail: yuezhang@ustb.edu.cn [State Key Laboratory for Advanced Metals and Materials, School of Materials Science and Engineering, University of Science and Technology, Beijing 100083 (China)

    2014-11-24

    We designed and constructed three dimensional (3D) zinc oxide Nanotetrapods (T-ZnOs) modified AlGaAs/GaAs high electron mobility transistors (HEMTs) for enzymatic uric acid (UA) detection. The chemical vapor deposition synthesized T-ZnOs was distributed on the gate areas of HEMTs in order to immobilize uricase and improve the sensitivity of the HEMTs. Combining with the high efficiency of enzyme immobilization by T-ZnOs and high sensitivity from HEMT, the as-constructed uricase/T-ZnOs/HEMTs biosensor showed fast response towards UA at ∼1 s, wide linear range from 0.2 nM to 0.2 mM and the low detect limit at 0.2 nM. The results point out an avenue to design electronic device as miniaturized lab-on-chip device for high sensitive and specific in biomedical and clinical diagnosis applications.

  1. Detection of BCG bacteria using a magnetoresistive biosensor: A step towards a fully electronic platform for tuberculosis point-of-care detection.

    Science.gov (United States)

    Barroso, Teresa G; Martins, Rui C; Fernandes, Elisabete; Cardoso, Susana; Rivas, José; Freitas, Paulo P

    2018-02-15

    Tuberculosis is one of the major public health concerns. This highly contagious disease affects more than 10.4 million people, being a leading cause of morbidity by infection. Tuberculosis is diagnosed at the point-of-care by the Ziehl-Neelsen sputum smear microscopy test. Ziehl-Neelsen is laborious, prone to human error and infection risk, with a limit of detection of 10 4 cells/mL. In resource-poor nations, a more practical test, with lower detection limit, is paramount. This work uses a magnetoresistive biosensor to detect BCG bacteria for tuberculosis diagnosis. Herein we report: i) nanoparticle assembly method and specificity for tuberculosis detection; ii) demonstration of proportionality between BCG cell concentration and magnetoresistive voltage signal; iii) application of multiplicative signal correction for systematic effects removal; iv) investigation of calibration effectiveness using chemometrics methods; and v) comparison with state-of-the-art point-of-care tuberculosis biosensors. Results present a clear correspondence between voltage signal and cell concentration. Multiplicative signal correction removes baseline shifts within and between biochip sensors, allowing accurate and precise voltage signal between different biochips. The corrected signal was used for multivariate regression models, which significantly decreased the calibration standard error from 0.50 to 0.03log 10 (cells/mL). Results show that Ziehl-Neelsen detection limits and below are achievable with the magnetoresistive biochip, when pre-processing and chemometrics are used. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. MODEL OF AN ELECTRONIC EDUCATIONAL RESOURCE OF NEW GENERATION

    Directory of Open Access Journals (Sweden)

    Anatoliy V. Loban

    2016-01-01

    Full Text Available The mathematical structure of the modular architecture of an electronic educational resource (EER of new generation, which allows to decompose the process of studying the subjects of the course at a hierarchically ordered set of data (knowledge and procedures for manipulating them, to determine the roles of participants of process of training of and technology the development and use of EOR in the study procrate.

  3. PRINCIPLES OF AFFINITY-BASED BIOSENSORS

    Science.gov (United States)

    Despite the amount of resources that have been invested by national and international academic, government, and commercial sectors to develop affinity-based biosensor products, little obvious success has been realized through commercialization of these devices for specific applic...

  4. Biosensor. Seitai sensa

    Energy Technology Data Exchange (ETDEWEB)

    Karube, I [The Univ. of Tokyo, Tokyo (Japan). Research Center for Advanced Science and Technology

    1993-06-15

    Present state of the art of biosensors is described by taking taste sensors and odor sensors as examples. Bio-devices that response only to specific chemical substances are made using membranes that recognize particular molecules. Biosensors are constructed in combination of bio-devices with electronics devices that transduce the response of bio-devices to electric signals. Enzymes are used often as bio-devices to recognize molecules. They recognize strictly chemical substances and promote chemical reactions. Devices to measure electrochemically substances consumed or produced in the reactions serve as sensors. For taste sensors, inosinic acid or glutamic acid that is a component of taste, is recognized and measured. Combination of various bio-devices other than enzymes with various transducers makes it possible to produce biosensors based on a variety of principles. Odor sensors recognize odors by measuring frequency change of the electrode of quartz oscillator. The change occurs with weight change due to odorous substances absorbed on the oscillator electrode coated with lipids which exist in olfactory cells. 1 ref., 1 fig.

  5. End-of-life resource recovery from emerging electronic products

    DEFF Research Database (Denmark)

    Parajuly, Keshav; Habib, Komal; Cimpan, Ciprian

    2016-01-01

    Integrating product design with appropriate end-of-life (EoL) processing is widely recognized to have huge potentials in improving resource recovery from electronic products. In this study, we investigate both the product characteristics and EoL processing of robotic vacuum cleaner (RVC), as a case...... of emerging electronic product, in order to understand the recovery fate of different materials and its linkage to product design. Ten different brands of RVC were dismantled and their material composition and design profiles were studied. Another 125 RVCs (349 kg) were used for an experimental trial...... at a conventional ‘shred-and-separate’ type preprocessing plant in Denmark. A detailed material flow analysis was performed throughout the recycling chain. The results show a mismatch between product design and EoL processing, and the lack of practical implementation of ‘Design for EoL’ thinking. In the best...

  6. Analysis of Human Resources Management Strategy in China Electronic Commerce Enterprises

    Science.gov (United States)

    Shao, Fang

    The paper discussed electronic-commerce's influence on enterprise human resources management, proposed and proved the human resources management strategy which electronic commerce enterprise should adopt from recruitment strategy to training strategy, keeping talent strategy and other ways.

  7. Effects of Electronic Information Resources Skills Training for Lecturers on Pedagogical Practices and Research Productivity

    Science.gov (United States)

    Bhukuvhani, Crispen; Chiparausha, Blessing; Zuvalinyenga, Dorcas

    2012-01-01

    Lecturers use various electronic resources at different frequencies. The university library's information literacy skills workshops and seminars are the main sources of knowledge of accessing electronic resources. The use of electronic resources can be said to have positively affected lecturers' pedagogical practices and their work in general. The…

  8. Electronic Resources and Mission Creep: Reorganizing the Library for the Twenty-First Century

    Science.gov (United States)

    Stachokas, George

    2009-01-01

    The position of electronic resources librarian was created to serve as a specialist in the negotiation of license agreements for electronic resources, but mission creep has added more functions to the routine work of electronic resources such as cataloging, gathering information for collection development, and technical support. As electronic…

  9. An ultrasensitive electrochemical biosensor for glucose using CdTe-CdS core-shell quantum dot as ultrafast electron transfer relay between graphene-gold nanocomposite and gold nanoparticle

    International Nuclear Information System (INIS)

    Gu Zhiguo; Yang Shuping; Li Zaijun; Sun Xiulan; Wang Guangli; Fang Yinjun; Liu Junkang

    2011-01-01

    Graphical abstract: We first reported an ultrasensitive electrochemical biosensor for glucose using CdTe-CdS core-shell quantum dot as ultrafast electron transfer relay between graphene-gold nanocomposite and gold nanoparticle. Since promising their electrocatalytic synergy towards glucose was achieved, the biosensor showed high sensitivity (5762.8 nA nM -1 cm -2 ), low detection limit (S/N = 3) (3 x 10 -12 M) and fast response time (0.045 s). - Abstract: The paper reported an ultrasensitive electrochemical biosensor for glucose which was based on CdTe-CdS core-shell quantum dot as ultrafast electron transfer relay between graphene-gold nanocomposite and gold nanoparticle. Since efficient electron transfer between glucose oxidase and the electrode was achieved, the biosensor showed high sensitivity (5762.8 nA nM -1 cm -2 ), low detection limit (S/N = 3) (3 x 10 -12 M), fast response time (0.045 s), wide calibration range (from 1 x 10 -11 M to 1 x 10 -8 M) and good long-term stability (26 weeks). The apparent Michaelis-Menten constant of the glucose oxidase on the medium, 5.24 x 10 -6 mM, indicates excellent bioelectrocatalytic activity of the immobilized enzyme towards glucose oxidation. Moreover, the effects of omitting graphene-gold nanocomposite, CdTe-CdS core-shell quantum dot and gold nanoparticle were also investigated. The result showed sensitivity of the biosensor is 7.67-fold better if graphene-gold nanocomposite, CdTe-CdS core-shell quantum dot and gold nanoparticle are used. This could be ascribed to improvement of the conductivity between graphene nanosheets due to introduction of gold nanoparticles, ultrafast charge transfer from CdTe-CdS core-shell quantum dot to graphene nanosheets and gold nanoparticle due to unique electrochemical properties of the CdTe-CdS core-shell quantum dot and good biocompatibility of gold nanoparticle for glucose oxidase. The biosensor is of best sensitivity in all glucose biosensors based on graphene nanomaterials up to

  10. An ultrasensitive electrochemical biosensor for glucose using CdTe-CdS core-shell quantum dot as ultrafast electron transfer relay between graphene-gold nanocomposite and gold nanoparticle

    Energy Technology Data Exchange (ETDEWEB)

    Gu Zhiguo; Yang Shuping [School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122 (China); Li Zaijun, E-mail: zaijunli@263.net [School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122 (China); Sun Xiulan [School of Food Science and Technology, Jiangnan University, Wuxi 214122 (China); Wang Guangli [School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122 (China); Fang Yinjun [Zhejiang Zanyu Technology Co., Ltd., Hangzhou 310009 (China); Liu Junkang [School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122 (China)

    2011-10-30

    Graphical abstract: We first reported an ultrasensitive electrochemical biosensor for glucose using CdTe-CdS core-shell quantum dot as ultrafast electron transfer relay between graphene-gold nanocomposite and gold nanoparticle. Since promising their electrocatalytic synergy towards glucose was achieved, the biosensor showed high sensitivity (5762.8 nA nM{sup -1} cm{sup -2}), low detection limit (S/N = 3) (3 x 10{sup -12} M) and fast response time (0.045 s). - Abstract: The paper reported an ultrasensitive electrochemical biosensor for glucose which was based on CdTe-CdS core-shell quantum dot as ultrafast electron transfer relay between graphene-gold nanocomposite and gold nanoparticle. Since efficient electron transfer between glucose oxidase and the electrode was achieved, the biosensor showed high sensitivity (5762.8 nA nM{sup -1} cm{sup -2}), low detection limit (S/N = 3) (3 x 10{sup -12} M), fast response time (0.045 s), wide calibration range (from 1 x 10{sup -11} M to 1 x 10{sup -8} M) and good long-term stability (26 weeks). The apparent Michaelis-Menten constant of the glucose oxidase on the medium, 5.24 x 10{sup -6} mM, indicates excellent bioelectrocatalytic activity of the immobilized enzyme towards glucose oxidation. Moreover, the effects of omitting graphene-gold nanocomposite, CdTe-CdS core-shell quantum dot and gold nanoparticle were also investigated. The result showed sensitivity of the biosensor is 7.67-fold better if graphene-gold nanocomposite, CdTe-CdS core-shell quantum dot and gold nanoparticle are used. This could be ascribed to improvement of the conductivity between graphene nanosheets due to introduction of gold nanoparticles, ultrafast charge transfer from CdTe-CdS core-shell quantum dot to graphene nanosheets and gold nanoparticle due to unique electrochemical properties of the CdTe-CdS core-shell quantum dot and good biocompatibility of gold nanoparticle for glucose oxidase. The biosensor is of best sensitivity in all glucose

  11. Electronic Document Management: A Human Resource Management Case Study

    Directory of Open Access Journals (Sweden)

    Thomas Groenewald

    2004-11-01

    Full Text Available This case study serve as exemplar regarding what can go wrong with the implementation of an electronic document management system. Knowledge agility and knowledge as capital, is outlined against the backdrop of the information society and knowledge economy. The importance of electronic document management and control is sketched thereafter. The literature review is concluded with the impact of human resource management on knowledge agility, which includes references to the learning organisation and complexity theory. The intervention methodology, comprising three phases, follows next. The results of the three phases are presented thereafter. Partial success has been achieved with improving the human efficacy of electronic document management, however the client opted to discontinue the system in use. Opsomming Die gevalle studie dien as voorbeeld van wat kan verkeerd loop met die implementering van ’n elektroniese dokumentbestuur sisteem. Teen die agtergrond van die inligtingsgemeenskap en kennishuishouding word kennissoepelheid en kennis as kapitaal bespreek. Die literatuurstudie word afgesluit met die inpak van menslikehulpbronbestuur op kennissoepelheid, wat ook die verwysings na die leerorganisasie en kompleksietydsteorie insluit. Die metodologie van die intervensie, wat uit drie fases bestaan, volg daarna. Die resultate van die drie fases word vervolgens aangebied. Slegs gedeelte welslae is behaal met die verbetering van die menslike doeltreffendheid ten opsigte van elektroniese dokumentbestuur. Die klient besluit egter om nie voort te gaan om die huidige sisteem te gebruik nie.

  12. Prospects of conducting polymers in biosensors

    International Nuclear Information System (INIS)

    Malhotra, Bansi D.; Chaubey, Asha; Singh, S.P.

    2006-01-01

    Applications of conducting polymers to biosensors have recently aroused much interest. This is because these molecular electronic materials offer control of different parameters such as polymer layer thickness, electrical properties and bio-reagent loading, etc. Moreover, conducting polymer based biosensors are likely to cater to the pressing requirements such as biocompatibility, possibility of in vivo sensing, continuous monitoring of drugs or metabolites, multi-parametric assays, miniaturization and high information density. This paper deals with the emerging trends in conducting polymer based biosensors during the last about 5 years

  13. Biosensors and preparation thereof

    NARCIS (Netherlands)

    2008-01-01

    A low-temp. prepn. method for a biosensor device with a layer of reagent on the sensor surface is disclosed. During manufg. biol. interaction between the biosensor substrate and the reagent layer material is reduced, e.g. by cooling the biosensor substrate and depositing the reagent layer on the

  14. Cholinesterase-based biosensors.

    Science.gov (United States)

    Štěpánková, Šárka; Vorčáková, Katarína

    2016-01-01

    Recently, cholinesterase-based biosensors are widely used for assaying anticholinergic compounds. Primarily biosensors based on enzyme inhibition are useful analytical tools for fast screening of inhibitors, such as organophosphates and carbamates. The present review is aimed at compilation of the most important facts about cholinesterase based biosensors, types of physico-chemical transduction, immobilization strategies and practical applications.

  15. Electronic Safety Resource Tools -- Supporting Hydrogen and Fuel Cell Commercialization

    Energy Technology Data Exchange (ETDEWEB)

    Barilo, Nick F.

    2014-09-29

    The Pacific Northwest National Laboratory (PNNL) Hydrogen Safety Program conducted a planning session in Los Angeles, CA on April 1, 2014 to consider what electronic safety tools would benefit the next phase of hydrogen and fuel cell commercialization. A diverse, 20-person team led by an experienced facilitator considered the question as it applied to the eight most relevant user groups. The results and subsequent evaluation activities revealed several possible resource tools that could greatly benefit users. The tool identified as having the greatest potential for impact is a hydrogen safety portal, which can be the central location for integrating and disseminating safety information (including most of the tools identified in this report). Such a tool can provide credible and reliable information from a trustworthy source. Other impactful tools identified include a codes and standards wizard to guide users through a series of questions relating to application and specific features of the requirements; a scenario-based virtual reality training for first responders; peer networking tools to bring users from focused groups together to discuss and collaborate on hydrogen safety issues; and a focused tool for training inspectors. Table ES.1 provides results of the planning session, including proposed new tools and changes to existing tools.

  16. Biosensors of bacterial cells.

    Science.gov (United States)

    Burlage, Robert S; Tillmann, Joshua

    2017-07-01

    Biosensors are devices which utilize both an electrical component (transducer) and a biological component to study an environment. They are typically used to examine biological structures, organisms and processes. The field of biosensors has now become so large and varied that the technology can often seem impenetrable. Yet the principles which underlie the technology are uncomplicated, even if the details of the mechanisms are elusive. In this review we confine our analysis to relatively current advancements in biosensors for the detection of whole bacterial cells. This includes biosensors which rely on an added labeled component and biosensors which do not have a labeled component and instead detect the binding event or bound structure on the transducer. Methods to concentrate the bacteria prior to biosensor analysis are also described. The variety of biosensor types and their actual and potential uses are described. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Biosensors a promising future in measurements

    International Nuclear Information System (INIS)

    Saleem, Muhammad

    2013-01-01

    A biosensor is an analytical device which can be used to convert the existence of a molecule or compound into a measurable and useful signal. Biosensors use stimulus to translate changes to recognisable signals and have great importance to society. Applications include diagnosis tools for diseases, security appliances, and other biomedical equipments. Biosensors can also be used in the detection of pathogens and other microbes in foodstuffs, drugs and processing industries. Enormous progress and advancement has been witnessed in this area. Research and development in micro level systems serves to interface biology with novel materials such as nanomaterial. Development of high speed and accurate electronic devices tfor use in medicine and energy storage (such as biofuel cells) is one of the target areas. This paper discusses the importance, use and current and future trend in the application of biosensors

  18. Controlling user access to electronic resources without password

    Science.gov (United States)

    Smith, Fred Hewitt

    2015-06-16

    Described herein are devices and techniques for remotely controlling user access to a restricted computer resource. The process includes pre-determining an association of the restricted computer resource and computer-resource-proximal environmental information. Indicia of user-proximal environmental information are received from a user requesting access to the restricted computer resource. Received indicia of user-proximal environmental information are compared to associated computer-resource-proximal environmental information. User access to the restricted computer resource is selectively granted responsive to a favorable comparison in which the user-proximal environmental information is sufficiently similar to the computer-resource proximal environmental information. In at least some embodiments, the process further includes comparing user-supplied biometric measure and comparing it with a predetermined association of at least one biometric measure of an authorized user. Access to the restricted computer resource is granted in response to a favorable comparison.

  19. Gold nanoparticle-based electrochemical biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Pingarron, Jose M.; Yanez-Sedeno, Paloma; Gonzalez-Cortes, Araceli [Department of Analytical Chemistry, Faculty of Chemistry, University Complutense of Madrid, 28040 Madrid (Spain)

    2008-08-01

    The unique properties of gold nanoparticles to provide a suitable microenvironment for biomolecules immobilization retaining their biological activity, and to facilitate electron transfer between the immobilized proteins and electrode surfaces, have led to an intensive use of this nanomaterial for the construction of electrochemical biosensors with enhanced analytical performance with respect to other biosensor designs. Recent advances in this field are reviewed in this article. The advantageous operational characteristics of the biosensing devices designed making use of gold nanoparticles are highlighted with respect to non-nanostructured biosensors and some illustrative examples are commented. Electrochemical enzyme biosensors including those using hybrid materials with carbon nanotubes and polymers, sol-gel matrices, and layer-by-layer architectures are considered. Moreover, electrochemical immunosensors in which gold nanoparticles play a crucial role in the electrode transduction enhancement of the affinity reaction as well as in the efficiency of immunoreagents immobilization in a stable mode are reviewed. Similarly, recent advances in the development of DNA biosensors using gold nanoparticles to improve DNA immobilization on electrode surfaces and as suitable labels to improve detection of hybridization events are considered. Finally, other biosensors designed with gold nanoparticles oriented to electrically contact redox enzymes to electrodes by a reconstitution process and to the study of direct electron transfer between redox proteins and electrode surfaces have also been treated. (author)

  20. Gold nanoparticle-based electrochemical biosensors

    International Nuclear Information System (INIS)

    Pingarron, Jose M.; Yanez-Sedeno, Paloma; Gonzalez-Cortes, Araceli

    2008-01-01

    The unique properties of gold nanoparticles to provide a suitable microenvironment for biomolecules immobilization retaining their biological activity, and to facilitate electron transfer between the immobilized proteins and electrode surfaces, have led to an intensive use of this nanomaterial for the construction of electrochemical biosensors with enhanced analytical performance with respect to other biosensor designs. Recent advances in this field are reviewed in this article. The advantageous operational characteristics of the biosensing devices designed making use of gold nanoparticles are highlighted with respect to non-nanostructured biosensors and some illustrative examples are commented. Electrochemical enzyme biosensors including those using hybrid materials with carbon nanotubes and polymers, sol-gel matrices, and layer-by-layer architectures are considered. Moreover, electrochemical immunosensors in which gold nanoparticles play a crucial role in the electrode transduction enhancement of the affinity reaction as well as in the efficiency of immunoreagents immobilization in a stable mode are reviewed. Similarly, recent advances in the development of DNA biosensors using gold nanoparticles to improve DNA immobilization on electrode surfaces and as suitable labels to improve detection of hybridization events are considered. Finally, other biosensors designed with gold nanoparticles oriented to electrically contact redox enzymes to electrodes by a reconstitution process and to the study of direct electron transfer between redox proteins and electrode surfaces have also been treated

  1. The Internet School of Medicine: use of electronic resources by medical trainees and the reliability of those resources.

    Science.gov (United States)

    Egle, Jonathan P; Smeenge, David M; Kassem, Kamal M; Mittal, Vijay K

    2015-01-01

    Electronic sources of medical information are plentiful, and numerous studies have demonstrated the use of the Internet by patients and the variable reliability of these sources. Studies have investigated neither the use of web-based resources by residents, nor the reliability of the information available on these websites. A web-based survey was distributed to surgical residents in Michigan and third- and fourth-year medical students at an American allopathic and osteopathic medical school and a Caribbean allopathic school regarding their preferred sources of medical information in various situations. A set of 254 queries simulating those faced by medical trainees on rounds, on a written examination, or during patient care was developed. The top 5 electronic resources cited by the trainees were evaluated for their ability to answer these questions accurately, using standard textbooks as the point of reference. The respondents reported a wide variety of overall preferred resources. Most of the 73 responding medical trainees favored textbooks or board review books for prolonged studying, but electronic resources are frequently used for quick studying, clinical decision-making questions, and medication queries. The most commonly used electronic resources were UpToDate, Google, Medscape, Wikipedia, and Epocrates. UpToDate and Epocrates had the highest percentage of correct answers (47%) and Wikipedia had the lowest (26%). Epocrates also had the highest percentage of wrong answers (30%), whereas Google had the lowest percentage (18%). All resources had a significant number of questions that they were unable to answer. Though hardcopy books have not been completely replaced by electronic resources, more than half of medical students and nearly half of residents prefer web-based sources of information. For quick questions and studying, both groups prefer Internet sources. However, the most commonly used electronic resources fail to answer clinical queries more than half

  2. High sensitivity cardiac troponin I detection in physiological environment using AlGaN/GaN High Electron Mobility Transistor (HEMT) Biosensors.

    Science.gov (United States)

    Sarangadharan, Indu; Regmi, Abiral; Chen, Yen-Wen; Hsu, Chen-Pin; Chen, Pei-Chi; Chang, Wen-Hsin; Lee, Geng-Yen; Chyi, Jen-Inn; Shiesh, Shu-Chu; Lee, Gwo-Bin; Wang, Yu-Lin

    2018-02-15

    In this study, we report the development of a high sensitivity assay for the detection of cardiac troponin I using electrical double layer gated high field AlGaN/GaN HEMT biosensor. The unique gating mechanism overcomes the drawback of charge screening seen in traditional FET based biosensors, allowing detection of target proteins in physiological solutions without sample processing steps. Troponin I specific antibody and aptamer are used as receptors. The tests carried out using purified protein solution and clinical serum samples depict high sensitivity, specificity and wide dynamic range (0.006-148ng/mL). No additional wash or sample pre-treatment steps are required, which greatly simplifies the biosensor system. The miniaturized HEMT chip is packaged in a polymer substrate and easily integrated with a portable measurement unit, to carry out quantitative troponin I detection in serum samples with < 2µl sample volume in 5min. The integrated prototype biosensor unit demonstrates the potential of the method as a rapid, inexpensive, high sensitivity CVD biomarker assay. The highly simplified protocols and enhanced sensor performance make our biosensor an ideal choice for point of care diagnostics and personal healthcare systems. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Developing Humanities Collections in the Digital Age: Exploring Humanities Faculty Engagement with Electronic and Print Resources

    Science.gov (United States)

    Kachaluba, Sarah Buck; Brady, Jessica Evans; Critten, Jessica

    2014-01-01

    This article is based on quantitative and qualitative research examining humanities scholars' understandings of the advantages and disadvantages of print versus electronic information resources. It explores how humanities' faculty members at Florida State University (FSU) use print and electronic resources, as well as how they perceive these…

  4. Electronic resource management practical perspectives in a new technical services model

    CERN Document Server

    Elguindi, Anne

    2012-01-01

    A significant shift is taking place in libraries, with the purchase of e-resources accounting for the bulk of materials spending. Electronic Resource Management makes the case that technical services workflows need to make a corresponding shift toward e-centric models and highlights the increasing variety of e-formats that are forcing new developments in the field.Six chapters cover key topics, including: technical services models, both past and emerging; staffing and workflow in electronic resource management; implementation and transformation of electronic resource management systems; the ro

  5. Biosensors and bioelectronics

    CERN Document Server

    Karunakaran, Chandran; Benjamin, Robson

    2015-01-01

    Biosensors and Bioelectronics presents the rapidly evolving methodologies that are relevant to biosensors and bioelectronics fabrication and characterization. The book provides a comprehensive understanding of biosensor functionality, and is an interdisciplinary reference that includes a range of interwoven contributing subjects, including electrochemistry, nanoparticles, and conducting polymers. Authored by a team of bioinstrumentation experts, this book serves as a blueprint for performing advanced fabrication and characterization of sensor systems-arming readers with an application-based re

  6. Electronic resources access and usage among the postgraduates of ...

    African Journals Online (AJOL)

    ... and usage among the postgraduates of a Nigerian University of Technology. ... faced by postgraduates in using e-resources include takes too much time to find, ... Resources, Access, Use, Postgraduat, Students, University, Technology, Nigeria ... By Country · List All Titles · Free To Read Titles This Journal is Open Access.

  7. Strategic Planning for Electronic Resources Management: A Case Study at Gustavus Adolphus College

    Science.gov (United States)

    Hulseberg, Anna; Monson, Sarah

    2009-01-01

    Electronic resources, the tools we use to manage them, and the needs and expectations of our users are constantly evolving; at the same time, the roles, responsibilities, and workflow of the library staff who manage e-resources are also in flux. Recognizing a need to be more intentional and proactive about how we manage e-resources, the…

  8. impact of the use of electronic resources on research output

    African Journals Online (AJOL)

    manda

    ... Julita Nawe. University of Dar Es Salaam Library, P.O. Box 35092, Dar Es Salaam, Tanzania .... significantly, while 28.3% observed that quality of service to the community had improved .... resources and evaluate them is an important area.

  9. Nucleic Acids and Enzymes at Electrodes: Electrochemical Nanomedical Biosensors and Biofuel Cell Development

    DEFF Research Database (Denmark)

    Ferapontova, Elena

    Starting from the development of the first electrochemical biosensor for glucose, as far as in 1962, the electrochemical biosensor research area underwent a dramatic evolution both in scientific and commercial directions. At present, electrochemical biosensors are widely used in medical practice,...... perspectives of the biosensor research and such biotechnological applications as enzyme electrodes for sustainable energy production (6) will be discussed.......Starting from the development of the first electrochemical biosensor for glucose, as far as in 1962, the electrochemical biosensor research area underwent a dramatic evolution both in scientific and commercial directions. At present, electrochemical biosensors are widely used in medical practice......, by offering extremely sensitive and accurate yet simple, rapid, and inexpensive biosensing platforms (1). In this talk, I will discuss the developed at iNANO reagentless enzymatic biosensors, in which the enzyme is directly electronically coupled to the electrode (1-3), and advanced genosensor platforms...

  10. Preservation of and Permanent Access to Electronic Information Resources

    National Research Council Canada - National Science Library

    Hodge, Gail

    2004-01-01

    The rapid growth in the creation and dissemination of electronic information has emphasized the digital environment's speed and ease of dissemination with little regard for its long-term preservation and access...

  11. Electronic conferencing for continuing medical education: a resource survey.

    Science.gov (United States)

    Sternberg, R J

    1986-10-01

    The use of electronic technologies to link participants for education conferences is an option for providers of Continuing Medical Education. In order to profile the kinds of electronic networks currently offering audio- or videoteleconferences for physician audiences, a survey was done during late 1985. The information collected included range of services, fees, and geographic areas served. The results show a broad diversity of providers providing both interactive and didactic programming to both physicians and other health care professionals.

  12. Biosensors for Cell Analysis.

    Science.gov (United States)

    Zhou, Qing; Son, Kyungjin; Liu, Ying; Revzin, Alexander

    2015-01-01

    Biosensors first appeared several decades ago to address the need for monitoring physiological parameters such as oxygen or glucose in biological fluids such as blood. More recently, a new wave of biosensors has emerged in order to provide more nuanced and granular information about the composition and function of living cells. Such biosensors exist at the confluence of technology and medicine and often strive to connect cell phenotype or function to physiological or pathophysiological processes. Our review aims to describe some of the key technological aspects of biosensors being developed for cell analysis. The technological aspects covered in our review include biorecognition elements used for biosensor construction, methods for integrating cells with biosensors, approaches to single-cell analysis, and the use of nanostructured biosensors for cell analysis. Our hope is that the spectrum of possibilities for cell analysis described in this review may pique the interest of biomedical scientists and engineers and may spur new collaborations in the area of using biosensors for cell analysis.

  13. Controlling user access to electronic resources without password

    Science.gov (United States)

    Smith, Fred Hewitt

    2017-08-22

    Described herein are devices and techniques for remotely controlling user access to a restricted computer resource. The process includes obtaining an image from a communication device of a user. An individual and a landmark are identified within the image. Determinations are made that the individual is the user and that the landmark is a predetermined landmark. Access to a restricted computing resource is granted based on the determining that the individual is the user and that the landmark is the predetermined landmark. Other embodiments are disclosed.

  14. Nanocomposite/Hybrid Materials of Electroactive Polymers With Inorganic Oxides for Biosensor Applications

    National Research Council Canada - National Science Library

    Wei, Yen

    2001-01-01

    As proposed, we have successfully synthesized new electroactive and electronically conductive polyaniline polymethacrylate-silica nanocomposites and fabricated biosensor devices, aimed for detecting...

  15. Electron beam pasteurised oil palm waste: a potential feed resource

    International Nuclear Information System (INIS)

    Mat Rasol Awang; Hassan Hamdani Mutaat; Tamikazu Kume; Tachibana, H.

    2002-01-01

    Pasteurization of oil palm empty fruit bunch (EFB) was performed using electron beam single sided irradiation. The dose profiles of oil palm EFB samples for different thickness in both directions X and Y were established. The results showed the usual characteristics dose uniformity as sample thickness decreased. The mean average absorbed dose on both sides at the surface and bottom of the samples for different thickness samples lead to establishing depth dose curve. Based on depth dose curve and operation conditions of electron beam machine, the process throughput for pasteurized oil palm EFB were estimated. (Author)

  16. ZnO nanowire-based glucose biosensors with different coupling agents

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Juneui [Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Lim, Sangwoo, E-mail: swlim@yonsei.ac.kr [Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749 (Korea, Republic of)

    2013-01-15

    Highlights: Black-Right-Pointing-Pointer Fabrication of ZnO nanowire-based glucose biosensors using different coupling agents. Black-Right-Pointing-Pointer Highest sensitivity for (3-aminopropyl)methyldiethoxysilane-treated biosensor. Black-Right-Pointing-Pointer Larger amount of glucose oxidase and lower electron transfer resistance for (3-aminopropyl)methyldiethoxysilane-treated biosensor. - Abstract: ZnO-nanowire-based glucose biosensors were fabricated by immobilizing glucose oxidase (GOx) onto a linker attached to ZnO nanowires. Different coupling agents were used, namely (3-aminopropyl)trimethoxysilane (APTMS), (3-aminopropyl)triethoxysilane (APTES), and (3-aminopropyl)methyldiethoxysilane (APS), to increase the affinity of GOx binding to ZnO nanowires. The amount of GOx immobilized on the ZnO nanowires, the performance, sensitivity, and Michaelis-Menten constant of each biosensor, and the electron transfer resistance through the biosensor were all measured in order to investigate the effect of the coupling agent on the ZnO nanowire-based biosensor. Among the different biosensors, the APS-treated biosensor had the highest sensitivity (17.72 {mu}A cm{sup -2} mM{sup -1}) and the lowest Michaelis-Menten constant (1.37 mM). Since APS-treated ZnO nanowires showed the largest number of C-N groups and the lowest electron transfer resistance through the biosensor, we concluded that these properties were the key factors in the performance of APS-treated glucose biosensors.

  17. ZnO nanowire-based glucose biosensors with different coupling agents

    International Nuclear Information System (INIS)

    Jung, Juneui; Lim, Sangwoo

    2013-01-01

    Highlights: ► Fabrication of ZnO nanowire-based glucose biosensors using different coupling agents. ► Highest sensitivity for (3-aminopropyl)methyldiethoxysilane-treated biosensor. ► Larger amount of glucose oxidase and lower electron transfer resistance for (3-aminopropyl)methyldiethoxysilane-treated biosensor. - Abstract: ZnO-nanowire-based glucose biosensors were fabricated by immobilizing glucose oxidase (GOx) onto a linker attached to ZnO nanowires. Different coupling agents were used, namely (3-aminopropyl)trimethoxysilane (APTMS), (3-aminopropyl)triethoxysilane (APTES), and (3-aminopropyl)methyldiethoxysilane (APS), to increase the affinity of GOx binding to ZnO nanowires. The amount of GOx immobilized on the ZnO nanowires, the performance, sensitivity, and Michaelis–Menten constant of each biosensor, and the electron transfer resistance through the biosensor were all measured in order to investigate the effect of the coupling agent on the ZnO nanowire-based biosensor. Among the different biosensors, the APS-treated biosensor had the highest sensitivity (17.72 μA cm −2 mM −1 ) and the lowest Michaelis–Menten constant (1.37 mM). Since APS-treated ZnO nanowires showed the largest number of C-N groups and the lowest electron transfer resistance through the biosensor, we concluded that these properties were the key factors in the performance of APS-treated glucose biosensors.

  18. Integrated self-powered microchip biosensor for endogenous biological cyanide.

    Science.gov (United States)

    Deng, Liu; Chen, Chaogui; Zhou, Ming; Guo, Shaojun; Wang, Erkang; Dong, Shaojun

    2010-05-15

    In this work we developed a fully integrated biofuel cell on a microchip, which consisted of glucose dehydrogenase supported (carbon nanotubes/thionine/gold nanoparticles)(8) multilayer as the anode, and the (carbon nanotubes/polylysine/laccase)(15) multilayer as the cathode. The as-obtained biofuel cell produced open circuit potential 620 mV and power density 302 microW cm(-2), showing great potential as a small power resource of portable electronics. Most importantly, for the first time we demonstrated the feasibility of developing a self-powered biosensor based on the inhibitive effect on microchip enzyme biofuel cell. With cyanide employed as the model analyte, this method showed a linear range of 3.0 x 10(-7) to 5.0 x 10(-4) M and a detection limit with 1.0 x 10(-7) M under the optimal conditions. The detection limit was lower than the acceptable cyanide concentration in drinking water (1.9 x 10(-6) M) according to the World Health Organization (WHO). This self-powered sensor was successfully used to detect the cyanide concentration in a real sample, cassava, which is the main carbohydrate resource in South America and Africa. This presented biosensor combined with a resistor and a multimeter demonstrated the general applicability as a fast and simple detection method in the determination of endogenous biological cyanide.

  19. Availability of Electronic Resources for Service Provision in ...

    African Journals Online (AJOL)

    The study also revealed that majority of the University libraries have adequate basic infrastructure for effective electronic information services. ... acquired by the library are put into maximal use by the library clientele, thereby ensuring the achievement of the library's objective which is satisfying the users, information needs.

  20. Utilization of bio-resources by low energy electron beam

    International Nuclear Information System (INIS)

    Kume, Tamikazu

    2003-01-01

    Utilization of bio-resources by radiation has been investigated for recycling the natural resources and reducing the environmental pollution. Polysaccharides such as chitosan and sodium alginate were easily degraded by irradiation and induced various kinds of biological activities, i.g. anti-microbial activity, promotion of plant growth, suppression of heavy metal stress, phytoalexins induction. Radiation degraded chitosan was effective to enhance the growth of plants in tissue culture. It was demonstrated that the liquid sample irradiation system using low energy EB was effective for the preparation of degraded polysaccharides. Methylcellulose (MC) can be crosslinked under certain radiation condition as same as carboxymethylcellulose (CMC) and produced the biodegradable hydrogel for medical and agricultural use. Treatment of soybean seeds by low energy EB enhanced the growth and the number of rhizobia on the root. (author)

  1. Acoustic biosensors.

    Science.gov (United States)

    Fogel, Ronen; Limson, Janice; Seshia, Ashwin A

    2016-06-30

    Resonant and acoustic wave devices have been researched for several decades for application in the gravimetric sensing of a variety of biological and chemical analytes. These devices operate by coupling the measurand (e.g. analyte adsorption) as a modulation in the physical properties of the acoustic wave (e.g. resonant frequency, acoustic velocity, dissipation) that can then be correlated with the amount of adsorbed analyte. These devices can also be miniaturized with advantages in terms of cost, size and scalability, as well as potential additional features including integration with microfluidics and electronics, scaled sensitivities associated with smaller dimensions and higher operational frequencies, the ability to multiplex detection across arrays of hundreds of devices embedded in a single chip, increased throughput and the ability to interrogate a wider range of modes including within the same device. Additionally, device fabrication is often compatible with semiconductor volume batch manufacturing techniques enabling cost scalability and a high degree of precision and reproducibility in the manufacturing process. Integration with microfluidics handling also enables suitable sample pre-processing/separation/purification/amplification steps that could improve selectivity and the overall signal-to-noise ratio. Three device types are reviewed here: (i) bulk acoustic wave sensors, (ii) surface acoustic wave sensors, and (iii) micro/nano-electromechanical system (MEMS/NEMS) sensors. © 2016 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  2. Analysis of Pedagogic Potential of Electronic Educational Resources with Elements of Autodidactics

    Directory of Open Access Journals (Sweden)

    Igor A.

    2018-03-01

    Full Text Available Introduction: in recent years didactic properties of electronic educational resources undergo considerable changes, nevertheless, the question of studying of such complete phenomenon as “an electronic educational resource with autodidactics elements” remains open, despite sufficient scientific base of researches of the terms making this concept. Article purpose – determination of essence of electronic educational resources with autodidactics elements. Materials and Methods: the main method of research was the theoretical analysis of the pedagogical and psychological literature on the problem under study. We used the theoretical (analysis, synthesis, comparison and generalization methods, the method of interpretation, pedagogical modeling, and empirical methods (observation, testing, conversation, interview, analysis of students’ performance, pedagogical experiment, peer review. Results: we detected the advantages of electronic educational resources in comparison with traditional ones. The concept of autodidactics as applied to the subject of research is considered. Properties of electronic educational resources with a linear and nonlinear principle of construction are studied.The influence of the principle of construction on the development of the learners’ qualities is shown. We formulated an integral definition of electronic educational resources with elements of autodidactics, namely, the variability, adaptivity and cyclicity of training. A model of the teaching-learning process with electronic educational resources is developed. Discussion and Conclusions: further development of a problem will allow to define whether electronic educational resources with autodidactics elements pedagogical potential for realization of educational and self-educational activity of teachers have, to modify technological procedures taking into account age features of students, their specialties and features of the organization of process of training of

  3. Design & fabrication of cantilever array biosensors

    DEFF Research Database (Denmark)

    Boisen, Anja; Thundat, T

    2009-01-01

    Surface immobilization of functional receptors on microfabricated cantilever arrays offers a new paradigm for the development of biosensors based on nanomechanics. Microcantilever-based systems are capable of real-time, multiplexed detection of unlabeled disease markers in extremely small volumes......, electronic processing, and even local telemetry on a single chip have the potential of satisfying the need for highly sensitive and selective multiple-target detection in very small samples. Here we will review the design and fabrication process of cantilever-based biosensors....

  4. A Study on Developing Evaluation Criteria for Electronic Resources in Evaluation Indicators of Libraries

    Science.gov (United States)

    Noh, Younghee

    2010-01-01

    This study aimed to improve the current state of electronic resource evaluation in libraries. While the use of Web DB, e-book, e-journal, and other e-resources such as CD-ROM, DVD, and micro materials is increasing in libraries, their use is not comprehensively factored into the general evaluation of libraries and may diminish the reliability of…

  5. Managing Selection for Electronic Resources: Kent State University Develops a New System to Automate Selection

    Science.gov (United States)

    Downey, Kay

    2012-01-01

    Kent State University has developed a centralized system that manages the communication and work related to the review and selection of commercially available electronic resources. It is an automated system that tracks the review process, provides selectors with price and trial information, and compiles reviewers' feedback about the resource. It…

  6. Where Do Electronic Books Fit in the College Research Arsenal of Resources?

    Science.gov (United States)

    Barbier, Patricia

    2007-01-01

    Student use of electronic books has become an accepted supplement to traditional resources. Student use and satisfaction was monitored through an online course discussion board. Increased use of electronic books indicate this service is an accepted supplement to the print book collection.

  7. BIOSENSORS FOR ENVIRONMENTAL APPLICATIONS

    Science.gov (United States)

    A review, with 19 references, is given on challenges and possible opportunities for the development of biosensors for environmental monitoring applications. The high cost and slow turnaround times typically associated with the measurement of regulated pollutants clearly indicates...

  8. Nanochannels Photoelectrochemical Biosensor.

    Science.gov (United States)

    Zhang, Nan; Ruan, Yi-Fan; Zhang, Li-Bin; Zhao, Wei-Wei; Xu, Jing-Juan; Chen, Hong-Yuan

    2018-02-06

    Nanochannels have brought new opportunities for biosensor development. Herein, we present the novel concept of a nanochannels photoelectrochemical (PEC) biosensor based on the integration of a unique Cu x O-nanopyramid-islands (NPIs) photocathode, an anodic aluminum oxide (AAO) membrane, and alkaline phosphatase (ALP) catalytic chemistry. The Cu x O-NPIs photocathode possesses good performance, and further assembly with AAO yields a designed architecture composed of vertically aligned, highly ordered nanoarrays on top of the Cu x O-NPIs film. After biocatalytic precipitation (BCP) was stimulated within the channels, the biosensor was used for the successful detection of ALP activity. This study has not only provided a novel paradigm for an unconventional nanochannels PEC biosensor, which can be used for general bioanalytical purposes, but also indicated that the new concept of nanochannel-semiconductor heterostructures is a step toward innovative biomedical applications.

  9. Triggered optical biosensor

    Science.gov (United States)

    Song, Xuedong; Swanson, Basil I.

    2001-10-02

    An optical biosensor is provided for the detection of a multivalent target biomolecule, the biosensor including a substrate having a bilayer membrane thereon, a recognition molecule situated at the surface, the recognition molecule capable of binding with the multivalent target biomolecule, the recognition molecule further characterized as including a fluorescence label thereon and as being movable at the surface and a device for measuring a fluorescence change in response to binding between the recognition molecule and the multivalent target biomolecule.

  10. Fabrication of Biosensors Based on Nanostructured Conducting Polyaniline (NSPANI

    Directory of Open Access Journals (Sweden)

    Deepshikha SAINI

    2011-11-01

    Full Text Available In this study, glucose and hydrogen peroxide (H2O2 biosensors based on nanostructured conducting polyaniline (NSPANI (synthesized using sodiumdodecyl sulphate (SDS as structure directing agent were developed. Because of the large specific surface area, excellent conductivity of NSPANI, horseradish peroxidase (HRP and glucose oxidase (GOx could be easily immobilized with high loading and activity. In addition the small dimensions and the high surface-to-volume ratio of the NSCP allow the rapid transmission of electron and enhance current response. The linear dynamic range of optical glucose and H2O2 biosensors is 5–40 mM for glucose and 1–50 mM for H2O2, respectively where as the bulk PANI exhibits linearity between 5-20 mM/l. The miniature optical glucose biosensor also exhibits good reproducibility. The storage stability of optical glucose and H2O2 biosensors is two weeks for glucose and five days for H2O2. The high response value of NSPANI based biosensors as compared to bulk PANI based biosensor reflects higher enzymatic affinity of GOx/NSPANI and HRP/NSPANI with glucose and H2O2 due to biocompatibility, active surface area and high electron communication capability of nanobiopolymer film. In conclusion, the NSPANI based biosensors proposed herein have many advantages such as a low response time, high reproducibility, high sensitivity, stable and wide dynamic range.

  11. The National Site Licensing of Electronic Resources: An Institutional Perspective

    Directory of Open Access Journals (Sweden)

    Xiaohua Zhu

    2011-06-01

    Full Text Available While academic libraries in most countries are struggling to negotiate with publishers and vendors individually or collaboratively via consortia, a few countries have experimented with a different model, national site licensing (NSL. Because NSL often involves government and large-scale collaboration, it has the potential to solve many problems in the complex licensing world. However, not many nations have adopted it. This study uses historical research approach and the comparative case study research method to explore the seemingly low level of adoption. The cases include the Canadian National Site Licensing Project (CNSLP, the United Kingdom’s National Electronic Site Licensing Initiative (NESLI, and the United States, which has not adopted NSL. The theoretical framework guiding the research design and data collection is W. Richard Scott’s institutional theory, which utilizes three supporting pillars—regulative, normative, and cultural-cognitive—to analyze institutional processes. In this study, the regulative pillar and the normative pillar of NSL adoption— an institutional construction and change—are examined. Data were collected from monographs, research articles, government documents, and relevant websites. Based on the analysis of these cases, a preliminary model is proposed for the adoption of NSL. The factors that support a country’s adoption of NSL include the need for new institutions, a centralized educational policy-making system and funding system, supportive political trends, and the tradition of cooperation. The factors that may prevent a country from adopting NSL include decentralized educational policy and funding, diversity and the large number of institutions, the concern for the “Big Deal,” and the concern for monopoly.

  12. Engineering prokaryotic transcriptional activators as metabolite biosensors in yeast

    DEFF Research Database (Denmark)

    Skjødt, Mette Louise; Snoek, Tim; Kildegaard, Kanchana Rueksomtawin

    2016-01-01

    ,cis-muconic acid at different levels, and found that reporter gene output correlated with production. The transplantation of prokaryotic transcriptional activators into the eukaryotic chassis illustrates the potential of a hitherto untapped biosensor resource useful for biotechnological applications....... real-time monitoring of production has attracted attention. Here we applied systematic engineering of multiple parameters to search for a general biosensor design in the budding yeast Saccharomyces cerevisiae based on small-molecule binding transcriptional activators from the prokaryote superfamily...

  13. Development and Applications of Portable Biosensors.

    Science.gov (United States)

    Srinivasan, Balaji; Tung, Steve

    2015-08-01

    The significance of microfluidics-based and microelectromechanical systems-based biosensors has been widely acknowledged, and many reviews have explored their potential applications in clinical diagnostics, personalized medicine, global health, drug discovery, food safety, and forensics. Because health care costs are increasing, there is an increasing need to remotely monitor the health condition of patients by point-of-care-testing. The demand for biosensors for detection of biological warfare agents has increased, and research is focused on ways of producing small portable devices that would allow fast, accurate, and on-site detection. In the past decade, the demand for rapid and accurate on-site detection of plant disease diagnosis has increased due to emerging pathogens with resistance to pesticides, increased human mobility, and regulations limiting the application of toxic chemicals to prevent spread of diseases. The portability of biosensors for on-site diagnosis is limited due to various issues, including sample preparation techniques, fluid-handling techniques, the limited lifetime of biological reagents, device packaging, integrating electronics for data collection/analysis, and the requirement of external accessories and power. Many microfluidic, electronic, and biological design strategies, such as handling liquids in biosensors without pumps/valves, the application of droplet-based microfluidics, paper-based microfluidic devices, and wireless networking capabilities for data transmission, are being explored. © 2015 Society for Laboratory Automation and Screening.

  14. Molecular Approaches to Optical Biosensors

    National Research Council Canada - National Science Library

    Fierke, Carol

    1998-01-01

    The goal of this proposal was to develop methodologies for the optimization of field-deployable optical biosensors, in general, and, in particular, to optimize a carbonic anhydrase-based fiber optic zinc biosensor...

  15. A survey of the use of electronic scientific information resources among medical and dental students

    Directory of Open Access Journals (Sweden)

    Aarnio Matti

    2006-05-01

    Full Text Available Abstract Background To evaluate medical and dental students' utilization of electronic information resources. Methods A web survey sent to 837 students (49.9% responded. Results Twenty-four per cent of medical students and ninteen per cent of dental students searched MEDLINE 2+ times/month for study purposes, and thiry-two per cent and twenty-four per cent respectively for research. Full-text articles were used 2+ times/month by thirty-three per cent of medical and ten per cent of dental students. Twelve per cent of respondents never utilized either MEDLINE or full-text articles. In multivariate models, the information-searching skills among students were significantly associated with use of MEDLINE and full-text articles. Conclusion Use of electronic resources differs among students. Forty percent were non-users of full-text articles. Information-searching skills are correlated with the use of electronic resources, but the level of basic PC skills plays not a major role in using these resources. The student data shows that adequate training in information-searching skills will increase the use of electronic information resources.

  16. Analytical Study of Usage of Electronic Information Resources at Pharmacopoeial Libraries in India

    Directory of Open Access Journals (Sweden)

    Sunil Tyagi

    2014-02-01

    Full Text Available The objective of this study is to know the rate and purpose of the use of e-resource by the scientists at pharmacopoeial libraries in India. Among other things, this study examined the preferences of the scientists toward printed books and journals, electronic information resources, and pattern of using e-resources. Non-probability sampling specially accidental and purposive technique was applied in the collection of primary data through administration of user questionnaire. The sample respondents chosen for the study consists of principle scientific officer, senior scientific officer, scientific officer, and scientific assistant of different division of the laboratories, namely, research and development, pharmaceutical chemistry, pharmacovigilance, pharmacology, pharmacogonosy, and microbiology. The findings of the study reveal the personal experiences and perceptions they have had on practice and research activity using e-resource. The major findings indicate that of the total anticipated participants, 78% indicated that they perceived the ability to use computer for electronic information resources. The data analysis shows that all the scientists belonging to the pharmacopoeial libraries used electronic information resources to address issues relating to drug indexes and compendia, monographs, drugs obtained through online databases, e-journals, and the Internet sources—especially polices by regulatory agencies, contacts, drug promotional literature, and standards.

  17. Photoelectrochemical enzymatic biosensors.

    Science.gov (United States)

    Zhao, Wei-Wei; Xu, Jing-Juan; Chen, Hong-Yuan

    2017-06-15

    Enzymatic biosensors have been valuable bioanalytical devices for analysis of diverse targets in disease diagnosis, biological and biomedical research, etc. Photoelectrochemical (PEC) bioanalysis is a recently emerged method that promptly becoming a subject of new research interests due to its attractive potential for future bioanalysis with high sensitivity and specificity. PEC enzymatic biosensors integrate the inherent sensitivities of PEC bioanalysis and the selectivity of enzymes and thus share their both advantages. Currently, PEC enzymatic biosensors have become a hot topic of significant research and the recent impetus has grown rapidly as demonstrated by increased research papers. Given the pace of advances in this area, this review will make a thorough discussion and survey on the fundamentals, sensing strategies, applications and the state of the art in PEC enzymatic biosensors, followed by future prospects based on our own opinions. We hope this work could provide an accessible introduction to PEC enzymatic biosensors for any scientist. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Considering Point-of-Care Electronic Medical Resources in Lieu of Traditional Textbooks for Medical Education.

    Science.gov (United States)

    Hale, LaDonna S; Wallace, Michelle M; Adams, Courtney R; Kaufman, Michelle L; Snyder, Courtney L

    2015-09-01

    Selecting resources to support didactic courses is a critical decision, and the advantages and disadvantages must be carefully considered. During clinical rotations, students not only need to possess strong background knowledge but also are expected to be proficient with the same evidence-based POC resources used by clinicians. Students place high value on “real world” learning and therefore may place more value on POC resources that they know practicing clinicians use as compared with medical textbooks. The condensed nature of PA education requires students to develop background knowledge and information literacy skills over a short period. One way to build that knowledge and those skills simultaneously is to use POC resources in lieu of traditional medical textbooks during didactic training. Electronic POC resources offer several advantages over traditional textbooks and should be considered as viable options in PA education.

  19. Elektronik Bilgi Kaynaklarının Seçimi / Selection of Electronic Information Resources

    Directory of Open Access Journals (Sweden)

    Pınar Al

    2003-04-01

    Full Text Available For many years, library users have used only from the printed media in order to get the information that they have needed. Today with the widespread use of the Web and the addition of electronic information resources to library collections, the use of information in the electronic environment as well as in printed media is started to be used. In time, such types of information resources as, electronic journals, electronic books, electronic encyclopedias, electronic dictionaries and electronic theses have been added to library collections. In this study, selection criteria that can be used for electronic information resources are discussed and suggestions are provided for libraries that try to select electronic information resources for their collections.

  20. Introduction to biosensors.

    Science.gov (United States)

    Bhalla, Nikhil; Jolly, Pawan; Formisano, Nello; Estrela, Pedro

    2016-06-30

    Biosensors are nowadays ubiquitous in biomedical diagnosis as well as a wide range of other areas such as point-of-care monitoring of treatment and disease progression, environmental monitoring, food control, drug discovery, forensics and biomedical research. A wide range of techniques can be used for the development of biosensors. Their coupling with high-affinity biomolecules allows the sensitive and selective detection of a range of analytes. We give a general introduction to biosensors and biosensing technologies, including a brief historical overview, introducing key developments in the field and illustrating the breadth of biomolecular sensing strategies and the expansion of nanotechnological approaches that are now available. © 2016 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  1. Biosensors in forensic sciences

    Directory of Open Access Journals (Sweden)

    Frederickx, C.

    2011-01-01

    Full Text Available A biosensor is a device that uses biological materials to detect and monitor the presence of specific chemicals in an area. Traditional methods of volatile detection used by law enforcement agencies and rescue teams typically consist of reliance on canine olfaction. This concept of using dogs to detect specific substances is quite old. However, dogs have some limitations such as cost of training and time of conditioning. Thus, the possibility of using other organisms as biosensors including rats, dolphins, honeybees, and parasitic wasps for detecting explosives, narcotics and cadavers has been developed. Insects have several advantages unshared by mammals. Insects are sensitive, cheap to produce and can be conditioned with impressive speed for a specific chemical-detection task. Moreover, insects might be a preferred sensing method in scenarios that are deemed too dangerous to use mammals. The purpose of this review is to provide an overview of the biosensors used in forensic sciences.

  2. Biosensors: Future Analytical Tools

    Directory of Open Access Journals (Sweden)

    Vikas

    2007-02-01

    Full Text Available Biosensors offer considerable promises for attaining the analytic information in a faster, simpler and cheaper manner compared to conventional assays. Biosensing approach is rapidly advancing and applications ranging from metabolite, biological/ chemical warfare agent, food pathogens and adulterant detection to genetic screening and programmed drug delivery have been demonstrated. Innovative efforts, coupling micromachining and nanofabrication may lead to even more powerful devices that would accelerate the realization of large-scale and routine screening. With gradual increase in commercialization a wide range of new biosensors are thus expected to reach the market in the coming years.

  3. Use of electronic sales data to tailor nutrition education resources for an ethnically diverse population.

    Science.gov (United States)

    Eyles, H; Rodgers, A; Ni Mhurchu, C

    2010-02-01

    Nutrition education may be most effective when personally tailored. Individualised electronic supermarket sales data offer opportunities to tailor nutrition education using shopper's usual food purchases. The present study aimed to use individualised electronic supermarket sales data to tailor nutrition resources for an ethnically diverse population in a large supermarket intervention trial in New Zealand. Culturally appropriate nutrition education resources (i.e. messages and shopping lists) were developed with the target population (through two sets of focus groups) and ethnic researchers. A nutrient database of supermarket products was developed using retrospective sales data and linked to participant sales to allow tailoring by usual food purchases. Modified Heart Foundation Tick criteria were used to identify 'healthier' products in the database suitable for promotion in the resources. Rules were developed to create a monthly report listing the tailored and culturally targeted messages to be sent to each participant, and to produce automated, tailored shopping lists. Culturally targeted nutrition messages (n = 864) and shopping lists (n = 3 formats) were developed. The food and nutrient database (n = 3000 top-selling products) was created using 12 months of retrospective sales data, and comprised 60%'healthier' products. Three months of baseline sales data were used to determine usual food purchases. Tailored resources were successfully mailed to 123 Māori, 52 Pacific and 346 non-Māori non-Pacific participants over the 6-month trial intervention period. Electronic supermarket sales data can be used to tailor nutrition education resources for a large number of ethnically diverse supermarket shoppers.

  4. Surface stress-based biosensors.

    Science.gov (United States)

    Sang, Shengbo; Zhao, Yuan; Zhang, Wendong; Li, Pengwei; Hu, Jie; Li, Gang

    2014-01-15

    Surface stress-based biosensors, as one kind of label-free biosensors, have attracted lots of attention in the process of information gathering and measurement for the biological, chemical and medical application with the development of technology and society. This kind of biosensors offers many advantages such as short response time (less than milliseconds) and a typical sensitivity at nanogram, picoliter, femtojoule and attomolar level. Furthermore, it simplifies sample preparation and testing procedures. In this work, progress made towards the use of surface stress-based biosensors for achieving better performance is critically reviewed, including our recent achievement, the optimally circular membrane-based biosensors and biosensor array. The further scientific and technological challenges in this field are also summarized. Critical remark and future steps towards the ultimate surface stress-based biosensors are addressed. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Electrochemical biosensors for hormone analyses.

    Science.gov (United States)

    Bahadır, Elif Burcu; Sezgintürk, Mustafa Kemal

    2015-06-15

    Electrochemical biosensors have a unique place in determination of hormones due to simplicity, sensitivity, portability and ease of operation. Unlike chromatographic techniques, electrochemical techniques used do not require pre-treatment. Electrochemical biosensors are based on amperometric, potentiometric, impedimetric, and conductometric principle. Amperometric technique is a commonly used one. Although electrochemical biosensors offer a great selectivity and sensitivity for early clinical analysis, the poor reproducible results, difficult regeneration steps remain primary challenges to the commercialization of these biosensors. This review summarizes electrochemical (amperometric, potentiometric, impedimetric and conductometric) biosensors for hormone detection for the first time in the literature. After a brief description of the hormones, the immobilization steps and analytical performance of these biosensors are summarized. Linear ranges, LODs, reproducibilities, regenerations of developed biosensors are compared. Future outlooks in this area are also discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. REVIEW OF MOODLE PLUGINS FOR DESIGNING MULTIMEDIA ELECTRONIC EDUCATIONAL RESOURCES FROM LANGUAGE DISCIPLINES

    Directory of Open Access Journals (Sweden)

    Anton M. Avramchuk

    2015-09-01

    Full Text Available Today the problem of designing multimedia electronic educational resources from language disciplines in Moodle is very important. This system has a lot of different, powerful resources, plugins to facilitate the learning of students with language disciplines. This article presents an overview and comparative analysis of the five Moodle plugins for designing multimedia electronic educational resources from language disciplines. There have been considered their key features and functionality in order to choose the best for studying language disciplines in the Moodle. Plugins are compared by a group of experts according to the criteria: efficiency, functionality and easy use. For a comparative analysis of the plugins it is used the analytic hierarchy process.

  7. Effects of the Use of Electronic Human Resource Management (EHRM Within Human Resource Management (HRM Functions at Universities

    Directory of Open Access Journals (Sweden)

    Chux Gervase Iwu

    2016-09-01

    Full Text Available This study set out to examine the effect of e-hrm systems in assisting human resource practitioners to execute their duties and responsibilities. In comparison to developed economies of the world, information technology adoption in sub-Saharan Africa has not been without certain glitches. Some of the factors that are responsible for these include poor need identification, sustainable funding, and insufficient skills. Besides these factors, there is also the issue of change management and users sticking to what they already know. Although, the above factors seem negative, there is strong evidence that information systems such as electronic human resource management present benefits to an organization. To achieve this, a dual research approach was utilized. Literature assisted immensely in both the development of the conceptual framework upon which the study hinged as well as in the development of the questionnaire items. The study also made use of an interview checklist to guide the participants. The findings reveal a mix of responses that indicate that while there are gains in adopting e-hrm systems, it is wiser to consider supporting resources as well as articulate the needs of the university better before any investment is made.

  8. The Electron Microscopy Outreach Program: A Web-based resource for research and education.

    Science.gov (United States)

    Sosinsky, G E; Baker, T S; Hand, G; Ellisman, M H

    1999-01-01

    We have developed a centralized World Wide Web (WWW)-based environment that serves as a resource of software tools and expertise for biological electron microscopy. A major focus is molecular electron microscopy, but the site also includes information and links on structural biology at all levels of resolution. This site serves to help integrate or link structural biology techniques in accordance with user needs. The WWW site, called the Electron Microscopy (EM) Outreach Program (URL: http://emoutreach.sdsc.edu), provides scientists with computational and educational tools for their research and edification. In particular, we have set up a centralized resource containing course notes, references, and links to image analysis and three-dimensional reconstruction software for investigators wanting to learn about EM techniques either within or outside of their fields of expertise. Copyright 1999 Academic Press.

  9. Identifying and evaluating electronic learning resources for use in adult-gerontology nurse practitioner education.

    Science.gov (United States)

    Thompson, Hilaire J; Belza, Basia; Baker, Margaret; Christianson, Phyllis; Doorenbos, Ardith; Nguyen, Huong

    2014-01-01

    Enhancing existing curricula to meet newly published adult-gerontology advanced practice registered nurse (APRN) competencies in an efficient manner presents a challenge to nurse educators. Incorporating shared, published electronic learning resources (ELRs) in existing or new courses may be appropriate in order to assist students in achieving competencies. The purposes of this project were to (a) identify relevant available ELR for use in enhancing geriatric APRN education and (b) to evaluate the educational utility of identified ELRs based on established criteria. A multilevel search strategy was used. Two independent team members reviewed identified ELR against established criteria to ensure utility. Only resources meeting all criteria were retained. Resources were found for each of the competency areas and included formats such as podcasts, Web casts, case studies, and teaching videos. In many cases, resources were identified using supplemental strategies and not through traditional search or search of existing geriatric repositories. Resources identified have been useful to advanced practice educators in improving lecture and seminar content in a particular topic area and providing students and preceptors with additional self-learning resources. Addressing sustainability within geriatric APRN education is critical for sharing of best practices among educators and for sustainability of teaching and related resources. © 2014.

  10. USE OF ELECTRONIC EDUCATIONAL RESOURCES WHEN TRAINING IN WORK WITH SPREADSHEETS

    Directory of Open Access Journals (Sweden)

    Х А Гербеков

    2017-12-01

    Full Text Available Today the tools for maintaining training courses based on opportunities of information and communication technologies are developed. Practically in all directions of preparation and on all subject matters electronic textbook and self-instruction manuals are created. Nevertheless the industry of computer educational and methodical materials actively develops and gets more and more areas of development and introduction. In this regard more and more urgent is a problem of development of the electronic educational resources adequate to modern educational requirements. Creation and the organization of training courses with use of electronic educational resources in particular on the basis of Internet technologies remains a difficult methodical task.In article the questions connected with development of electronic educational resources for use when studying the substantial line “Information technologies” of a school course of informatics in particular for studying of spreadsheets are considered. Also the analysis of maintenance of a school course and the unified state examination from the point of view of representation of task in him corresponding to the substantial line of studying “Information technologies” on mastering technology of information processing in spreadsheets and the methods of visualization given by means of charts and schedules is carried out.

  11. From Millennium ERM to Proquest 360 Resource Manager: Implementing a new Electronic Resources Management System ERMS in an International Graduate Research University in Saudi Arabia

    KAUST Repository

    Ramli, Rindra M.

    2017-01-01

    An overview of the Recommendation Study and the subsequent Implementation of a new Electronic Resources Management system ERMS in an international graduate research university in the Kingdom of Saudi Arabia. It covers the timeline, deliverables

  12. Availability, Level of Use and Constraints to Use of Electronic Resources by Law Lecturers in Public Universities in Nigeria

    Science.gov (United States)

    Amusa, Oyintola Isiaka; Atinmo, Morayo

    2016-01-01

    (Purpose) This study surveyed the level of availability, use and constraints to use of electronic resources among law lecturers in Nigeria. (Methodology) Five hundred and fifty-two law lecturers were surveyed and four hundred and forty-two responded. (Results) Data analysis revealed that the level of availability of electronic resources for the…

  13. GUIDELINES FOR EVALUATION OF PSYCHOLOGICAL AND PEDAGOGICAL QUALITY CHARACTERISTICS OF ELECTRONIC EDUCATIONAL RESOURCES

    Directory of Open Access Journals (Sweden)

    Galina P. Lavrentieva

    2014-05-01

    Full Text Available The article highlights the causes of insufficient effective use of electronic learning resources and sets out the guidelines on ways to solve the aforementioned problems. The set of didactic, methodical, psychological, pedagogical, design and ergonomic quality requirements is considered for evaluation, selection and application of information and communication technologies in the educational process. The most appropriate mechanisms for the ICT introduction into the learning process are disclosed as it should meet the specific learning needs of the student and the objectives of the educational process. The guidance for psycho-educational assessment of quality of electronic educational resources is provided. It is argued that the effectiveness of the ICT use is to be improved by means of quality evaluation mechanisms involved into the educational process.

  14. Model of e-learning with electronic educational resources of new generation

    OpenAIRE

    A. V. Loban; D. A. Lovtsov

    2017-01-01

    Purpose of the article: improving of scientific and methodical base of the theory of the е-learning of variability. Methods used: conceptual and logical modeling of the е-learning of variability process with electronic educational resource of new generation and system analysis of the interconnection of the studied subject area, methods, didactics approaches and information and communication technologies means. Results: the formalization complex model of the е-learning of variability with elec...

  15. Electrochemical biosensors in pharmaceutical analysis

    OpenAIRE

    Gil, Eric de Souza; Melo, Giselle Rodrigues de

    2010-01-01

    Given the increasing demand for practical and low-cost analytical techniques, biosensors have attracted attention for use in the quality analysis of drugs, medicines, and other analytes of interest in the pharmaceutical area. Biosensors allow quantification not only of the active component in pharmaceutical formulations, but also the analysis of degradation products and metabolites in biological fluids. Thus, this article presents a brief review of biosensor use in pharmaceutical analysis, fo...

  16. Design of nanostructured-based glucose biosensors

    Science.gov (United States)

    Komirisetty, Archana; Williams, Frances; Pradhan, Aswini; Konda, Rajini B.; Dondapati, Hareesh; Samantaray, Diptirani

    2012-04-01

    This paper presents the design of glucose sensors that will be integrated with advanced nano-materials, bio-coatings and electronics to create novel devices that are highly sensitive, inexpensive, accurate, and reliable. In the work presented, a glucose biosensor and its fabrication process flow have been designed. The device is based on electrochemical sensing using a working electrode with bio-functionalized zinc oxide (ZnO) nano-rods. Among all metal oxide nanostructures, ZnO nano-materials play a significant role as a sensing element in biosensors due to their properties such as high isoelectric point (IEP), fast electron transfer, non-toxicity, biocompatibility, and chemical stability which are very crucial parameters to achieve high sensitivity. Amperometric enzyme electrodes based on glucose oxidase (GOx) are used due to their stability and high selectivity to glucose. The device also consists of silicon dioxide and titanium layers as well as platinum working and counter electrodes and a silver/silver chloride reference electrode. Currently, the biosensors are being fabricated using the process flow developed. Once completed, the sensors will be bio-functionalized and tested to characterize their performance, including their sensitivity and stability.

  17. Novel amperometric glucose biosensor based on MXene nanocomposite

    KAUST Repository

    Rakhi, R. B.

    2016-11-10

    A biosensor platform based on Au/MXene nanocomposite for sensitive enzymatic glucose detection is reported. The biosensor leverages the unique electrocatalytic properties and synergistic effects between Au nanoparticles and MXene sheets. An amperometric glucose biosensor is fabricated by the immobilization of glucose oxidase (GOx) enzyme on Nafion solubilized Au/ MXene nanocomposite over glassy carbon electrode (GCE). The biomediated Au nanoparticles play a significant role in facilitating the electron exchange between the electroactive center of GOx and the electrode. The GOx/Au/MXene/Nafion/GCE biosensor electrode displayed a linear amperometric response in the glucose concentration range from 0.1 to 18 mM with a relatively high sensitivity of 4.2 μAmM−1 cm−2 and a detection limit of 5.9 μM (S/N = 3). Furthermore, the biosensor exhibited excellent stability, reproducibility and repeatability. Therefore, the Au/MXene nanocomposite reported in this work is a potential candidate as an electrochemical transducer in electrochemical biosensors.

  18. Novel amperometric glucose biosensor based on MXene nanocomposite

    KAUST Repository

    Baby, Rakhi Raghavan; Nayuk, Pranati; Xia, Chuan; Alshareef, Husam N.

    2016-01-01

    A biosensor platform based on Au/MXene nanocomposite for sensitive enzymatic glucose detection is reported. The biosensor leverages the unique electrocatalytic properties and synergistic effects between Au nanoparticles and MXene sheets. An amperometric glucose biosensor is fabricated by the immobilization of glucose oxidase (GOx) enzyme on Nafion solubilized Au/ MXene nanocomposite over glassy carbon electrode (GCE). The biomediated Au nanoparticles play a significant role in facilitating the electron exchange between the electroactive center of GOx and the electrode. The GOx/Au/MXene/Nafion/GCE biosensor electrode displayed a linear amperometric response in the glucose concentration range from 0.1 to 18 mM with a relatively high sensitivity of 4.2 μAmM−1 cm−2 and a detection limit of 5.9 μM (S/N = 3). Furthermore, the biosensor exhibited excellent stability, reproducibility and repeatability. Therefore, the Au/MXene nanocomposite reported in this work is a potential candidate as an electrochemical transducer in electrochemical biosensors.

  19. Designed graphene-peptide nanocomposites for biosensor applications: A review

    International Nuclear Information System (INIS)

    Wang, Li; Zhang, Yujie; Wu, Aiguo; Wei, Gang

    2017-01-01

    The modification of graphene with biomacromolecules like DNA, protein, peptide, and others extends the potential applications of graphene materials in various fields. The bound biomacromolecules could improve the biocompatibility and bio-recognition ability of graphene-based nanocomposites, therefore could greatly enhance their biosensing performances on both selectivity and sensitivity. In this review, we presented a comprehensive introduction and discussion on recent advance in the synthesis and biosensor applications of graphene-peptide nanocomposites. The biofunctionalization of graphene with specifically designed peptides, and the synthesis strategies of graphene-peptide (monomer, nanofibrils, and nanotubes) nanocomposites were demonstrated. On the other hand, the fabrication of graphene-peptide nanocomposite based biosensor architectures for electrochemical, fluorescent, electronic, and spectroscopic biosensing were further presented. This review includes nearly all the studies on the fabrication and applications of graphene-peptide based biosensors recently, which will promote the future developments of graphene-based biosensors in biomedical detection and environmental analysis. - Highlights: • A comprehensive review on the fabrication and application of graphene-peptide nanocomposites was presented. • The design of peptide sequences for biofunctionalization of various graphene materials was presented. • Multi-strategies on the fabrication of biosensors with graphene-peptide nanocomposites were discussed. • Designed graphene-peptide nanocomposites showed wide biosensor applications.

  20. A systematic review of portable electronic technology for health education in resource-limited settings.

    Science.gov (United States)

    McHenry, Megan S; Fischer, Lydia J; Chun, Yeona; Vreeman, Rachel C

    2017-08-01

    The objective of this study is to conduct a systematic review of the literature of how portable electronic technologies with offline functionality are perceived and used to provide health education in resource-limited settings. Three reviewers evaluated articles and performed a bibliography search to identify studies describing health education delivered by portable electronic device with offline functionality in low- or middle-income countries. Data extracted included: study population; study design and type of analysis; type of technology used; method of use; setting of technology use; impact on caregivers, patients, or overall health outcomes; and reported limitations. Searches yielded 5514 unique titles. Out of 75 critically reviewed full-text articles, 10 met inclusion criteria. Study locations included Botswana, Peru, Kenya, Thailand, Nigeria, India, Ghana, and Tanzania. Topics addressed included: development of healthcare worker training modules, clinical decision support tools, patient education tools, perceptions and usability of portable electronic technology, and comparisons of technologies and/or mobile applications. Studies primarily looked at the assessment of developed educational modules on trainee health knowledge, perceptions and usability of technology, and comparisons of technologies. Overall, studies reported positive results for portable electronic device-based health education, frequently reporting increased provider/patient knowledge, improved patient outcomes in both quality of care and management, increased provider comfort level with technology, and an environment characterized by increased levels of technology-based, informal learning situations. Negative assessments included high investment costs, lack of technical support, and fear of device theft. While the research is limited, portable electronic educational resources present promising avenues to increase access to effective health education in resource-limited settings, contingent

  1. Carbon nanotube biosensors

    Science.gov (United States)

    Tîlmaciu, Carmen-Mihaela; Morris, May C.

    2015-01-01

    Nanomaterials possess unique features which make them particularly attractive for biosensing applications. In particular, carbon nanotubes (CNTs) can serve as scaffolds for immobilization of biomolecules at their surface, and combine several exceptional physical, chemical, electrical, and optical characteristics properties which make them one of the best suited materials for the transduction of signals associated with the recognition of analytes, metabolites, or disease biomarkers. Here we provide a comprehensive review on these carbon nanostructures, in which we describe their structural and physical properties, functionalization and cellular uptake, biocompatibility, and toxicity issues. We further review historical developments in the field of biosensors, and describe the different types of biosensors which have been developed over time, with specific focus on CNT-conjugates engineered for biosensing applications, and in particular detection of cancer biomarkers. PMID:26579509

  2. Carbon Nanotube Biosensors

    Directory of Open Access Journals (Sweden)

    Carmen-Mihaela eTilmaciu

    2015-10-01

    Full Text Available Nanomaterials possess unique features which make them particularly attractive for biosensing applications. In particular Carbon Nanotubes (CNTs can serve as scaffolds for immobilization of biomolecules at their surface, and combine several exceptional physical, chemical, electrical and optical characteristics properties which make them one of the best suited materials for the transduction of signals associated with the recognition of analytes, metabolites or disease biomarkers. Here we provide a comprehensive review on these carbon nanostructures, in which we will describe their structural and physical properties, discuss functionalization and cellular uptake, biocompatibility and toxicity issues. We further review historical developments in the field of biosensors, and describe the different types of biosensors which have been developed over time, with specific focus on CNT-conjugates engineered for biosensing applications, and in particular detection of cancer biomarkers.

  3. Synthetic Electric Microbial Biosensors

    Science.gov (United States)

    2017-06-10

    domains and DNA-binding domains into a single protein for deregulation of down stream genes of have been favored [10]. Initially experiments with... Germany DISTRIBUTION A. Approved for public release: distribution unlimited.   Talk title: “Synthetic biology based microbial biosensors for the...toolbox” in Heidelberg, Germany Poster title: “Anaerobic whole cell microbial biosensors” Link: http://phdsymposium.embl.org/#home   September, 2014

  4. Model of e-learning with electronic educational resources of new generation

    Directory of Open Access Journals (Sweden)

    A. V. Loban

    2017-01-01

    Full Text Available Purpose of the article: improving of scientific and methodical base of the theory of the е-learning of variability. Methods used: conceptual and logical modeling of the е-learning of variability process with electronic educational resource of new generation and system analysis of the interconnection of the studied subject area, methods, didactics approaches and information and communication technologies means. Results: the formalization complex model of the е-learning of variability with electronic educational resource of new generation is developed, conditionally decomposed into three basic components: the formalization model of the course in the form of the thesaurusclassifier (“Author of e-resource”, the model of learning as management (“Coordination. Consultation. Control”, the learning model with the thesaurus-classifier (“Student”. Model “Author of e-resource” allows the student to achieve completeness, high degree of didactic elaboration and structuring of the studied material in triples of variants: modules of education information, practical task and control tasks; the result of the student’s (author’s of e-resource activity is the thesaurus-classifier. Model of learning as management is based on the principle of personal orientation of learning in computer environment and determines the logic of interaction between the lecturer and the student when determining the triple of variants individually for each student; organization of a dialogue between the lecturer and the student for consulting purposes; personal control of the student’s success (report generation and iterative search for the concept of the class assignment in the thesaurus-classifier before acquiring the required level of training. Model “Student” makes it possible to concretize the learning tasks in relation to the personality of the student and to the training level achieved; the assumption of the lecturer about the level of training of a

  5. Review of material recovery from used electric and electronic equipment-alternative options for resource conservation.

    Science.gov (United States)

    Friege, Henning

    2012-09-01

    For waste from electric and electronic equipment, the WEEE Directive stipulates the separate collection of electric and electronic waste. As to new electric and electronic devices, the Restriction of Hazardous Substances (RoHS) Directive bans the use of certain chemicals dangerous for man and environment. From the implementation of the WEEE directive, many unsolved problems have been documented: poor collection success, emission of dangerous substances during collection and recycling, irretrievable loss of valuable metals among others. As to RoHS, data from the literature show a satisfying success. The problems identified in the process can be reduced to some basic dilemmas at the borders between waste management, product policy and chemical safety. The objectives of the WEEE Directive and the specific targets for use and recycling of appliances are not consistent. There is no focus on scarce resources. Extended producer responsibility is not sufficient to guarantee sustainable waste management. Waste management reaches its limits due to problems of implementation but also due to physical laws. A holistic approach is necessary looking at all branch points and sinks in the stream of used products and waste from electric and electronic equipment. This may be done with respect to the general rules for sustainable management of material streams covering the three dimensions of sustainable policy. The relationships between the players in the field of electric and electronic devices have to be taken into account. Most of the problems identified in the implementation process will not be solved by the current amendment of the WEEE Directive.

  6. [Use of internet and electronic resources among Spanish intensivist physicians. First national survey].

    Science.gov (United States)

    Gómez-Tello, V; Latour-Pérez, J; Añón Elizalde, J M; Palencia-Herrejón, E; Díaz-Alersi, R; De Lucas-García, N

    2006-01-01

    Estimate knowledge and use habits of different electronic resources in a sample of Spanish intensivists: Internet, E-mail, distribution lists, and use of portable electronic devices. Self-applied questionnaire. A 50-question questionnaire was distributed among Spanish intensivists through the hospital marketing delegates of a pharmaceutical company and of electronic forums. A total of 682 questionnaires were analyzed (participation: 74%). Ninety six percent of those surveyed used Internet individually: 67% admitted training gap. Internet was the second source of clinical consultations most used (61%), slightly behind consultation to colleagues (65%). The pages consulted most were bibliographic databases (65%) and electronic professional journals (63%), with limited use of Evidence Based Medicine pages (19%). Ninety percent of those surveyed used e-mail regularly in the practice of their profession, although 25% admitted that were not aware of its possibilities. The use of E-mail decreased significantly with increase in age. A total of 62% of the intensivists used distribution lists. Of the rest, 42% were not aware of its existence and 32% admitted they had insufficient training to handle them. Twenty percent of those surveyed had portable electronic devices and 64% considered it useful, basically due to its rapid consultation at bedside. Female gender was a negative predictive factor of its use (OR 0.35; 95% CI 0.2-0.63; p=0.0002). A large majority of the Spanish intensivists use Internet and E-mail. E-mail lists and use of portable devices are still underused resources. There are important gaps in training and infrequent use of essential pages. There are specific groups that require directed educational policies.

  7. Protein Detection with Aptamer Biosensors

    Directory of Open Access Journals (Sweden)

    Regina Stoltenburg

    2008-07-01

    Full Text Available Aptamers have been developed for different applications. Their use as new biological recognition elements in biosensors promises progress for fast and easy detection of proteins. This new generation of biosensor (aptasensors will be more stable and well adapted to the conditions of real samples because of the specific properties of aptamers.

  8. Affinity biosensors: techniques and protocols

    National Research Council Canada - National Science Library

    Rogers, Kim R; Mulchandani, Ashok

    1998-01-01

    ..., and government to begin or expand their biosensors research. This volume, Methods in Biotechnology vol. 7: Affinity Biosensors: Techniques and Protocols, describes a variety of classical and emerging transduction technologies that have been interfaced to bioaffinity elements (e.g., antibodies and receptors). Some of the reas...

  9. A New Laccase Biosensor For Polyphenols Determination

    Directory of Open Access Journals (Sweden)

    M. J.F. Rebelo

    2003-06-01

    Full Text Available The relevance of polyphenols in human health is a well known fact. Prompted by that, a very intensive research has been directed to get a method to detect them, wich will improve the current ones. Laccase (p-diphenol:dioxygen oxidoreductase EC 1.10.3.2 is a multi-copper oxidase, wich couples catalytic oxidation of phenolic substrates with four electron reduction of dioxygen to water [1]. A maximum catalytic response in oxigenated electrolyte was observed between 4.5 and 5.5 [2], while for pH > 6.9 the laccase was found to be inactive [3]. We prepared a biosensor with laccase immobilised on a polyether sulphone membrane, at pH 4.5, wich was applied at Universal Sensors base electrode. Reduction of the product of oxidation of several polyphenols, catalysed by laccase, was done at a potential for wich the polyphenol of interest was found to respond. Reduction of catechol was found to occur at a potential of -200mV, wich is often referred to in the literature for polyphenolic biosensors. However other polyphenols did not respond at that potential. It was observed that (+- catechin produced a very large cathodic current when +100mV were applied to the laccase biosensor, both in aqueous acetate and 12% ethanol acetate buffer, whereas caffeic acid responded at -50mV. Other polyphenols tested were gallic acid, malvidin, quercetin, rutin, trans-resveratrol

  10. The Synthesis of the Hierarchical Structure of Information Resources for Management of Electronic Commerce Entities

    Directory of Open Access Journals (Sweden)

    Krutova Anzhelika S.

    2017-06-01

    Full Text Available The aim of the article is to develop the theoretical bases for the classification and coding of economic information and the scientific justification of the content of information resources of an electronic commerce enterprise. The essence of information resources for management of electronic business entities is investigated. It is proved that the organization of accounting in e-commerce systems is advisable to be built on the basis of two circuits: accounting for financial flows and accounting associated with transformation of business factors in products and services as a result of production activities. There presented a sequence of accounting organization that allows to combine the both circuits in a single information system, which provides a possibility for the integrated replenishment and distributed simultaneous use of the e-commerce system by all groups of users. It is proved that the guarantee of efficient activity of the information management system of electronic commerce entities is a proper systematization of the aggregate of information resources on economic facts and operations of an enterprise in accordance with the management tasks by building the hierarchy of accounting nomenclatures. It is suggested to understand nomenclature as an objective, primary information aggregate concerning a certain fact of the economic activity of an enterprise, which is characterized by minimum requisites, is entered into the database of the information system and is to be reflected in the accounting system. It is proposed to build a database of e-commerce systems as a part of directories (constants, personnel, goods / products, suppliers, buyers and the hierarchy of accounting nomenclatures. The package of documents regulating the organization of accounting at an enterprise should include: the provision on the accounting services, the order on the accounting policy, the job descriptions, the schedules of information exchange, the report card and

  11. ELECTRONIC EDUCATIONAL RESOURCES FOR ONLINE SUPPORT OF MODERN CHEMISTRY CLASSES IN SPECIALIZED SCHOOL

    Directory of Open Access Journals (Sweden)

    Maria D. Tukalo

    2013-09-01

    Full Text Available This article contains material of some modern electronic educational resources that can be used via the Internet to support the modern chemistry classes in specialized school. It was drawn attention to the educational chemical experiments as means of knowledge; simulated key motivational characteristics to enhance students interest for learning subjects, their cognitive and practical activity in the formation of self-reliance and self-creative; commented forecasts for creating of conditions to enhance the creative potential of students in a modern learning environment.

  12. THE MODEL OF LINGUISTIC TEACHERS’ COMPETENCY DEVELOPMENT ON DESIGNING MULTIMEDIA ELECTRONIC EDUCATIONAL RESOURCES IN THE MOODLE SYSTEM

    Directory of Open Access Journals (Sweden)

    Anton M. Avramchuk

    2017-10-01

    Full Text Available The article is devoted to the problem of developing the competency of teachers of language disciplines on designing multimedia electronic educational resources in the Moodle system. The concept of "the competence of teachers of language disciplines on designing multimedia electronic educational resources in the Moodle system" is justified and defined. Identified and characterized the components by which the levels of the competency development of teachers of language disciplines on designing multimedia electronic educational resources in the Moodle system should be assessed. Developed a model for the development of the competency of teachers of language disciplines on designing multimedia electronic educational resources in the Moodle system, which is based on the main scientific approaches, used in adult education, and consists of five blocks: target, informative, technological, diagnostic and effective.

  13. A preliminary categorization of end-of-life electrical and electronic equipment as secondary metal resources

    International Nuclear Information System (INIS)

    Oguchi, Masahiro; Murakami, Shinsuke; Sakanakura, Hirofumi; Kida, Akiko; Kameya, Takashi

    2011-01-01

    Highlights: → End-of-life electrical and electronic equipment (EEE) as secondary metal resources. → The content and the total amount of metals in specific equipment are both important. → We categorized 21 EEE types from contents and total amounts of various metals. → Important equipment types as secondary resources were listed for each metal kind. → Collectability and possible collection systems of various EEE types were discussed. - Abstract: End-of-life electrical and electronic equipment (EEE) has recently received attention as a secondary source of metals. This study examined characteristics of end-of-life EEE as secondary metal resources to consider efficient collection and metal recovery systems according to the specific metals and types of EEE. We constructed an analogy between natural resource development and metal recovery from end-of-life EEE and found that metal content and total annual amount of metal contained in each type of end-of-life EEE should be considered in secondary resource development, as well as the collectability of the end-of-life products. We then categorized 21 EEE types into five groups and discussed their potential as secondary metal resources. Refrigerators, washing machines, air conditioners, and CRT TVs were evaluated as the most important sources of common metals, and personal computers, mobile phones, and video games were evaluated as the most important sources of precious metals. Several types of small digital equipment were also identified as important sources of precious metals; however, mid-size information and communication technology (ICT) equipment (e.g., printers and fax machines) and audio/video equipment were shown to be more important as a source of a variety of less common metals. The physical collectability of each type of EEE was roughly characterized by unit size and number of end-of-life products generated annually. Current collection systems in Japan were examined and potentially appropriate collection

  14. Open-Source Electronic Health Record Systems for Low-Resource Settings: Systematic Review.

    Science.gov (United States)

    Syzdykova, Assel; Malta, André; Zolfo, Maria; Diro, Ermias; Oliveira, José Luis

    2017-11-13

    Despite the great impact of information and communication technologies on clinical practice and on the quality of health services, this trend has been almost exclusive to developed countries, whereas countries with poor resources suffer from many economic and social issues that have hindered the real benefits of electronic health (eHealth) tools. As a component of eHealth systems, electronic health records (EHRs) play a fundamental role in patient management and effective medical care services. Thus, the adoption of EHRs in regions with a lack of infrastructure, untrained staff, and ill-equipped health care providers is an important task. However, the main barrier to adopting EHR software in low- and middle-income countries is the cost of its purchase and maintenance, which highlights the open-source approach as a good solution for these underserved areas. The aim of this study was to conduct a systematic review of open-source EHR systems based on the requirements and limitations of low-resource settings. First, we reviewed existing literature on the comparison of available open-source solutions. In close collaboration with the University of Gondar Hospital, Ethiopia, we identified common limitations in poor resource environments and also the main requirements that EHRs should support. Then, we extensively evaluated the current open-source EHR solutions, discussing their strengths and weaknesses, and their appropriateness to fulfill a predefined set of features relevant for low-resource settings. The evaluation methodology allowed assessment of several key aspects of available solutions that are as follows: (1) integrated applications, (2) configurable reports, (3) custom reports, (4) custom forms, (5) interoperability, (6) coding systems, (7) authentication methods, (8) patient portal, (9) access control model, (10) cryptographic features, (11) flexible data model, (12) offline support, (13) native client, (14) Web client,(15) other clients, (16) code

  15. Redox-flexible NADH oxidase biosensor: A platform for various dehydrogenase bioassays and biosensors

    International Nuclear Information System (INIS)

    Serban, Simona; El Murr, Nabil

    2006-01-01

    A generic amperometric bioassay based on the enzymatic oxidation catalysed by the stable NADH oxidase (NAox) from Thermus thermophilus has been developed for NADH measurements. The NAox uses O 2 as its natural electron acceptor and produces H 2 O 2 in a two-electron process. Electrochemical and spectrophotometric experiments showed that the NAox used in this work, presents a very good activity towards its substrate and, in contrary to previously mentioned NADH oxidases, does not require the addition of any exogenous flavin cofactor neither to promote nor to maintain its activity. In addition, the NAox used also works with artificial electron acceptors like ferrocene derivatives. O 2 was successfully replaced by redox mediators such as hydroxymethyl ferrocene (FcCH 2 OH) for the regeneration of the active enzyme. Combining the NAox with the mediator and the horseradish peroxidase we developed an original, high sensitive 'redox-flexible' NADH amperometric bioassay working in a large window of applied potentials in both oxidation and reduction modes. The biosensor has a continuous and complementary linearity range permitting to measure NADH concentrations starting from 5 x 10 -6 M in reduction until 2 x 10 3 M in oxidation. This redox-flexibility allows choosing the applied potential in order to avoid electrochemical interferences. The association of the 'redox-flexible' concept with NADH dependent enzymes opens a novel strategy for dehydrogenases based bioassays and biosensors. The great number of dehydrogenases available makes the concept applicable for numerous substrates to analyse. Moreover it allows the development of a wide range of biosensors on the basis of a generic platform. This gives several advantages over the previous manufacturing techniques and offers a general and flexible scheme for the fabrication of biosensors presenting high sensitivities, wide calibration ranges and less affected by electrochemical interferences

  16. THE MODEL OF LINGUISTIC TEACHERS’ COMPETENCY DEVELOPMENT ON DESIGNING MULTIMEDIA ELECTRONIC EDUCATIONAL RESOURCES IN THE MOODLE SYSTEM

    OpenAIRE

    Anton M. Avramchuk

    2017-01-01

    The article is devoted to the problem of developing the competency of teachers of language disciplines on designing multimedia electronic educational resources in the Moodle system. The concept of "the competence of teachers of language disciplines on designing multimedia electronic educational resources in the Moodle system" is justified and defined. Identified and characterized the components by which the levels of the competency development of teachers of language disciplines on designing ...

  17. Determining the level of awareness of the physicians in using the variety of electronic information resources and the effecting factors.

    Science.gov (United States)

    Papi, Ahmad; Ghazavi, Roghayeh; Moradi, Salimeh

    2015-01-01

    Understanding of the medical society's from the types of information resources for quick and easy access to information is an imperative task in medical researches and management of the treatment. The present study was aimed to determine the level of awareness of the physicians in using various electronic information resources and the factors affecting it. This study was a descriptive survey. The data collection tool was a researcher-made questionnaire. The study population included all the physicians and specialty physicians of the teaching hospitals affiliated to Isfahan University of Medical Sciences and numbered 350. The sample size based on Morgan's formula was set at 180. The content validity of the tool was confirmed by the library and information professionals and the reliability was 95%. Descriptive statistics were used including the SPSS software version 19. On reviewing the need of the physicians to obtain the information on several occasions, the need for information in conducting the researches was reported by the maximum number of physicians (91.9%) and the usage of information resources, especially the electronic resources, formed 65.4% as the highest rate with regard to meeting the information needs of the physicians. Among the electronic information databases, the maximum awareness was related to Medline with 86.5%. Among the various electronic information resources, the highest awareness (43.3%) was related to the E-journals. The highest usage (36%) was also from the same source. The studied physicians considered the most effective deterrent in the use of electronic information resources as being too busy and lack of time. Despite the importance of electronic information resources for the physician's community, there was no comprehensive knowledge of these resources. This can lead to less usage of these resources. Therefore, careful planning is necessary in the hospital libraries in order to introduce the facilities and full capabilities of the

  18. A reduced graphene oxide based electrochemical biosensor for tyrosine detection

    Science.gov (United States)

    Wei, Junhua; Qiu, Jingjing; Li, Li; Ren, Liqiang; Zhang, Xianwen; Chaudhuri, Jharna; Wang, Shiren

    2012-08-01

    In this paper, a ‘green’ and safe hydrothermal method has been used to reduce graphene oxide and produce hemin modified graphene nanosheet (HGN) based electrochemical biosensors for the determination of l-tyrosine levels. The as-fabricated HGN biosensors were characterized by UV-visible absorption spectra, fluorescence spectra, Fourier transform infrared spectroscopy (FTIR) spectra and thermogravimetric analysis (TGA). The experimental results indicated that hemin was successfully immobilized on the reduced graphene oxide nanosheet (rGO) through π-π interaction. TEM images and EDX results further confirmed the attachment of hemin on the rGO nanosheet. Cyclic voltammetry tests were carried out for the bare glass carbon electrode (GCE), the rGO electrode (rGO/GCE), and the hemin-rGO electrode (HGN/GCE). The HGN/GCE based biosensor exhibits a tyrosine detection linear range from 5 × 10-7 M to 2 × 10-5 M with a detection limitation of 7.5 × 10-8 M at a signal-to-noise ratio of 3. The sensitivity of this biosensor is 133 times higher than that of the bare GCE. In comparison with other works, electroactive biosensors are easily fabricated, easily controlled and cost-effective. Moreover, the hemin-rGO based biosensors demonstrate higher stability, a broader detection linear range and better detection sensitivity. Study of the oxidation scheme reveals that the rGO enhances the electron transfer between the electrode and the hemin, and the existence of hemin groups effectively electrocatalyzes the oxidation of tyrosine. This study contributes to a widespread clinical application of nanomaterial based biosensor devices with a broader detection linear range, improved stability, enhanced sensitivity and reduced costs.

  19. Success criteria for electronic medical record implementations in low-resource settings: a systematic review.

    Science.gov (United States)

    Fritz, Fleur; Tilahun, Binyam; Dugas, Martin

    2015-03-01

    Electronic medical record (EMR) systems have the potential of supporting clinical work by providing the right information at the right time to the right people and thus make efficient use of resources. This is especially important in low-resource settings where reliable data are also needed to support public health and local supporting organizations. In this systematic literature review, our objectives are to identify and collect literature about success criteria of EMR implementations in low-resource settings and to summarize them into recommendations. Our search strategy relied on PubMed queries and manual bibliography reviews. Studies were included if EMR implementations in low-resource settings were described. The extracted success criteria and measurements were summarized into 7 categories: ethical, financial, functionality, organizational, political, technical, and training. We collected 381 success criteria with 229 measurements from 47 articles out of 223 articles. Most papers were evaluations or lessons learned from African countries, published from 1999 to 2013. Almost half of the EMR systems served a specific disease area like human immunodeficiency virus (HIV). The majority of criteria that were reported dealt with the functionality, followed by organizational issues, and technical infrastructures. Sufficient training and skilled personnel were mentioned in roughly 10%. Political, ethical, and financial considerations did not play a predominant role. More evaluations based on reliable frameworks are needed. Highly reliable data handling methods, human resources and effective project management, as well as technical architecture and infrastructure are all key factors for successful EMR implementation. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Impact of Knowledge Resources Linked to an Electronic Health Record on Frequency of Unnecessary Tests and Treatments

    Science.gov (United States)

    Goodman, Kenneth; Grad, Roland; Pluye, Pierre; Nowacki, Amy; Hickner, John

    2012-01-01

    Introduction: Electronic knowledge resources have the potential to rapidly provide answers to clinicians' questions. We sought to determine clinicians' reasons for searching these resources, the rate of finding relevant information, and the perceived clinical impact of the information they retrieved. Methods: We asked general internists, family…

  1. Microbial biosensors for environmental monitoring

    Directory of Open Access Journals (Sweden)

    David VOGRINC

    2015-12-01

    Full Text Available Microbial biosensors are analytical devices capable of sensing substances in the environment due to the specific biological reaction of the microorganism or its parts. Construction of a microbial biosensor requires knowledge of microbial response to the specific analyte. Linking this response with the quantitative data, using a transducer, is the crucial step in the construction of a biosensor. Regarding the transducer type, biosensors are divided into electrochemical, optical biosensors and microbial fuel cells. The use of the proper configuration depends on the selection of the biosensing element. With the use of transgenic E. coli strains, bioluminescence or fluorescence based biosensors were developed. Microbial fuel cells enable the use of the heterogeneous microbial populations, isolated from wastewater. Different microorganisms are used for different pollutants – pesticides, heavy metals, phenolic compounds, organic waste, etc. Biosensing enables measurement of their concentration and their toxic or genotoxic effects on the microbes. Increasing environmental awareness has contributed to the increase of interest for biomonitoring. Although technologies, such as bioinformatics and genetic engineering, allow us to design complex and efficient microbial biosensors for environmental pollutants, the transfer of the laboratory work to the field still remains a problem to solve.

  2. Recent advances in ZnO nanostructures and thin films for biosensor applications: Review

    International Nuclear Information System (INIS)

    Arya, Sunil K.; Saha, Shibu; Ramirez-Vick, Jaime E.; Gupta, Vinay; Bhansali, Shekhar; Singh, Surinder P.

    2012-01-01

    Graphical abstract: ZnO nanostructures have shown binding of biomolecules in desired orientation with improved conformation and high biological activity, resulting in enhanced sensing characteristics. Furthermore, their compatibility with complementary metal oxide semiconductor technology for constructing integrated circuits makes them suitable candidate for future small integrated biosensor devices. This review highlights various approaches to synthesize ZnO nanostructures and thin films, and their applications in biosensor technology. Highlights: ► This review highlights various approaches to synthesize ZnO nanostructures and thin films. ► Article highlights the importance of ZnO nanostructures as biosensor matrix. ► Article highlights the advances in various biosensors based on ZnO nanostructures. ► Article describes the potential of ZnO based biosensor for new generation healthcare devices. - Abstract: Biosensors have shown great potential for health care and environmental monitoring. The performance of biosensors depends on their components, among which the matrix material, i.e., the layer between the recognition layer of biomolecule and transducer, plays a crucial role in defining the stability, sensitivity and shelf-life of a biosensor. Recently, zinc oxide (ZnO) nanostructures and thin films have attracted much interest as materials for biosensors due to their biocompatibility, chemical stability, high isoelectric point, electrochemical activity, high electron mobility, ease of synthesis by diverse methods and high surface-to-volume ratio. ZnO nanostructures have shown the binding of biomolecules in desired orientations with improved conformation and high biological activity, resulting in enhanced sensing characteristics. Furthermore, compatibility with complementary metal oxide semiconductor technology for constructing integrated circuits makes ZnO nanostructures suitable candidate for future small integrated biosensor devices. This review

  3. Recent advances in ZnO nanostructures and thin films for biosensor applications: Review

    Energy Technology Data Exchange (ETDEWEB)

    Arya, Sunil K., E-mail: sunilarya333@gmail.com [Bioelectronics Program, Institute of Microelectronics, A-Star 11 Science Park Road, Singapore Science Park II, Singapore 117685 (Singapore); Saha, Shibu [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Ramirez-Vick, Jaime E. [Engineering Science and Materials Department, University of Puerto Rico, Mayaguez, PR 00681 (United States); Gupta, Vinay [Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Bhansali, Shekhar [Department of Electrical and Computer Engineering, Florida International University, Miami, FL (United States); Singh, Surinder P., E-mail: singh.uprm@gmail.com [National Physical Laboratory, Dr K.S. Krishnan Marg, New Delhi 110012 (India)

    2012-08-06

    Graphical abstract: ZnO nanostructures have shown binding of biomolecules in desired orientation with improved conformation and high biological activity, resulting in enhanced sensing characteristics. Furthermore, their compatibility with complementary metal oxide semiconductor technology for constructing integrated circuits makes them suitable candidate for future small integrated biosensor devices. This review highlights various approaches to synthesize ZnO nanostructures and thin films, and their applications in biosensor technology. Highlights: Black-Right-Pointing-Pointer This review highlights various approaches to synthesize ZnO nanostructures and thin films. Black-Right-Pointing-Pointer Article highlights the importance of ZnO nanostructures as biosensor matrix. Black-Right-Pointing-Pointer Article highlights the advances in various biosensors based on ZnO nanostructures. Black-Right-Pointing-Pointer Article describes the potential of ZnO based biosensor for new generation healthcare devices. - Abstract: Biosensors have shown great potential for health care and environmental monitoring. The performance of biosensors depends on their components, among which the matrix material, i.e., the layer between the recognition layer of biomolecule and transducer, plays a crucial role in defining the stability, sensitivity and shelf-life of a biosensor. Recently, zinc oxide (ZnO) nanostructures and thin films have attracted much interest as materials for biosensors due to their biocompatibility, chemical stability, high isoelectric point, electrochemical activity, high electron mobility, ease of synthesis by diverse methods and high surface-to-volume ratio. ZnO nanostructures have shown the binding of biomolecules in desired orientations with improved conformation and high biological activity, resulting in enhanced sensing characteristics. Furthermore, compatibility with complementary metal oxide semiconductor technology for constructing integrated circuits makes Zn

  4. Resource conservation approached with an appropriate collection and upgrade-remanufacturing for used electronic products.

    Science.gov (United States)

    Zlamparet, Gabriel I; Tan, Quanyin; Stevels, A B; Li, Jinhui

    2018-03-01

    This comparative research represents an example for a better conservation of resources by reducing the amount of waste (kg) and providing it more value under the umbrella of remanufacturing. The three discussed cases will expose three issues already addressed separately in the literature. The generation of waste electrical and electronic equipment (WEEE) interacts with the environmental depletion. In this article, we gave the examples of addressed issues under the concept of remanufacturing. Online collection opportunity eliminating classical collection, a business to business (B2B) implementation for remanufactured servers and medical devices. The material reuse (recycling), component sustainability, reuse (part harvesting), product reuse (after repair/remanufacturing) indicates the recovery potential using remanufacturing tool for a better conservation of resources adding more value to the products. Our findings can provide an overview of new system organization for the general collection, market potential and the technological advantages using remanufacturing instead of recycling of WEEE or used electrical and electronic equipment. Copyright © 2017. Published by Elsevier Ltd.

  5. Recent advances in electrochemical biosensors based on graphene two-dimensional nanomaterials.

    Science.gov (United States)

    Song, Yang; Luo, Yanan; Zhu, Chengzhou; Li, He; Du, Dan; Lin, Yuehe

    2016-02-15

    Graphene as a star among two-dimensional nanomaterials has attracted tremendous research interest in the field of electrochemistry due to their intrinsic properties, including the electronic, optical, and mechanical properties associated with their planar structure. The marriage of graphene and electrochemical biosensors has created many ingenious biosensing strategies for applications in the areas of clinical diagnosis and food safety. This review provides a comprehensive overview of the recent advances in the development of graphene based electrochemical biosensors. Special attention is paid to graphene-based enzyme biosensors, immunosensors, and DNA biosensors. Future perspectives on high-performance graphene-based electrochemical biosensors are also discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Improved Biosensors for Soils

    Science.gov (United States)

    Silberg, J. J.; Masiello, C. A.; Cheng, H. Y.

    2014-12-01

    Microbes drive processes in the Earth system far exceeding their physical scale, affecting crop yields, water quality, the mobilization of toxic materials, and fundamental aspects of soil biogeochemistry. The tools of synthetic biology have the potential to significantly improve our understanding of microbial Earth system processes: for example, synthetic microbes can be be programmed to report on environmental conditions that stimulate greenhouse gas production, metal oxidation, biofilm formation, pollutant degradation, and microbe-plant symbioses. However, these tools are only rarely deployed in the lab. This research gap arises because synthetically programmed microbes typically report on their environment by producing molecules that are detected optically (e.g., fluorescent proteins). Fluorescent reporters are ideal for petri-dish applications and have fundamentally changed how we study human health, but their usefulness is quite limited in soils where detecting fluorescence is challenging. Here we describe the construction of gas-reporting biosensors, which release nonpolar gases that can be detected in the headspace of incubation experiments. These constructs can be used to probe microbial processes within soils in real-time noninvasive lab experiments. These biosensors can be combined with traditional omics-based approaches to reveal processes controlling soil microbial behavior and lead to improved environmental management decisions.

  7. Biosensors based on cantilevers.

    Science.gov (United States)

    Alvarez, Mar; Carrascosa, Laura G; Zinoviev, Kiril; Plaza, Jose A; Lechuga, Laura M

    2009-01-01

    Microcantilevers based-biosensors are a new label-free technique that allows the direct detection of biomolecular interactions in a label-less way and with great accuracy by translating the biointeraction into a nanomechanical motion. Low cost and reliable standard silicon technologies are widely used for the fabrication of cantilevers with well-controlled mechanical properties. Over the last years, the number of applications of these sensors has shown a fast growth in diverse fields, such as genomic or proteomic, because of the biosensor flexibility, the low sample consumption, and the non-pretreated samples required. In this chapter, we report a dedicated design and a fabrication process of highly sensitive microcantilever silicon sensors. We will describe as well an application of the device in the environmental field showing the immunodetection of an organic toxic pesticide as an example. The cantilever biofunctionalization process and the subsequent pesticide determination are detected in real time by monitoring the nanometer-scale bending of the microcantilever due to a differential surface stress generated between both surfaces of the device.

  8. Guided-Wave Optical Biosensors

    Science.gov (United States)

    Passaro, Vittorio M. N.; Dell'Olio, Francesco; Casamassima, Biagio; De Leonardis, Francesco

    2007-01-01

    Guided-wave optical biosensors are reviewed in this paper. Advantages related to optical technologies are presented and integrated architectures are investigated in detail. Main classes of bio receptors and the most attractive optical transduction mechanisms are discussed. The possibility to use Mach-Zehnder and Young interferometers, microdisk and microring resonators, surface plasmon resonance, hollow and antiresonant waveguides, and Bragg gratings to realize very sensitive and selective, ultra-compact and fast biosensors is discussed. Finally, CMOS-compatible technologies are proved to be the most attractive for fabrication of guided-wave photonic biosensors.

  9. Electronic theses and dissertations: a review of this valuable resource for nurse scholars worldwide.

    Science.gov (United States)

    Goodfellow, L M

    2009-06-01

    A worldwide repository of electronic theses and dissertations (ETDs) could provide worldwide access to the most up-to-date research generated by masters and doctoral students. Until that international repository is established, it is possible to access some of these valuable knowledge resources. ETDs provide a technologically advanced medium with endless multimedia capabilities that far exceed the print and bound copies of theses and dissertations housed traditionally in individual university libraries. CURRENT USE: A growing trend exists for universities worldwide to require graduate students to submit theses or dissertations as electronic documents. However, nurse scholars underutilize ETDs, as evidenced by perusing bibliographic citation lists in many of the research journals. ETDs can be searched for and retrieved through several digital resources such as the Networked Digital Library of Theses and Dissertations (http://www.ndltd.org), ProQuest Dissertations and Theses (http://www.umi.com), the Australasian Digital Theses Program (http://adt.caul.edu.au/) and through individual university web sites and online catalogues. An international repository of ETDs benefits the community of nurse scholars in many ways. The ability to access recent graduate students' research electronically from anywhere in the world is advantageous. For scholars residing in developing countries, access to these ETDs may prove to be even more valuable. In some cases, ETDs are not available for worldwide access and can only be accessed through the university library from which the student graduated. Public access to university library ETD collections is not always permitted. Nurse scholars from both developing and developed countries could benefit from ETDs.

  10. Tin Oxide Nanorod Array-Based Electrochemical Hydrogen Peroxide Biosensor

    Directory of Open Access Journals (Sweden)

    Liu Jinping

    2010-01-01

    Full Text Available Abstract SnO2 nanorod array grown directly on alloy substrate has been employed as the working electrode of H2O2 biosensor. Single-crystalline SnO2 nanorods provide not only low isoelectric point and enough void spaces for facile horseradish peroxidase (HRP immobilization but also numerous conductive channels for electron transport to and from current collector; thus, leading to direct electrochemistry of HRP. The nanorod array-based biosensor demonstrates high H2O2 sensing performance in terms of excellent sensitivity (379 μA mM−1 cm−2, low detection limit (0.2 μM and high selectivity with the apparent Michaelis–Menten constant estimated to be as small as 33.9 μM. Our work further demonstrates the advantages of ordered array architecture in electrochemical device application and sheds light on the construction of other high-performance enzymatic biosensors.

  11. Lactate Biosensor Based on Cellulose Acetate Membrane Bound Lactate Oxidase

    Directory of Open Access Journals (Sweden)

    Suman

    2007-05-01

    Full Text Available Lactate biosensor was fabricated by immobilizing lactate oxidase in cellulose acetate membrane and by mounting over the sensing part of Pt electrode (working and connected to Ag/AgCl electrode (reference along with auxillary electrode through potentiostat. The enzyme electrode was anodically polarized at +400 mV to generate electrons from H2O2, which was formed from oxidation of serum lactate by immobilized lactate oxidase. The minimum detection limit of the electrode was 0.1mmoles/L and sensitivity of the sensor was 0.008 mA/mM/L lactate. Assay coefficients of variation were < 2% .A good correlation (r=0.99 was found between lactate values obtained by colorimetric method and lactate biosensor. The self-life of the biosensor was 18 days at 4ºC and enzyme electrode can be re-used 150 times without any significant loss in enzyme activity.

  12. From Millennium ERM to Proquest 360 Resource Manager: Implementing a new Electronic Resources Management System ERMS in an International Graduate Research University in Saudi Arabia

    KAUST Repository

    Ramli, Rindra M.

    2017-05-17

    An overview of the Recommendation Study and the subsequent Implementation of a new Electronic Resources Management system ERMS in an international graduate research university in the Kingdom of Saudi Arabia. It covers the timeline, deliverables and challenges as well as lessons learnt by the Project Team.

  13. Detection Limits for Nanoscale Biosensors

    National Research Council Canada - National Science Library

    Sheehan, Paul E; Whitman, Lloyd J

    2005-01-01

    We examine through analytical calculations and finite element simulations how the detection efficiency of disk and wire-like biosensors in unmixed fluids varies with size from the micrometer to nanometer scales...

  14. Biosensors based on gold nanostructures

    OpenAIRE

    Vidotti,Marcio; Carvalhal,Rafaela F.; Mendes,Renata K.; Ferreira,Danielle C. M.; Kubota,Lauro T.

    2011-01-01

    The present review discusses the latest advances in biosensor technology achieved by the assembly of biomolecules associated with gold nanoparticles in analytical devices. This review is divided in sections according to the biomolecule employed in the biosensor development: (i) immunocompounds; (ii) DNA/RNA and functional DNA/RNA; and (iii) enzymes and Heme proteins. In order to facilitate the comprehension each section was subdivided according to the transduction mode. Gold nanoparticles bas...

  15. Micro- and nanogap based biosensors

    OpenAIRE

    Hammond, Jules L.

    2017-01-01

    Biosensors are used for the detection of a range of analytes for applications in healthcare, food production, environmental monitoring and biodefence. However, many biosensing platforms are large, expensive, require skilled operators or necessitate the analyte to be labelled. Direct electrochemical detection methods present a particularly attractive platform due to the simplified instrumentation when compared to other techniques such as fluorescence-based biosensors. With modern integrated ci...

  16. Recycling microcavity optical biosensors.

    Science.gov (United States)

    Hunt, Heather K; Armani, Andrea M

    2011-04-01

    Optical biosensors have tremendous potential for commercial applications in medical diagnostics, environmental monitoring, and food safety evaluation. In these applications, sensor reuse is desirable to reduce costs. To achieve this, harsh, wet chemistry treatments are required to remove surface chemistry from the sensor, typically resulting in reduced sensor performance and increased noise due to recognition moiety and optical transducer degradation. In the present work, we suggest an alternative, dry-chemistry method, based on O2 plasma treatment. This approach is compatible with typical fabrication of substrate-based optical transducers. This treatment completely removes the recognition moiety, allowing the transducer surface to be refreshed with new recognition elements and thus enabling the sensor to be recycled.

  17. Electronic tracking of human resource skills and knowledge, just in time training, manageable due diligence

    Energy Technology Data Exchange (ETDEWEB)

    Kolodziej, M.A. [Quick Test International Inc., (Canada). Canadian Technology Human Resource Board; Baker, O. [KeySpan Energy Canada, Calgary, AB (Canada)

    2001-06-01

    KeySpan Energy Canada is in the process of obtaining recognition of various occupational profiles including pipeline operators, inspectors, and field and plant operators from various certifying organizations. The process of allowing individuals to obtain certification is recognized by Canadian Technology Human Resources Board as a step towards national standards for technologists and technicians. Proven competency is a must for workers in todays oil industry in response to increasingly stringent government safety regulations, environmental concerns and high public scrutiny. Quick Test international Inc. has developed a management tool in collaboration with end users at KeySpan Energy Canada. It is an electronic, Internet based competency tool for tracking personal competencies and maintaining continued competency. Response to the tool has been favourable. 2 refs., 4 figs.

  18. DNA nanotechnology-enabled biosensors.

    Science.gov (United States)

    Chao, Jie; Zhu, Dan; Zhang, Yinan; Wang, Lianhui; Fan, Chunhai

    2016-02-15

    Biosensors employ biological molecules to recognize the target and utilize output elements which can translate the biorecognition event into electrical, optical or mass-sensitive signals to determine the quantities of the target. DNA-based biosensors, as a sub-field to biosensor, utilize DNA strands with short oligonucleotides as probes for target recognition. Although DNA-based biosensors have offered a promising alternative for fast, simple and cheap detection of target molecules, there still exist key challenges including poor stability and reproducibility that hinder their competition with the current gold standard for DNA assays. By exploiting the self-recognition properties of DNA molecules, researchers have dedicated to make versatile DNA nanostructures in a highly rigid, controllable and functionalized manner, which offers unprecedented opportunities for developing DNA-based biosensors. In this review, we will briefly introduce the recent advances on design and fabrication of static and dynamic DNA nanostructures, and summarize their applications for fabrication and functionalization of DNA-based biosensors. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Availability, Use and Constraints to Use of Electronic Information Resources by Postgraduates Students at the University of Ibadan

    Directory of Open Access Journals (Sweden)

    Dare Samuel Adeleke

    2017-12-01

    Full Text Available Availability, awareness and use of electronic resources provide access to authoritative, reliable, accurate and timely access to information. The use of electronic information resources (EIRs can enable innovation in teaching and increase timeliness in research of postgraduate students which will eventual result into encouragement of the expected research-led enquiry in this digital age. The study adopted a descriptive survey design. Samples of 300 of postgraduate students within seven out 13 Faculties were randomly selected. Data were collected using questionnaire designed to elicit response from respondents and data were analyzed using descriptive statistics methods percentages, mean, and standard deviation. Results indicated that internet was ranked most available and used in the university. Low level of usage of electronic resources, in particular, full texts data bases is linked to a number of constraints: Interrupted power supply was ranked highest among other factors as speed and capacity of computers, retrieval of records with high recall and low precision, retrieving records relevant to information need, lack of knowledge of search techniques to retrieve information effectively, non possession of requisite IT skills and problems accessing the internet. The study recommended that usage of electronic resources be made compulsory, intensifying awareness campaigns concerning the availability, training on use of electronic resources and the problem of power outage be addressed.

  20. Using mobile electronic devices to deliver educational resources in developing countries.

    Science.gov (United States)

    Mazal, Jonathan Robert; Ludwig, Rebecca

    2015-01-01

    Developing countries have far fewer trained radiography professionals than developed countries, which exacerbates the limited access to imaging services. The lack of trained radiographers reflects, in part, limited availability of radiographer-specific educational resources. Historically, organizations that provided such resources in the developing world faced challenges related to the limited stock of current materials as well as expenses associated with shipping and delivery. Four mobile electronic devices (MEDs) were loaded with educational content (e-books, PDFs, and digital applications) spanning major radiography topics. The MEDs were distributed to 4 imaging departments in Ghana, India, Nepal, and Nigeria based on evidence of need for radiography-specific resources, as revealed by survey responses. A cost comparison of postal delivery vs digital delivery of educational content was performed. The effectiveness of delivering additional content via Wi-Fi transmission also was evaluated. Feedback was solicited on users' experience with the MEDs as a delivery tool for educational content. An initial average per e-book expense of $30.05, which included the cost of the device, was calculated for the MED delivery method compared with $15.56 for postal delivery of printed materials. The cost of the MED delivery method was reduced to an average of $10.05 for subsequent e-book deliveries. Additional content was successfully delivered via Wi-Fi transmission to all recipients during the 3-month follow-up period. Overall user feedback on the experience was positive, and ideas for enhancing the MED-based method were identified. Using MEDs to deliver radiography-specific educational content appears to be more cost effective than postal delivery of printed materials on a long-term basis. MEDs are more efficient for providing updates to educational materials. Customization of content to department needs, and using projector devices could enhance the usefulness of MEDs for

  1. The electronic encapsulation of knowledge in hydraulics, hydrology and water resources

    Science.gov (United States)

    Abbott, Michael B.

    The rapidly developing practice of encapsulating knowledge in electronic media is shown to lead necessarily to the restructuring of the knowledge itself. The consequences of this for hydraulics, hydrology and more general water-resources management are investigated in particular relation to current process-simulation, real-time control and advice-serving systems. The generic properties of the electronic knowledge encapsulator are described, and attention is drawn to the manner in which knowledge 'goes into hiding' through encapsulation. This property is traced in the simple situations of pure mathesis and in the more complex situations of taxinomia using one example each from hydraulics and hydrology. The consequences for systems architectures are explained, pointing to the need for multi-agent architectures for ecological modelling and for more general hydroinformatics systems also. The relevance of these developments is indicated by reference to ongoing projects in which they are currently being realised. In conclusion, some more general epistemological aspects are considered within the same context. As this contribution is so much concerned with the processes of signification and communication, it has been partly shaped by the theory of semiotics, as popularised by Eco ( A Theory of Semiotics, Indiana University, Bloomington, 1977).

  2. Plastics disassembly versus bulk recycling: engineering design for end-of-life electronics resource recovery.

    Science.gov (United States)

    Rios, Pedro; Stuart, Julie Ann; Grant, Ed

    2003-12-01

    Annual plastic flows through the business and consumer electronics manufacturing supply chain include nearly 3 billion lb of high-value engineering plastics derived from petroleum. The recovery of resource value from this stream presents critical challenges in areas of materials identification and recycling process design that demand new green engineering technologies applied together with life cycle assessment and ecological supply chain analysis to create viable plastics-to-plastics supply cycles. The sustainable recovery of potentially high-value engineering plastics streams requires that recyclers either avoid mixing plastic parts or purify later by separating smaller plastic pieces created in volume reduction (shredding) steps. Identification and separation constitute significant barriers in the plastics-to-plastics recycling value proposition. In the present work, we develop a model that accepts randomly arriving electronic products to study scenarios by which a recycler might identify and separate high-value engineering plastics as well as metals. Using discrete eventsimulation,we compare current mixed plastics recovery with spectrochemical plastic resin identification and subsequent sorting. Our results show that limited disassembly with whole-part identification can produce substantial yields in separated streams of recovered engineering thermoplastics. We find that disassembly with identification does not constitute a bottleneck, but rather, with relatively few workers, can be configured to pull the process and thus decrease maximum staging space requirements.

  3. Performance of a Cyanobacteria Whole Cell-Based Fluorescence Biosensor for Heavy Metal and Pesticide Detection

    Directory of Open Access Journals (Sweden)

    Salmijah Surif

    2013-05-01

    Full Text Available Whole cell biosensors always face the challenge of low stability of biological components and short storage life. This paper reports the effects of poly(2-hydroxyethyl methacrylate (pHEMA immobilization on a whole cell fluorescence biosensor for the detection of heavy metals (Cu, Pb, Cd, and pesticides (dichlorophenoxyacetic acid (2,4-D, and chlorpyrifos. The biosensor was produced by entrapping the cyanobacterium Anabaena torulosa on a cellulose membrane, followed by applying a layer of pHEMA, and attaching it to a well. The well was then fixed to an optical probe which was connected to a fluorescence spectrophotometer and an electronic reader. The optimization of the biosensor using several factors such as amount of HEMA and drying temperature were undertaken. The detection limits of biosensor without pHEMA for Cu, Cd, Pb, 2,4-D and chlorpyrifos were 1.195, 0.027, 0.0100, 0.025 and 0.025 µg/L respectively. The presence of pHEMA increased the limits of detection to 1.410, 0.250, 0.500, 0.235 and 0.117 µg/L respectively. pHEMA is known to enhance the reproducibility of the biosensor with average relative standard deviation (RSD of ±1.76% for all the pollutants tested, 48% better than the biosensor without pHEMA (RSD = ±3.73%. In storability test with Cu 5 µg/L, the biosensor with pHEMA performed 11.5% better than the test without pHEMA on day-10 and 5.2% better on day-25. pHEMA is therefore a good candidate to be used in whole cell biosensors as it increases reproducibility and enhances biosensor storability.

  4. Comparative study of thermal stability of magnetostrictive biosensor between two kinds of biorecognition elements

    International Nuclear Information System (INIS)

    Ye, Xue-mei; Guntupalli, R.; Lakshmanan, R.S.; Chin, Bryan A.; Hu, Jing

    2014-01-01

    Magnetostrictive biosensors specific to Salmonella typhimurium were prepared by immobilizing antibody or phage as biorecognition elements onto the magnetostrictive sensor platform. The sensors were stored at temperatures of 25 °C (room temperature), 45 °C and 65 °C, respectively, and the ability to bind S. typhimurium was detected by testing the resonant frequency shift using a HP network analyzer after exposure to 1 mL of 1 × 10 9 cfu/mL of S. typhimurium at a predetermined schedule. The binding of S. typhimurium to biosensors was confirmed by Scanning Electron Microscopy (SEM). The results showed that there existed an initial sudden drop in the average density of S. typhimurium bound to the biosensor surface versus duration at different temperatures for the two kinds of recognition elements, and the binding ability to S. typhimurium of phage-immobilized biosensors was much better than that of antibody-immobilized biosensors, with longevity longer than 30 days at all tested temperatures, though decreasing gradually over the testing period. While the longevity of antibody-immobilized biosensors was only about 30, 8 and 5 days at room temperature (25 °C), 45 °C and 65 °C, respectively. Meanwhile, the activation energy of the two kinds of biosensors was investigated, and it was found that phage immobilized sensors showed much higher activation energy than antibody immobilized sensors, which resulted in less dependency on temperature and thus having much better thermal stability than antibody immobilized sensors. - Highlights: • Phage immobilized biosensors has much better thermal stability. • The longevity of phage immobilized biosensors was longer than 30 days even at 65 °C. • The activation energy of phage immobilized biosensors is much higher

  5. Comparative study of thermal stability of magnetostrictive biosensor between two kinds of biorecognition elements

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Xue-mei [School of Materials Science and Engineering, Changzhou University, Changzhou 213164 (China); Guntupalli, R.; Lakshmanan, R.S.; Chin, Bryan A. [Materials Research and Education Center, Auburn University, AL 36849 (United States); Hu, Jing, E-mail: jinghoo@126.com [School of Materials Science and Engineering, Changzhou University, Changzhou 213164 (China); Materials Research and Education Center, Auburn University, AL 36849 (United States)

    2014-08-01

    Magnetostrictive biosensors specific to Salmonella typhimurium were prepared by immobilizing antibody or phage as biorecognition elements onto the magnetostrictive sensor platform. The sensors were stored at temperatures of 25 °C (room temperature), 45 °C and 65 °C, respectively, and the ability to bind S. typhimurium was detected by testing the resonant frequency shift using a HP network analyzer after exposure to 1 mL of 1 × 10{sup 9} cfu/mL of S. typhimurium at a predetermined schedule. The binding of S. typhimurium to biosensors was confirmed by Scanning Electron Microscopy (SEM). The results showed that there existed an initial sudden drop in the average density of S. typhimurium bound to the biosensor surface versus duration at different temperatures for the two kinds of recognition elements, and the binding ability to S. typhimurium of phage-immobilized biosensors was much better than that of antibody-immobilized biosensors, with longevity longer than 30 days at all tested temperatures, though decreasing gradually over the testing period. While the longevity of antibody-immobilized biosensors was only about 30, 8 and 5 days at room temperature (25 °C), 45 °C and 65 °C, respectively. Meanwhile, the activation energy of the two kinds of biosensors was investigated, and it was found that phage immobilized sensors showed much higher activation energy than antibody immobilized sensors, which resulted in less dependency on temperature and thus having much better thermal stability than antibody immobilized sensors. - Highlights: • Phage immobilized biosensors has much better thermal stability. • The longevity of phage immobilized biosensors was longer than 30 days even at 65 °C. • The activation energy of phage immobilized biosensors is much higher.

  6. NANOSCALE BIOSENSORS IN ECOSYSTEM EXPOSURE RESEARCH

    Science.gov (United States)

    This powerpoint presentation presented information on nanoscale biosensors in ecosystem exposure research. The outline of the presentation is as follows: nanomaterials environmental exposure research; US agencies involved in nanosensor research; nanoscale LEDs in biosensors; nano...

  7. BIOSENSORS FOR ENVIRONMENTAL MONITORING: A REGULATORY PERSPECTIVE

    Science.gov (United States)

    Biosensors show the potential to complement laboratory-based analytical methods for environmental applications. Although biosensors for potential environmental-monitoring applications have been reported for a wide range of environmental pollutants, from a regulatory perspective, ...

  8. SAGES: a suite of freely-available software tools for electronic disease surveillance in resource-limited settings.

    Directory of Open Access Journals (Sweden)

    Sheri L Lewis

    Full Text Available Public health surveillance is undergoing a revolution driven by advances in the field of information technology. Many countries have experienced vast improvements in the collection, ingestion, analysis, visualization, and dissemination of public health data. Resource-limited countries have lagged behind due to challenges in information technology infrastructure, public health resources, and the costs of proprietary software. The Suite for Automated Global Electronic bioSurveillance (SAGES is a collection of modular, flexible, freely-available software tools for electronic disease surveillance in resource-limited settings. One or more SAGES tools may be used in concert with existing surveillance applications or the SAGES tools may be used en masse for an end-to-end biosurveillance capability. This flexibility allows for the development of an inexpensive, customized, and sustainable disease surveillance system. The ability to rapidly assess anomalous disease activity may lead to more efficient use of limited resources and better compliance with World Health Organization International Health Regulations.

  9. Electronic Human Resources Management (e-HRM Adoption Studies: Past and Future Research

    Directory of Open Access Journals (Sweden)

    Winarto Winarto

    2018-05-01

    Full Text Available Electronic human resource management (e-HRM systems become more widely used by profit and non-profit organization. However, the field currently lacks sound theoretical frameworks that can be useful in addressing a key issue concerning the implementation of e-HRM systems, in particular to obtain a better understanding of the factors influencing the adoption of e-HRM systems. The objective of this paper is to provide a foundation towards the development of a theoretical framework for the implementation of e-HRM systems and develop a conceptual model that would reflect the nature of e-HRM systems’ adoption through systematic literature review. Adopting Crossan and Apaydin’s procedure of systematic review, this paper investigated 21 empirical papers of electronics human resources management, then categorized them into 4 characteristics which influence the adoption; System and technology characteristics; Organizational characteristics; User/individual characteristics, and Environmental and contextual characteristics. Finally, the e-HRM adoption research framework is drawn and based on the framework; avenues for future research are discussed.   Bahasa Indonesia Abstrak: Manajemen sumber daya manusia elektronik (selanjutnya disebut dengan e-HRM semakin banyak digunakan oleh organisasi profit dan nonprofit. Namun, bidang dan topik ini belum memiliki kerangka teori yang mapan, yang dapat digunakan untuk menganalisis isu-isu terkait penerapan e-HRM, terutama mengenai faktor-faktor yang mempengaruhi adopsi sistem e-HRM. Tujuan penelitian ini adalah untuk memberikan landasan bagi pengembangan kerangka teoritis untuk implementasi sistem e-HRM dan mengembangkan model konseptual yang akan menggambarkan adopsi sistem e-HRM melalui tinjauan literatur sistematis. Mengadopsi prosedur dan metode Crossan dan Apaydin untuk melakukan telaah literatur secara sistematis, paper ini menyelidiki 21 publikasi empiris manajemen sumber daya manusia elektronik dari 2

  10. Impedimetric biosensors and immunosensors

    International Nuclear Information System (INIS)

    Prodromidis, M.I.

    2007-01-01

    The development of methods targeting the direct monitoring of antibody-antigen interactions is particularly attractive. The design of label-free affinity-based probing concepts is the objective of much current research, at both academic and industrial levels, towards establishing alternative methods to the already existing ELISA-based immunoassays. Among these, Electrochemical Impedance Spectroscopy (EIS) represents one of the most powerful methods, due to the ability of EIS-based sensors to be more easily integrated into multi-array or microprocessor, controlled diagnostic tools. During the last decade, EIS and the concept of biochemical capacitors have been widely used for probing various types of biomolecular interactions (immunosensors, DNA hybridization, protein-protein interactions). So far, impedimetric or capacitive immunosensors have been successfully applied at the academic level. However, no prototypes have been released into the market, since major fundamental issues still exist. Even though this fact has brought the reliability of impedimetric immunosensors into question, features associated with electrochemical approaches, namely the ability to be miniaturized, remote control of implanted sensors, low cost of electrode mass production and cost effective instrumentation (without need of high-energy sources) keep impedimetric sensors particularly attractive as compared to other approaches based on microbalances, surface plasmon resonance or ellipsometry. This lecture outlines the theoretical background of impedimetric immunosensors and presents different types of impedimetric biosensors as well as the instrumental approaches that have been so far proposed in the literature. (author)

  11. An InN/InGaN Quantum Dot Electrochemical Biosensor for Clinical Diagnosis

    Directory of Open Access Journals (Sweden)

    Saima Zaman

    2013-10-01

    Full Text Available Low-dimensional InN/InGaN quantum dots (QDs are demonstrated for realizing highly sensitive and efficient potentiometric biosensors owing to their unique electronic properties. The InN QDs are biochemically functionalized. The fabricated biosensor exhibits high sensitivity of 97 mV/decade with fast output response within two seconds for the detection of cholesterol in the logarithmic concentration range of 1 × 10−6 M to 1 × 10−3 M. The selectivity and reusability of the biosensor are excellent and it shows negligible response to common interferents such as uric acid and ascorbic acid. We also compare the biosensing properties of the InN QDs with those of an InN thin film having the same surface properties, i.e., high density of surface donor states, but different morphology and electronic properties. The sensitivity of the InN QDs-based biosensor is twice that of the InN thin film-based biosensor, the EMF is three times larger, and the response time is five times shorter. A bare InGaN layer does not produce a stable response. Hence, the superior biosensing properties of the InN QDs are governed by their unique surface properties together with the zero-dimensional electronic properties. Altogether, the InN QDs-based biosensor reveals great potential for clinical diagnosis applications.

  12. An InN/InGaN Quantum Dot Electrochemical Biosensor for Clinical Diagnosis

    Science.gov (United States)

    Alvi, Naveed ul Hassan; Gómez, Victor J.; Rodriguez, Paul E.D. Soto; Kumar, Praveen; Zaman, Saima; Willander, Magnus; Nötzel, Richard

    2013-01-01

    Low-dimensional InN/InGaN quantum dots (QDs) are demonstrated for realizing highly sensitive and efficient potentiometric biosensors owing to their unique electronic properties. The InN QDs are biochemically functionalized. The fabricated biosensor exhibits high sensitivity of 97 mV/decade with fast output response within two seconds for the detection of cholesterol in the logarithmic concentration range of 1 × 10−6 M to 1 × 10−3 M. The selectivity and reusability of the biosensor are excellent and it shows negligible response to common interferents such as uric acid and ascorbic acid. We also compare the biosensing properties of the InN QDs with those of an InN thin film having the same surface properties, i.e., high density of surface donor states, but different morphology and electronic properties. The sensitivity of the InN QDs-based biosensor is twice that of the InN thin film-based biosensor, the EMF is three times larger, and the response time is five times shorter. A bare InGaN layer does not produce a stable response. Hence, the superior biosensing properties of the InN QDs are governed by their unique surface properties together with the zero-dimensional electronic properties. Altogether, the InN QDs-based biosensor reveals great potential for clinical diagnosis applications. PMID:24132228

  13. A Study of Wearable Bio-Sensor Technologies and Applications in Healthcare

    Directory of Open Access Journals (Sweden)

    Amir Mehmood

    2017-06-01

    Full Text Available In today’s world the rapid advancements in Micro-Electromechanical Systems (MEMS and Nano technology have improved almost all the aspects of daily life routine with the help of different smart devices such as smart phones, compact electronic devices etc. The prime example of these emerging developments is the development of wireless sensors for healthcare procedures. One kind of these sensors is wearable bio-sensors. In this paper, the technologies of two types of bio-sensors (ECG, EMG are investigated and also compared with traditional ECG, EMG equipment. We have taken SHIMMERTM wireless sensor platform as an example of wearable biosensors technology. We have investigated the systems developed for analysis techniques with SHIMMERTM ECG and EMG wearable bio-sensors and these biosensors are used in continuous remote monitoring. For example, applications in continuous health monitoring of elderly people, critical chronic patients and Fitness & Fatigue observations. Nevertheless, early fall detection in older adults and weak patients, treatment efficacy assessment. This study not only provides the basic concepts of wearable wireless bio-sensors networks (WBSN, but also provides basic knowledge of different sensor platforms available for patient’s remote monitoring. Also various healthcare applications by using bio-sensors are discussed and in last comparison with traditional ECG and EMG is presented.

  14. Nanomolar detection of methylparaben by a cost-effective hemoglobin-based biosensor

    Energy Technology Data Exchange (ETDEWEB)

    Hajian, A., E-mail: ali.hajian@fmf.uni-freiburg.de [Freiburg Materials Research Center, FMF, University of Freiburg, Stefan-Meier-Str.21, 79104 Freiburg (Germany); Laboratory for Sensors, Department of Microsystems Engineering, IMTEK, University of Freiburg, 79110 Freiburg (Germany); Ghodsi, J.; Afraz, A. [Department of Physical Chemistry, Faculty of Chemistry, Bu-Ali Sina University, 65174, Hamedan (Iran, Islamic Republic of); Yurchenko, O. [Freiburg Materials Research Center, FMF, University of Freiburg, Stefan-Meier-Str.21, 79104 Freiburg (Germany); Urban, G. [Freiburg Materials Research Center, FMF, University of Freiburg, Stefan-Meier-Str.21, 79104 Freiburg (Germany); Laboratory for Sensors, Department of Microsystems Engineering, IMTEK, University of Freiburg, 79110 Freiburg (Germany)

    2016-12-01

    This work describes the development of a new biosensor for methylparaben determination using electrocatalytic properties of hemoglobin in the presence of hydrogen peroxide. The voltammetric oxidation of methylparaben by the proposed biosensor in phosphate buffer (pH = 7.0), a physiological pH, was studied and it was confirmed that methylparaben undergoes a one electron-one proton reaction in a diffusion-controlled process. The biosensor was fabricated by carbon paste electrode modified with hemoglobin and multiwalled carbon nanotube. Based on the excellent electrochemical properties of the modified electrode, a sensitive voltammetric method was used for determination of methylparaben within a linear range from 0.1 to 13 μmol L{sup −1} and detection limit of 25 nmol L{sup −1}. The developed biosensor possessed accurate and rapid response to methylparaben and showed good sensitivity, stability, and repeatability. Finally, the applicability of the proposed biosensor was verified by methylparaben evaluation in various real samples. - Highlights: • A new methylparaben biosensor was constructed by modification of carbon paste electrode with hemoglobin and MWCNTs. • The electrochemical properties of the modified electrode and electrochemical behavior of the methylparaben on the electrode surface were studied. • The response of modified GCE was analyzed by voltammetry technique (CV and DPV). • The electrode was used to the determination of methylparaben in real samples • The performance of the fabricated biosensor was satisfactorily compared to the previously reported electrochemical sensors for methylparaben determination.

  15. Gold nanostar-enhanced surface plasmon resonance biosensor based on carboxyl-functionalized graphene oxide

    International Nuclear Information System (INIS)

    Wu, Qiong; Sun, Ying; Ma, Pinyi; Zhang, Di; Li, Shuo; Wang, Xinghua; Song, Daqian

    2016-01-01

    A new high-sensitivity surface plasmon resonance (SPR) biosensor based on biofunctional gold nanostars (AuNSs) and carboxyl-functionalized graphene oxide (cGO) sheets was described. Compared with spherical gold nanoparticles (AuNPs), the anisotropic structure of AuNSs, which concentrates the electric charge density on its sharp tips, could enhance the local electromagnetic field and the electronic coupling effect significantly. cGO was obtained by a diazonium reaction of graphene oxide (GO) with 4-aminobenzoic acid. Compared with GO, cGO could immobilize more antibodies due to the abundant carboxylic groups on its surface. Testing results show that there are fairly large improvements in the analytical performance of the SPR biosensor using cGO/AuNSs-antigen conjugate, and the detection limit of the proposed biosensor is 0.0375 μg mL"−"1, which is 32 times lower than that of graphene oxide-based biosensor. - Highlights: • A sensitive and versatile SPR biosensor was constructed for detection of pig IgG. • Biofunctional gold nanostars were used to amplify the response signals. • The strategy employed carboxyl-functionalized graphene oxide as biosensing substrate. • The detection limit of the proposed biosensor is 32 times lower than that of graphene oxide-based biosensor.

  16. An acetylcholinesterase biosensor based on graphene-gold nanocomposite and calcined layered double hydroxide.

    Science.gov (United States)

    Zhai, Chen; Guo, Yemin; Sun, Xia; Zheng, Yuhe; Wang, Xiangyou

    2014-05-10

    In this study, a novel acetylcholinesterase-based biosensor was fabricated. Acetylcholinesterase (AChE) was immobilized onto a glassy carbon electrode (GCE) with the aid of Cu-Mg-Al calcined layered double hydroxide (CLDH). CLDH can provide a bigger effective surface area for AChE loading, which could improve the precision and stability of AChE biosensor. However, the poor electroconductibility of CLDHs could lead to the low sensitivity of AChE biosensor. In order to effectively compensate the disadvantages of CLDHs, graphene-gold nanocomposites were used for improving the electron transfer rate. Thus, the graphene-gold nanocomposite (GN-AuNPs) was firstly modified onto the GCE, and then the prepared CLDH-AChE composite was immobilized onto the modified GCE to construct a sensitive AChE biosensor for pesticides detection. Relevant parameters were studied in detail and optimized, including the pH of the acetylthiocholine chloride (ATCl) solution, the amount of AChE immobilized on the biosensor and the inhibition time governing the analytical performance of the biosensor. The biosensor detected chlorpyrifos at concentrations ranging from 0.05 to 150μg/L. The detection limit for chlorpyrifos was 0.05μg/L. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Gold nanostar-enhanced surface plasmon resonance biosensor based on carboxyl-functionalized graphene oxide

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Qiong; Sun, Ying; Ma, Pinyi; Zhang, Di; Li, Shuo; Wang, Xinghua; Song, Daqian, E-mail: songdq@jlu.edu.cn

    2016-03-24

    A new high-sensitivity surface plasmon resonance (SPR) biosensor based on biofunctional gold nanostars (AuNSs) and carboxyl-functionalized graphene oxide (cGO) sheets was described. Compared with spherical gold nanoparticles (AuNPs), the anisotropic structure of AuNSs, which concentrates the electric charge density on its sharp tips, could enhance the local electromagnetic field and the electronic coupling effect significantly. cGO was obtained by a diazonium reaction of graphene oxide (GO) with 4-aminobenzoic acid. Compared with GO, cGO could immobilize more antibodies due to the abundant carboxylic groups on its surface. Testing results show that there are fairly large improvements in the analytical performance of the SPR biosensor using cGO/AuNSs-antigen conjugate, and the detection limit of the proposed biosensor is 0.0375 μg mL{sup −1}, which is 32 times lower than that of graphene oxide-based biosensor. - Highlights: • A sensitive and versatile SPR biosensor was constructed for detection of pig IgG. • Biofunctional gold nanostars were used to amplify the response signals. • The strategy employed carboxyl-functionalized graphene oxide as biosensing substrate. • The detection limit of the proposed biosensor is 32 times lower than that of graphene oxide-based biosensor.

  18. Nanomolar detection of methylparaben by a cost-effective hemoglobin-based biosensor

    International Nuclear Information System (INIS)

    Hajian, A.; Ghodsi, J.; Afraz, A.; Yurchenko, O.; Urban, G.

    2016-01-01

    This work describes the development of a new biosensor for methylparaben determination using electrocatalytic properties of hemoglobin in the presence of hydrogen peroxide. The voltammetric oxidation of methylparaben by the proposed biosensor in phosphate buffer (pH = 7.0), a physiological pH, was studied and it was confirmed that methylparaben undergoes a one electron-one proton reaction in a diffusion-controlled process. The biosensor was fabricated by carbon paste electrode modified with hemoglobin and multiwalled carbon nanotube. Based on the excellent electrochemical properties of the modified electrode, a sensitive voltammetric method was used for determination of methylparaben within a linear range from 0.1 to 13 μmol L −1 and detection limit of 25 nmol L −1 . The developed biosensor possessed accurate and rapid response to methylparaben and showed good sensitivity, stability, and repeatability. Finally, the applicability of the proposed biosensor was verified by methylparaben evaluation in various real samples. - Highlights: • A new methylparaben biosensor was constructed by modification of carbon paste electrode with hemoglobin and MWCNTs. • The electrochemical properties of the modified electrode and electrochemical behavior of the methylparaben on the electrode surface were studied. • The response of modified GCE was analyzed by voltammetry technique (CV and DPV). • The electrode was used to the determination of methylparaben in real samples • The performance of the fabricated biosensor was satisfactorily compared to the previously reported electrochemical sensors for methylparaben determination.

  19. Diabetes mellitus: biosensors for research and management.

    Science.gov (United States)

    Turner, A P; Pickup, J C

    1985-01-01

    The condition of diabetes mellitus is described with particular reference to the parameters that it would be desirable to monitor in order to improve management and understanding of the disease. Previous attention has largely focused on analysis of glucose, but many other intermediates of carbohydrate, fat and protein metabolism are deranged in diabetes and may be alternative measures of control. The need for laboratory analysers, self-monitoring, closed-loop devices and alarms are detailed and the problems associated with implantable sensors discussed. Progress in the development of biosensors is reviewed using glucose sensors as the main example. Electrochemical, optoelectronic and calorimetric approaches to sensing are considered and it is concluded that configurations based either on hydrogen peroxide detection or on mediated electron transfer are most likely to provide a raid route to in vivo monitoring. The extension of biosensor technology to tackle other important substrates is discussed, the principal hurdle to success being seen as the lack of long-term stability of the biological component.

  20. Recent Advances in Magnetic Microfluidic Biosensors

    Directory of Open Access Journals (Sweden)

    Ioanna Giouroudi

    2017-07-01

    Full Text Available The development of portable biosening devices for the detection of biological entities such as biomolecules, pathogens, and cells has become extremely significant over the past years. Scientific research, driven by the promise for miniaturization and integration of complex laboratory equipment on inexpensive, reliable, and accurate devices, has successfully shifted several analytical and diagnostic methods to the submillimeter scale. The miniaturization process was made possible with the birth of microfluidics, a technology that could confine, manipulate, and mix very small volumes of liquids on devices integrated on standard silicon technology chips. Such devices are then directly translating the presence of these entities into an electronic signal that can be read out with a portable instrumentation. For the aforementioned tasks, the use of magnetic markers (magnetic particles—MPs—functionalized with ligands in combination with the application of magnetic fields is being strongly investigated by research groups worldwide. The greatest merits of using magnetic fields are that they can be applied either externally or from integrated microconductors and they can be well-tuned by adjusting the applied current on the microconductors. Moreover, the magnetic markers can be manipulated inside microfluidic channels by high gradient magnetic fields that can in turn be detected by magnetic sensors. All the above make this technology an ideal candidate for the development of such microfluidic biosensors. In this review, focus is given only to very recent advances in biosensors that use microfluidics in combination with magnetic sensors and magnetic markers/nanoparticles.

  1. Facile fabrication of gold nanoparticle on zein ultrafine fibers and their application for catechol biosensor

    International Nuclear Information System (INIS)

    Chen, Xiaodong; Li, Dawei; Li, Guohui; Luo, Lei; Ullah, Naseeb; Wei, Qufu; Huang, Fenglin

    2015-01-01

    Graphical abstract: (A) Formation mechanism of A-CZNF and (B) reaction principle and formation mechanism of A-CZUF biosensor. - Highlights: • We utilized the hydrophobic protein nanofibers to fabricate a laccase-based biosensor for the first time. • The composite containing gold nanoparticles was prepared by combining electrospinning and one-step reduction method, which is a novel nanomaterial. • It is noticeable that the laccase biosensor showed a high electrochemical response and electrochemical activity toward catechol. • The novel biosensor will offer a simple, convenient and high efficient method for detecting polyphenolic compounds in environment. - Abstract: A novel laccase biosensor based on a new composite of laccase–gold nanoparticles (Au NPs)-crosslinked zein ultrafine fibers (CZUF) has been fabricated for catechol determination in real solution samples. Firstly, crosslinked zein ultrafine fibers containing gold nanoparticles (A-CZUF) were prepared by combining electrospinning and one-step reduction method using poly(ethyleneimine) (PEI) as reducing and crosslinking agent. A smooth morphology and relative average distribution of A-CZUF were depicted by scanning electron microscope (SEM) and transmission electron microscopy (TEM). The Fourier transform infrared spectroscopy (FT-IR) analysis indicated that PEI molecules attached to the surface of the zein ultrafine fibers via the reaction of functional groups between PEI and glyoxal. The results obtained from ultraviolet visible spectroscopy (UV–vis spectroscopy), X-ray diffraction (XRD) and thermal gravimetric analysis (TGA) for A-CZUF confirmed the existence of Au NPS coated on the surface of CZUF. Square wave voltammetry (SWV) and cyclic voltammetry (CV) were used to detect the electrochemical performance of the proposed biosensor. The results demonstrated that this biosensor possessed a high sensitive detection to catechol, which was attributed to the direct electron transfer (DET

  2. Impact of Electronic Resources and Usage in Academic Libraries in Ghana: Evidence from Koforidua Polytechnic & All Nations University College, Ghana

    Science.gov (United States)

    Akussah, Maxwell; Asante, Edward; Adu-Sarkodee, Rosemary

    2015-01-01

    The study investigates the relationship between impact of electronic resources and its usage in academic libraries in Ghana: evidence from Koforidua Polytechnic & All Nations University College, Ghana. The study was a quantitative approach using questionnaire to gather data and information. A valid response rate of 58.5% was assumed. SPSS…

  3. Utilization of Electronic Information Resources by Undergraduate Students of University of Ibadan: A Case Study of Social Sciences and Education

    Science.gov (United States)

    Owolabi, Sola; Idowu, Oluwafemi A.; Okocha, Foluke; Ogundare, Atinuke Omotayo

    2016-01-01

    The study evaluated utilization of electronic information resources by undergraduates in the Faculties of Education and the Social Sciences in University of Ibadan. The study adopted a descriptive survey design with a study population of 1872 undergraduates in the Faculties of Education and the Social Sciences in University of Ibadan, from which a…

  4. Analytical modeling of glucose biosensors based on carbon nanotubes.

    Science.gov (United States)

    Pourasl, Ali H; Ahmadi, Mohammad Taghi; Rahmani, Meisam; Chin, Huei Chaeng; Lim, Cheng Siong; Ismail, Razali; Tan, Michael Loong Peng

    2014-01-15

    In recent years, carbon nanotubes have received widespread attention as promising carbon-based nanoelectronic devices. Due to their exceptional physical, chemical, and electrical properties, namely a high surface-to-volume ratio, their enhanced electron transfer properties, and their high thermal conductivity, carbon nanotubes can be used effectively as electrochemical sensors. The integration of carbon nanotubes with a functional group provides a good and solid support for the immobilization of enzymes. The determination of glucose levels using biosensors, particularly in the medical diagnostics and food industries, is gaining mass appeal. Glucose biosensors detect the glucose molecule by catalyzing glucose to gluconic acid and hydrogen peroxide in the presence of oxygen. This action provides high accuracy and a quick detection rate. In this paper, a single-wall carbon nanotube field-effect transistor biosensor for glucose detection is analytically modeled. In the proposed model, the glucose concentration is presented as a function of gate voltage. Subsequently, the proposed model is compared with existing experimental data. A good consensus between the model and the experimental data is reported. The simulated data demonstrate that the analytical model can be employed with an electrochemical glucose sensor to predict the behavior of the sensing mechanism in biosensors.

  5. Amperometric urea biosensors based on sulfonated graphene/polyaniline nanocomposite

    Directory of Open Access Journals (Sweden)

    Das G

    2015-08-01

    Full Text Available Gautam Das, Hyon Hee Yoon Department of Chemical and Biological Engineering, Gachon University, Seongnam, Gyeonggi-do, South Korea Abstract: An electrochemical biosensor based on sulfonated graphene/polyaniline nanocomposite was developed for urea analysis. Oxidative polymerization of aniline in the presence of sulfonated graphene oxide was carried out by electrochemical methods in an aqueous environment. The structural properties of the nanocomposite were characterized by Fourier-transform infrared, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy techniques. The urease enzyme-immobilized sulfonated graphene/polyaniline nanocomposite film showed impressive performance in the electroanalytical detection of urea with a detection limit of 0.050 mM and a sensitivity of 0.85 µA·cm-2·mM-1. The biosensor achieved a broad linear range of detection (0.12–12.3 mM with a notable response time of approximately 5 seconds. Moreover, the fabricated biosensor retained 81% of its initial activity (based on sensitivity after 15 days of storage at 4°C. The ease of fabrication coupled with the low cost and good electrochemical performance of this system holds potential for the development of solid-state biosensors for urea detection. Keywords: electrochemical deposition, sulfonated graphene oxide, urease

  6. Scattering-Type Surface-Plasmon-Resonance Biosensors

    Science.gov (United States)

    Wang, Yu; Pain, Bedabrata; Cunningham, Thomas; Seshadri, Suresh

    2005-01-01

    Biosensors of a proposed type would exploit scattering of light by surface plasmon resonance (SPR). Related prior biosensors exploit absorption of light by SPR. Relative to the prior SPR biosensors, the proposed SPR biosensors would offer greater sensitivity in some cases, enough sensitivity to detect bioparticles having dimensions as small as nanometers. A surface plasmon wave can be described as a light-induced collective oscillation in electron density at the interface between a metal and a dielectric. At SPR, most incident photons are either absorbed or scattered at the metal/dielectric interface and, consequently, reflected light is greatly attenuated. The resonance wavelength and angle of incidence depend upon the permittivities of the metal and dielectric. An SPR sensor of the type most widely used heretofore includes a gold film coated with a ligand a substance that binds analyte molecules. The gold film is thin enough to support evanescent-wave coupling through its thickness. The change in the effective index of refraction at the surface, and thus the change in the SPR response, increases with the number of bound analyte molecules. The device is illuminated at a fixed wavelength, and the intensity of light reflected from the gold surface opposite the ligand-coated surface is measured as a function of the angle of incidence. From these measurements, the angle of minimum reflection intensity is determined

  7. Micro-and nanoelectromechanical biosensors

    CERN Document Server

    Nicu, Liviu

    2014-01-01

    Most books dedicated to the issues of bio-sensing are organized by the well-known scheme of a biosensor. In this book, the authors have deliberately decided to break away from the conventional way of treating biosensing research by uniquely addressing biomolecule immobilization methods on a solid surface, fluidics issues and biosensing-related transduction techniques, rather than focusing simply on the biosensor. The aim is to provide a contemporary snapshot of the biosensing landscape without neglecting the seminal references or products where needed, following the downscaling (from the micr

  8. Systematic review of electronic surveillance of infectious diseases with emphasis on antimicrobial resistance surveillance in resource-limited settings.

    Science.gov (United States)

    Rattanaumpawan, Pinyo; Boonyasiri, Adhiratha; Vong, Sirenda; Thamlikitkul, Visanu

    2018-02-01

    Electronic surveillance of infectious diseases involves rapidly collecting, collating, and analyzing vast amounts of data from interrelated multiple databases. Although many developed countries have invested in electronic surveillance for infectious diseases, the system still presents a challenge for resource-limited health care settings. We conducted a systematic review by performing a comprehensive literature search on MEDLINE (January 2000-December 2015) to identify studies relevant to electronic surveillance of infectious diseases. Study characteristics and results were extracted and systematically reviewed by 3 infectious disease physicians. A total of 110 studies were included. Most surveillance systems were developed and implemented in high-income countries; less than one-quarter were conducted in low-or middle-income countries. Information technologies can be used to facilitate the process of obtaining laboratory, clinical, and pharmacologic data for the surveillance of infectious diseases, including antimicrobial resistance (AMR) infections. These novel systems require greater resources; however, we found that using electronic surveillance systems could result in shorter times to detect targeted infectious diseases and improvement of data collection. This study highlights a lack of resources in areas where an effective, rapid surveillance system is most needed. The availability of information technology for the electronic surveillance of infectious diseases, including AMR infections, will facilitate the prevention and containment of such emerging infectious diseases. Copyright © 2018 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  9. Biosensors in Clinical Practice: Focus on Oncohematology

    Directory of Open Access Journals (Sweden)

    Agostino Cortelezzi

    2013-05-01

    Full Text Available Biosensors are devices that are capable of detecting specific biological analytes and converting their presence or concentration into some electrical, thermal, optical or other signal that can be easily analysed. The first biosensor was designed by Clark and Lyons in 1962 as a means of measuring glucose. Since then, much progress has been made and the applications of biosensors are today potentially boundless. This review is limited to their clinical applications, particularly in the field of oncohematology. Biosensors have recently been developed in order to improve the diagnosis and treatment of patients affected by hematological malignancies, such as the biosensor for assessing the in vitro pre-treatment efficacy of cytarabine in acute myeloid leukemia, and the fluorescence resonance energy transfer-based biosensor for assessing the efficacy of imatinib in chronic myeloid leukemia. The review also considers the challenges and future perspectives of biosensors in clinical practice.

  10. Nanomaterials-based enzyme electrochemical biosensors operating through inhibition for biosensing applications.

    Science.gov (United States)

    Kurbanoglu, Sevinc; Ozkan, Sibel A; Merkoçi, Arben

    2017-03-15

    In recent years great progress has been made in applying nanomaterials to design novel biosensors. Use of nanomaterials offers to biosensing platforms exceptional optical, electronic and magnetic properties. Nanomaterials can increase the surface of the transducing area of the sensors that in turn bring an increase in catalytic behaviors. They have large surface-to-volume ratio, controlled morphology and structure that also favor miniaturization, an interesting advantage when the sample volume is a critical issue. Biosensors have great potential for achieving detect-to-protect devices: devices that can be used in detections of pollutants and other treating compounds/analytes (drugs) protecting citizens' life. After a long term focused scientific and financial efforts/supports biosensors are expected now to fulfill their promise such as being able to perform sampling and analysis of complex samples with interest for clinical or environment fields. Among all types of biosensors, enzymatic biosensors, the most explored biosensing devices, have an interesting property, the inherent inhibition phenomena given the enzyme-substrate complex formation. The exploration of such phenomena is making remarkably important their application as research and applied tools in diagnostics. Different inhibition biosensor systems based on nanomaterials modification has been proposed and applied. The role of nanomaterials in inhibition-based biosensors for the analyses of different groups of drugs as well as contaminants such as pesticides, phenolic compounds and others, are discussed in this review. This deep analysis of inhibition-based biosensors that employ nanomaterials will serve researchers as a guideline for further improvements and approaching of these devices to real sample applications so as to reach society needs and such biosensor market demands. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. A luminescent nisin biosensor

    Science.gov (United States)

    Immonen, Nina; Karp, Matti

    2006-02-01

    Nisin is a lantibiotic, an antibacterial peptide produced by certain Lactococcus lactis strains that kills or inhibits the growth of other bacteria. Nisin is widely used as a food preservative, and its long-time use suggests that it can be generally regarded as safe. We have developed a method for determining the amount of nisin in food samples that is based on luminescent biosensor bacteria. Bacterial luciferase operon luxABCDE was inserted into plasmid pNZ8048, and the construct was transformed by electroporation into Lc. lactis strain NZ9800, whose ability to produce nisin has been erased by deletion of the gene nisA. The operon luxABCDE has been modified to be functional in gram-positive bacteria to confer a bioluminescent phenotype without the requirement of adding an exogenous substrate. In the plasmid pNZ8048, the operon was placed under control of the nisin-inducible nisA promoter. The chromosomal nisRK genes of Lc. lactis NZ9800 allow it to sense nisin in the environment and relay this signal via signal transduction proteins NisK and NisR to initiate transcription from nisA promoter. In the case of our sensor bacteria, this leads to production of luciferase and, thus, luminescence that can be directly measured from living bacteria. Luminescence can be detected as early as within minutes of induction. The nisin assay described here provides a detection limit in the sub-picogram level per ml, and a linear area between 1 - 1000 pg/ml. The sensitivity of this assay exceeds the performance of all previously published methods.

  12. The Use of Electronic Resources by Academic Staff at the University of Ilorin, Nigeria

    Science.gov (United States)

    Tella, Adeyinka; Orim, Faith; Ibrahim, Dauda Morenikeji; Memudu, Suleiman Ajala

    2018-01-01

    The use of e-resources is now commonplace among academics in tertiary educational institutions the world over. Many academics including those in the universities are exploring the opportunities of e-resources to facilitate teaching and research. As the use of e-resources is increasing particularly among academics at the University of Ilorin,…

  13. Modeling antecedents of electronic medical record system implementation success in low-resource setting hospitals.

    Science.gov (United States)

    Tilahun, Binyam; Fritz, Fleur

    2015-08-01

    With the increasing implementation of Electronic Medical Record Systems (EMR) in developing countries, there is a growing need to identify antecedents of EMR success to measure and predict the level of adoption before costly implementation. However, less evidence is available about EMR success in the context of low-resource setting implementations. Therefore, this study aims to fill this gap by examining the constructs and relationships of the widely used DeLone and MacLean (D&M) information system success model to determine whether it can be applied to measure EMR success in those settings. A quantitative cross sectional study design using self-administered questionnaires was used to collect data from 384 health professionals working in five governmental hospitals in Ethiopia. The hospitals use a comprehensive EMR system since three years. Descriptive and structural equation modeling methods were applied to describe and validate the extent of relationship of constructs and mediating effects. The findings of the structural equation modeling shows that system quality has significant influence on EMR use (β = 0.32, P quality has significant influence on EMR use (β = 0.44, P service quality has strong significant influence on EMR use (β = 0.36, P effect of EMR use on user satisfaction was not significant. Both EMR use and user satisfaction have significant influence on perceived net-benefit (β = 0.31, P mediating factor in the relationship between service quality and EMR use (P effect on perceived net-benefit of health professionals. EMR implementers and managers in developing countries are in urgent need of implementation models to design proper implementation strategies. In this study, the constructs and relationships depicted in the updated D&M model were found to be applicable to assess the success of EMR in low resource settings. Additionally, computer literacy was found to be a mediating factor in EMR use and user satisfaction of

  14. Monitoring of Glucose in Beer Brewing by a Carbon Nanotubes Based Nylon Nanofibrous Biosensor

    Directory of Open Access Journals (Sweden)

    Marco Mason

    2016-01-01

    Full Text Available This work presents the design, preparation, and characterization of a novel glucose electrochemical biosensor based on the immobilization of glucose oxidase (GOX into a nylon nanofibrous membrane (NFM prepared by electrospinning and functionalized with multiwalled carbon nanotubes (CNT. A disc of such GOX/CNT/NFM membrane (40 μm in thickness was used for coating the surface of a glassy carbon electrode. The resulting biosensor was characterized by cyclic voltammetry and chronoamperometry, with ferrocene methanol as mediator. The binding of GOX around the CNT/NFM greatly enhances the electron transfer, which results in a biosensor with a current five times higher than without CNT. The potential usefulness of the proposed biosensor was demonstrated with the analysis of glucose in commercial beverages and along the monitoring of the brewing process for making beer, from the mashing to the fermentation steps.

  15. A disposable biosensor based on immobilization of laccase with silica spheres on the MWCNTs-doped screen-printed electrode

    Directory of Open Access Journals (Sweden)

    Li Yuanting

    2012-09-01

    Full Text Available Abstract Background Biosensors have attracted increasing attention as reliable analytical instruments in in situ monitoring of public health and environmental pollution. For enzyme-based biosensors, the stabilization of enzymatic activity on the biological recognition element is of great importance. It is generally acknowledged that an effective immobilization technique is a key step to achieve the construction quality of biosensors. Results A novel disposable biosensor was constructed by immobilizing laccase (Lac with silica spheres on the surface of multi-walled carbon nanotubes (MWCNTs-doped screen-printed electrode (SPE. Then, it was characterized in morphology and electrochemical properties by scanning electron microscopy (SEM and cyclic voltammetry (CV. The characterization results indicated that a high loading of Lac and a good electrocatalytic activity could be obtained, attributing to the porous structure, large specific area and good biocompatibility of silica spheres and MWCNTs. Furthermore, the electrochemical sensing properties of the constructed biosensor were investigated by choosing dopamine (DA as the typical model of phenolic compounds. It was shown that the biosensor displays a good linearity in the range from 1.3 to 85.5 μM with a detection limit of 0.42 μM (S/N = 3, and the Michaelis-Menten constant (Kmapp was calculated to be 3.78 μM. Conclusion The immobilization of Lac was successfully achieved with silica spheres to construct a disposable biosensor on the MWCNTs-doped SPE (MWCNTs/SPE. This biosensor could determine DA based on a non-oxidative mechanism in a rapid, selective and sensitive way. Besides, the developed biosensor could retain high enzymatic activity and possess good stability without cross-linking reagents. The proposed immobilization approach and the constructed biosensor offer a great potential for the fabrication of the enzyme-based biosensors and the analysis of phenolic compounds.

  16. Magneto-elastic biosensors: Influence of different thiols on pathogen capture efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Dalla Pozza, Márcia; Possan, André L. [Centro de Ciências Exatas e Tecnologia, Universidade de Caxias do Sul, Caxias do Sul, RS (Brazil); Roesch-Ely, Mariana [Instituto de Biotecnologia, Universidade de Caxias do Sul, Caxias do Sul, RS (Brazil); Missell, Frank P., E-mail: fpmissel@ucs.br [Centro de Ciências Exatas e Tecnologia, Universidade de Caxias do Sul, Caxias do Sul, RS (Brazil)

    2017-06-01

    Magneto-elastic biosensors have mass sensitivity to biological species, offering reliability and reproducibility in the detection of pathogens such as Escherichia coli. In this work, amorphous ribbons of Metglas 2826MB3 were coated with layers of Cr and Au by DC magnetron sputtering and cut to 5 mm × 1 mm. The influence of different thiols on captured pathogens was studied. The compounds cystamine (CYS), cysteamine (CYSTE) and mercaptopropionic acid (MPA) were deposited on Au-covered surfaces, followed by antibodies. The roughness parameters Ra and Rq were determined using atomic force microscopy (AFM) and micrographs from scanning electron microscopy with a field emission gun (FESEM) were also utilized. Biosensors formed with MPA showed an increased efficiency for attracting E. coli compared to biosensors with CYS and CYSTE, but large standard deviations were observed, making reproducibility and reliability difficult for that biosensor. Sensors tested with CYSTE showed greater efficiency and a lower detection limit than sensors with CYS. The results indicated that the size of the carbon chain and the terminal grouping influence the effectiveness of immobilization on magneto-elastic biosensors. - Highlights: • Atomic force microscopy (AFM) and scanning electron microscopy with field emission gun (FESEM) were utilized. • Biosensor with cysteamine (CYSTE) gave lower detection limit for E.coli than mercaptopropionic acid (MPA) or cystamine (CYS)

  17. Potential application of hemoglobin as an alternative to peroxidase in a phenol biosensor

    International Nuclear Information System (INIS)

    Kafi, A.K.M.; Lee, Dong-Yun; Park, Sang-Hyun; Kwon, Young-Soo

    2008-01-01

    This work describes a new amperometric biosensor for detecting phenolic compounds. The sensor was designed by immobilizing Hemoglobin (Hb) in a sol-gel matrix onto a carbon electrode. Using the peroxidase activity of Hb, the phenolic compound can be reduced in the presence of H 2 O 2 . The biosensor's performance in phenolic compound detection was based on mediated electron transfer by Hb. The direct electron transfer of Hb can be avoided by use of the sol-gel matrix. The proposed biosensor presents a very sensitive response for phenolic compounds at an applied potential of 0.0 mV vs. Ag/AgCl. The parameters of the fabrication process for the electrode were optimized. Experimental conditions influencing the biosensor performance, such as pH and potential, were investigated and assessed. Various types of phenolic compounds were detected. Among them, using the optimized conditions, a linearity for the detection of the phenol was observed from 5 μM to 50 μM. Biosensor response levels after 30 days were at more than 80% of their initial response readings level. The response time of the biosensor was about 10 s

  18. Magneto-elastic biosensors: Influence of different thiols on pathogen capture efficiency

    International Nuclear Information System (INIS)

    Dalla Pozza, Márcia; Possan, André L.; Roesch-Ely, Mariana; Missell, Frank P.

    2017-01-01

    Magneto-elastic biosensors have mass sensitivity to biological species, offering reliability and reproducibility in the detection of pathogens such as Escherichia coli. In this work, amorphous ribbons of Metglas 2826MB3 were coated with layers of Cr and Au by DC magnetron sputtering and cut to 5 mm × 1 mm. The influence of different thiols on captured pathogens was studied. The compounds cystamine (CYS), cysteamine (CYSTE) and mercaptopropionic acid (MPA) were deposited on Au-covered surfaces, followed by antibodies. The roughness parameters Ra and Rq were determined using atomic force microscopy (AFM) and micrographs from scanning electron microscopy with a field emission gun (FESEM) were also utilized. Biosensors formed with MPA showed an increased efficiency for attracting E. coli compared to biosensors with CYS and CYSTE, but large standard deviations were observed, making reproducibility and reliability difficult for that biosensor. Sensors tested with CYSTE showed greater efficiency and a lower detection limit than sensors with CYS. The results indicated that the size of the carbon chain and the terminal grouping influence the effectiveness of immobilization on magneto-elastic biosensors. - Highlights: • Atomic force microscopy (AFM) and scanning electron microscopy with field emission gun (FESEM) were utilized. • Biosensor with cysteamine (CYSTE) gave lower detection limit for E.coli than mercaptopropionic acid (MPA) or cystamine (CYS)

  19. Nanomaterials towards fabrication of cholesterol biosensors: Key roles and design approaches.

    Science.gov (United States)

    Saxena, Urmila; Das, Asim Bikas

    2016-01-15

    Importance of cholesterol biosensors is already recognized in the clinical diagnosis of cardiac and brain vascular diseases as discernible from the enormous amount of research in this field. Nevertheless, the practical application of a majority of the fabricated cholesterol biosensors is ordinarily limited by their inadequate performance in terms of one or more analytical parameters including stability, sensitivity and detection limit. Nanoscale materials offer distinctive size tunable electronic, catalytic and optical properties which opened new opportunities for designing highly efficient biosensor devices. Incorporation of nanomaterials in biosensing devices has found to improve the electroactive surface, electronic conductivity and biocompatibility of the electrode surfaces which then improves the analytical performance of the biosensors. Here we have reviewed recent advances in nanomaterial-based cholesterol biosensors. Foremost, the diverse roles of nanomaterials in these sensor systems have been discussed. Later, we have exhaustively explored the strategies used for engineering cholesterol biosensors with nanotubes, nanoparticles and nanocomposites. Finally, this review concludes with future outlook signifying some challenges of these nanoengineered cholesterol sensors. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Monitoring RAYT activity by surface plasmon resonance biosensor

    Czech Academy of Sciences Publication Activity Database

    Bocková, Markéta; Špringer, Tomáš; Nečasová, Iva; Nunvář, Jaroslav; Schneider, Bohdan; Homola, Jiří

    2015-01-01

    Roč. 407, č. 14 (2015), s. 3985-3993 ISSN 1618-2642 R&D Projects: GA ČR GAP305/12/1801 Grant - others:GA MŠk(CZ) CZ.1.05/1.1.00/02.0109 Institutional support: RVO:67985882 ; RVO:86652036 Keywords : Surface plasmon resonance * Biosensor * REP-associated tyrosine transposase Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering; EB - Genetics ; Molecular Biology (BTO-N) Impact factor: 3.125, year: 2015

  1. Nanopatterned Bulk Metallic Glass Biosensors.

    Science.gov (United States)

    Kinser, Emily R; Padmanabhan, Jagannath; Yu, Roy; Corona, Sydney L; Li, Jinyang; Vaddiraju, Sagar; Legassey, Allen; Loye, Ayomiposi; Balestrini, Jenna; Solly, Dawson A; Schroers, Jan; Taylor, André D; Papadimitrakopoulos, Fotios; Herzog, Raimund I; Kyriakides, Themis R

    2017-12-22

    Nanopatterning as a surface area enhancement method has the potential to increase signal and sensitivity of biosensors. Platinum-based bulk metallic glass (Pt-BMG) is a biocompatible material with electrical properties conducive for biosensor electrode applications, which can be processed in air at comparably low temperatures to produce nonrandom topography at the nanoscale. Work presented here employs nanopatterned Pt-BMG electrodes functionalized with glucose oxidase enzyme to explore the impact of nonrandom and highly reproducible nanoscale surface area enhancement on glucose biosensor performance. Electrochemical measurements including cyclic voltammetry (CV) and amperometric voltammetry (AV) were completed to compare the performance of 200 nm Pt-BMG electrodes vs Flat Pt-BMG control electrodes. Glucose dosing response was studied in a range of 2 mM to 10 mM. Effective current density dynamic range for the 200 nm Pt-BMG was 10-12 times greater than that of the Flat BMG control. Nanopatterned electrode sensitivity was measured to be 3.28 μA/cm 2 /mM, which was also an order of magnitude greater than the flat electrode. These results suggest that nonrandom nanotopography is a scalable and customizable engineering tool which can be integrated with Pt-BMGs to produce biocompatible biosensors with enhanced signal and sensitivity.

  2. Improved Ion-Channel Biosensors

    Science.gov (United States)

    Nadeau, Jay; White, Victor; Dougherty, Dennis; Maurer, Joshua

    2004-01-01

    An effort is underway to develop improved biosensors of a type based on ion channels in biomimetic membranes. These sensors are microfabricated from silicon and other materials compatible with silicon. As described, these sensors offer a number of advantages over prior sensors of this type.

  3. An electromagnetic system for biosensors

    NARCIS (Netherlands)

    2008-01-01

    The invention relates to an electromagnetic system for biosensors, in which the system can switch quickly between high magnetic gradients, without the need of movement of mech. elements. This is realized by two independent emu which are sepd. in the region of the pole shoes over a gap, in which a

  4. Development of Biosensors From Graphene

    Institute of Scientific and Technical Information of China (English)

    高瑞红; 孙红; 李霄寒; 于冲

    2017-01-01

    Graphene's success has stimulated great interest and research in the synthesis and characterization of graphene -like 2D materials, single and few -atom -thick layers of van der Waals materials, which show fascinating and technologically useful properties.This review presents an overview of recent electrochemical sensors and biosensors based on graphene and on graphene-like 2D materials.

  5. Fiber optic-based biosensor

    Science.gov (United States)

    Ligler, Frances S.

    1991-01-01

    The NRL fiber optic biosensor is a device which measures the formation of a fluorescent complex at the surface of an optical fiber. Antibodies and DNA binding proteins provide the mechanism for recognizing an analyze and immobilizing a fluorescent complex on the fiber surface. The fiber optic biosensor is fast, sensitive, and permits analysis of hazardous materials remote from the instrumentation. The fiber optic biosensor is described in terms of the device configuration, chemistry for protein immobilization, and assay development. A lab version is being used for assay development and performance characterization while a portable device is under development. Antibodies coated on the fiber are stable for up to two years of storage prior to use. The fiber optic biosensor was used to measure concentration of toxins in the parts per billion (ng/ml) range in under a minute. Immunoassays for small molecules and whole bacteria are under development. Assays using DNA probes as the detection element can also be used with the fiber optic sensor, which is currently being developed to detect biological warfare agents, explosives, pathogens, and toxic materials which pollute the environment.

  6. Biosensors and multiple mycotoxin analysis

    NARCIS (Netherlands)

    Gaag, B. van der; Spath, S.; Dietrich, H.; Stigter, E.; Boonzaaijer, G.; Osenbruggen, T. van; Koopal, K.

    2003-01-01

    An immunochemical biosensor assay for the detection of multiple mycotoxins in a sample is described.The inhibition assay is designed to measure four different mycotoxins in a single measurement, following extraction, sample clean-up and incubation with an appropriate cocktail of anti-mycotoxin

  7. A High-Content Assay for Biosensor Validation and for Examining Stimuli that Affect Biosensor Activity.

    Science.gov (United States)

    Slattery, Scott D; Hahn, Klaus M

    2014-12-01

    Biosensors are valuable tools used to monitor many different protein behaviors in vivo. Demand for new biosensors is high, but their development and characterization can be difficult. During biosensor design, it is necessary to evaluate the effects of different biosensor structures on specificity, brightness, and fluorescence responses. By co-expressing the biosensor with upstream proteins that either stimulate or inhibit the activity reported by the biosensor, one can determine the difference between the biosensor's maximally activated and inactivated state, and examine response to specific proteins. We describe here a method for biosensor validation in a 96-well plate format using an automated microscope. This protocol produces dose-response curves, enables efficient examination of many parameters, and unlike cell suspension assays, allows visual inspection (e.g., for cell health and biosensor or regulator localization). Optimization of single-chain and dual-chain Rho GTPase biosensors is addressed, but the assay is applicable to any biosensor that can be expressed or otherwise loaded in adherent cells. The assay can also be used for purposes other than biosensor validation, using a well-characterized biosensor as a readout for effects of upstream molecules. Copyright © 2014 John Wiley & Sons, Inc.

  8. Use and Cost of Electronic Resources in Central Library of Ferdowsi University Based on E-metrics

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Davarpanah

    2012-07-01

    Full Text Available The purpose of this study was to investigate the usage of electronic journals in Ferdowsi University, Iran based on e-metrics. The paper also aimed to emphasize the analysis of cost-benefit and the correlation between the journal impact factors and the usage data. In this study experiences of Ferdowsi University library on licensing and usage of electronic resources was evaluated by providing a cost-benefit analysis based on the cost and usage statistics of electronic resources. Vendor-provided data were also compared with local usage data. The usage data were collected by tracking web-based access locally, and by collecting vender-provided usage data. The data sources were one-year of vendor-supplied e-resource usage data such as Ebsco, Elsevier, Proquest, Emerald, Oxford and Springer and local usage data collected from the Ferdowsi university web server. The study found that actual usage values differ for vendor-provided data and local usage data. Elsevier has got the highest usage degree in searches, sessions and downloads. Statistics also showed that a small number of journals satisfy significant amount of use while the majority of journals were used less frequent and some were never used at all. The users preferred the PDF rather than HTML format. The data in subject profile suggested that the provided e-resources were best suited to certain subjects. There was no correlation between IF and electronic journal use. Monitoring the usage of e-resources gained increasing importance for acquisition policy and budget decisions. The article provided information about local metrics for the six surveyed vendors/publishers, e.g. usage trends, requests per package, cost per use as related to the scientific specialty of the university.

  9. Electrochemical H2O2 biosensor composed of myoglobin on MoS2 nanoparticle-graphene oxide hybrid structure.

    Science.gov (United States)

    Yoon, Jinho; Lee, Taek; Bapurao G, Bharate; Jo, Jinhee; Oh, Byung-Keun; Choi, Jeong-Woo

    2017-07-15

    In this research, the electrochemical biosensor composed of myoglobin (Mb) on molybdenum disulfide nanoparticles (MoS 2 NP) encapsulated with graphene oxide (GO) was fabricated for the detection of hydrogen peroxide (H 2 O 2 ). Hybrid structure composed of MoS 2 NP and GO (GO@MoS 2 ) was fabricated for the first time to enhance the electrochemical signal of the biosensor. As a sensing material, Mb was introduced to fabricate the biosensor for H 2 O 2 detection. Formation and immobilization of GO@MoS 2 was confirmed by transmission electron microscopy, ultraviolet-visible spectroscopy, scanning electron microscopy, and scanning tunneling microscopy. Immobilization of Mb, and electrochemical property of biosensor were investigated by cyclic voltammetry and amperometric i-t measurements. Fabricated biosensor showed the electrochemical signal enhanced redox current as -1.86μA at an oxidation potential and 1.95μA at a reduction potential that were enhanced relative to those of electrode prepared without GO@MoS 2 . Also, this biosensor showed the reproducibility of electrochemical signal, and retained the property until 9 days from fabrication. Upon addition of H 2 O 2 , the biosensor showed enhanced amperometric response current with selectivity relative to that of the biosensor prepared without GO@MoS 2 . This novel hybrid material-based biosensor can suggest a milestone in the development of a highly sensitive detecting platform for biosensor fabrication with highly sensitive detection of target molecules other than H 2 O 2 . Copyright © 2016 Elsevier B.V. All rights reserved.

  10. A regenerative electrochemical biosensor for mercury(II) by using the insertion approach and dual-hairpin-based amplification

    International Nuclear Information System (INIS)

    Jia, Jing; Ling, Yu; Gao, Zhong Feng; Lei, Jing Lei; Luo, Hong Qun; Li, Nian Bing

    2015-01-01

    Highlights: • The dual-hairpin structure as a signal amplifier is label-free and handy. • The strategy uses the insertion approach to improve the hybridization efficiency. • This biosensor has a low detection limit (28 pM) for detection of Hg 2+ . • This biosensor can be easily regenerated by using L-cysteine. - Abstract: A simple and effective biosensor for Hg 2+ determination was investigated. The novel biosensor was prepared by the insertion approach that the moiety-labeled DNA inserted into a loosely packed cyclic-dithiothreitol (DTT) monolayer, improving the hybridization efficiency. Electrochemical impedance spectroscopy studies of two biosensors (single-hairpin and dual-hairpin structure DNA modified electrodes) used for Hg 2+ detection indicated that the dual-hairpin modified electrode had a larger electron transfer resistance change (ΔR ct ). Consequently, the dual-hairpin structure was used as a signal amplifier for the preparation of a selective Hg 2+ biosensor. This biosensor exhibited an excellent selectivity toward Hg 2+ over Cd 2+ , Pd 2+ , Co 2+ etc. Also, a linear relation was observed between the ΔR ct and Hg 2+ concentrations in a range from 0.1 nM to 5 μM with a detection limit of 28 pM under optimum conditions. Moreover, the biosensor can be reused by using L-cysteine and successfully applied for detecting Hg 2+ in real samples

  11. High-Sensitivity Temperature-Independent Silicon Photonic Microfluidic Biosensors

    Science.gov (United States)

    Kim, Kangbaek

    Optical biosensors that can precisely quantify the presence of specific molecular species in real time without the need for labeling have seen increased use in the drug discovery industry and molecular biology in general. Of the many possible optical biosensors, the TM mode Si biosensor is shown to be very attractive in the sensing application because of large field amplitude on the surface and cost effective CMOS VLSI fabrication. Noise is the most fundamental factor that limits the performance of sensors in development of high-sensitivity biosensors, and noise reduction techniques require precise studies and analysis. One such example stems from thermal fluctuations. Generally SOI biosensors are vulnerable to ambient temperature fluctuations because of large thermo-optic coefficient of silicon (˜2x10 -4 RIU/K), typically requiring another reference ring and readout sequence to compensate temperature induced noise. To address this problem, we designed sensors with a novel TM-mode shallow-ridge waveguide that provides both large surface amplitude for bulk and surface sensing. With proper design, this also provides large optical confinement in the aqueous cladding that renders the device athermal using the negative thermo-optic coefficient of water (~ --1x10-4RIU/K), demonstrating cancellation of thermo-optic effects for aqueous solution operation near 300K. Additional limitations resulting from mechanical actuator fluctuations, stability of tunable lasers, and large 1/f noise of lasers and sensor electronics can limit biosensor performance. Here we also present a simple harmonic feedback readout technique that obviates the need for spectrometers and tunable lasers. This feedback technique reduces the impact of 1/f noise to enable high-sensitivity, and a DSP lock-in with 256 kHz sampling rate can provide down to micros time scale monitoring for fast transitions in biomolecular concentration with potential for small volume and low cost. In this dissertation, a novel

  12. Use and User Perception of Electronic Information Resources: A Case Study of Siva Institute of Frontier Technology, India

    Directory of Open Access Journals (Sweden)

    Velmurugan Chandran

    2013-12-01

    Full Text Available The present study aims to explore the use and user perception of electronic resources in Siva Institute of Frontier Technology, India. A total number of 123 users were taken into account for the study through a questionnaire-based survey method. A well-structured questionnaire was designed and distributed to the selected 200 students and staff members. 123 copies of the questionnaires were returned dully filled in and the overall response rate was 61.50 percent. The questionnaire contained both open- and close-ended questions. The collected data were classified, analyzed, and tabulated by using simple statistical methods. This study covers the impact of electronic resources on students and faculty in their academic pursuit.

  13. Capacitive Biosensors and Molecularly Imprinted Electrodes.

    Science.gov (United States)

    Ertürk, Gizem; Mattiasson, Bo

    2017-02-17

    Capacitive biosensors belong to the group of affinity biosensors that operate by registering direct binding between the sensor surface and the target molecule. This type of biosensors measures the changes in dielectric properties and/or thickness of the dielectric layer at the electrolyte/electrode interface. Capacitive biosensors have so far been successfully used for detection of proteins, nucleotides, heavy metals, saccharides, small organic molecules and microbial cells. In recent years, the microcontact imprinting method has been used to create very sensitive and selective biorecognition cavities on surfaces of capacitive electrodes. This chapter summarizes the principle and different applications of capacitive biosensors with an emphasis on microcontact imprinting method with its recent capacitive biosensor applications.

  14. Challenges in the implementation of an electronic surveillance system in a resource-limited setting: Alerta, in Peru

    Directory of Open Access Journals (Sweden)

    Soto Giselle

    2008-11-01

    Full Text Available Abstract Background Infectious disease surveillance is a primary public health function in resource-limited settings. In 2003, an electronic disease surveillance system (Alerta was established in the Peruvian Navy with support from the U.S. Naval Medical Research Center Detachment (NMRCD. Many challenges arose during the implementation process, and a variety of solutions were applied. The purpose of this paper is to identify and discuss these issues. Methods This is a retrospective description of the Alerta implementation. After a thoughtful evaluation according to the Centers for Disease Control and Prevention (CDC guidelines, the main challenges to implementation were identified and solutions were devised in the context of a resource-limited setting, Peru. Results After four years of operation, we have identified a number of challenges in implementing and operating this electronic disease surveillance system. These can be divided into the following categories: (1 issues with personnel and stakeholders; (2 issues with resources in a developing setting; (3 issues with processes involved in the collection of data and operation of the system; and (4 issues with organization at the central hub. Some of the challenges are unique to resource-limited settings, but many are applicable for any surveillance system. For each of these challenges, we developed feasible solutions that are discussed. Conclusion There are many challenges to overcome when implementing an electronic disease surveillance system, not only related to technology issues. A comprehensive approach is required for success, including: technical support, personnel management, effective training, and cultural sensitivity in order to assure the effective deployment of an electronic disease surveillance system.

  15. RESEARCH OF INFLUENCE OF QUALITY OF ELECTRONIC EDUCATIONAL RESOURCES ON QUALITY OF TRAINING WITH USE OF DISTANCE TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    H. M. Kravtsov

    2013-03-01

    Full Text Available Communication improving of educational processes requires today new approaches to the management arrangements and forming of educational policy in the field of distance learning, which is based on the use of modern information and communication technologies. An important step in this process is the continuous monitoring of the development and implementation of information technology and, in particular, the distance learning systems in higher educational establishments. The main objective of the monitoring is the impact assessment on the development of distance learning following the state educational standards, curricula, methodical and technical equipment and other factors; factors revelation that influence the implementation and outcomes of distance learning; results comparison of educational institution functioning and distance education systems in order to determine the most efficient ways of its development. The paper presents the analysis results of the dependence of the quality of educational services on the electronic educational resources. Trends in educational services development was studied by comparing the quality influence of electronic educational resources on the quality of educational services of higher pedagogical educational institutions of Ukraine as of 2009-2010 and 2012-2013. Generally, the analysis of the survey results allows evaluating quality of the modern education services as satisfactory and it can be said that almost 70% of the success of their future development depends on the quality of the used electronic educational resources and distance learning systems in particular.

  16. Recent Development in Optical Fiber Biosensors

    Directory of Open Access Journals (Sweden)

    Catalina Bosch Ojeda

    2007-06-01

    Full Text Available Remarkable developments can be seen in the field of optical fibre biosensors in the last decade. More sensors for specific analytes have been reported, novel sensing chemistries or transduction principles have been introduced, and applications in various analytical fields have been realised. This review consists of papers mainly reported in the last decade and presents about applications of optical fiber biosensors. Discussions on the trends in optical fiber biosensor applications in real samples are enumerated.

  17. Biosensors based on nanomaterials and nanodevices

    CERN Document Server

    Li, Jun

    2013-01-01

    Biosensors Based on Nanomaterials and Nanodevices links interdisciplinary research from leading experts to provide graduate students, academics, researchers, and industry professionals alike with a comprehensive source for key advancements and future trends in nanostructured biosensor development. It describes the concepts, principles, materials, device fabrications, functions, system integrations, and applications of various types of biosensors based on signal transduction mechanisms, including fluorescence, photonic crystal, surface-enhanced Raman scattering, electrochemistry, electro-lumine

  18. Tracking the Flow of Resources in Electronic Waste - The Case of End-of-Life Computer Hard Disk Drives.

    Science.gov (United States)

    Habib, Komal; Parajuly, Keshav; Wenzel, Henrik

    2015-10-20

    Recovery of resources, in particular, metals, from waste flows is widely seen as a prioritized option to reduce their potential supply constraints in the future. The current waste electrical and electronic equipment (WEEE) treatment system is more focused on bulk metals, where the recycling rate of specialty metals, such as rare earths, is negligible compared to their increasing use in modern products, such as electronics. This study investigates the challenges in recovering these resources in the existing WEEE treatment system. It is illustrated by following the material flows of resources in a conventional WEEE treatment plant in Denmark. Computer hard disk drives (HDDs) containing neodymium-iron-boron (NdFeB) magnets were selected as the case product for this experiment. The resulting output fractions were tracked until their final treatment in order to estimate the recovery potential of rare earth elements (REEs) and other resources contained in HDDs. The results further show that out of the 244 kg of HDDs treated, 212 kg comprising mainly of aluminum and steel can be finally recovered from the metallurgic process. The results further demonstrate the complete loss of REEs in the existing shredding-based WEEE treatment processes. Dismantling and separate processing of NdFeB magnets from their end-use products can be a more preferred option over shredding. However, it remains a technological and logistic challenge for the existing system.

  19. HELP (INFORMATION ELECTRONIC RESOURCE "CHRONICLE OF ONU: DATES, FACTS, EVENTS": HISTORY OF UNIVERSITY IN INFORMATION SPACE

    Directory of Open Access Journals (Sweden)

    А. М. Гавриленко

    2016-03-01

    Object of research is the help information resource "The chronicle of the Odessa national university of I. I. Mechnikov: dates, facts, events". The main objective of our article – to state the main methodological bases of creation of information resource. One of advantages of information resource is possibility of continuous updating and replenishment by new information. Main objective of creation of this information resource is systematization of material on stories of the Odessa national university of I. I. Mechnikov from the date of his basis to the present, ensuring interactive access to information on the main dates, the most significant events in life of university. The base of research are sources on the history of university, chronology of historical development, formation of infrastructure, cadres and scientific researches. In information resource the main stages of development, functioning and transformation of the Odessa University are analyzed, information on its divisions is collected. For creation of this information resource in Scientific library the method of work was developed, the main selection criteria of data are allocated. This information resource have practical value for all who is interested in history of university, historians, scientists-researchers of history of science and the city of Odessa.

  20. A highly performing electrochemiluminescent biosensor for glucose based on a polyelectrolyte-chitosan modified electrode

    International Nuclear Information System (INIS)

    Dai Hong; Wu Xiaoping; Xu Huifeng; Wang Youmei; Chi Yuwu; Chen Guonan

    2009-01-01

    A highly performing ECL glucose biosensor was developed by immobilizing glucose oxidase (GOD) onto a membrane modified glassy carbon electrode, which was prepared by using poly(diallyldimethylammonium chloride) (PDDA) doped with chitosan. In order to obtain the optimal performance of the ECL biosensor, the composition of modified membranes and a series of measurement conditions were investigated. Under the optimal conditions, this ECL biosensor was able to detect glucose in the range of 0.5-4.0 x 10 4 nM with a detection limit of 0.1 nM (defined as the concentration that could be detected at the signal-to-noise ratio of 3). The relative standard deviation was 0.99% for 5 x 10 -8 mol/L glucose in repetitive measurements in the primary 12 potential cycles. This ECL biosensor offered the effectively improved stability of the electron transfer mediator and exhibited excellent properties for the ultrasensitive and selective determination of glucose with good reproducibility and stability. The present biosensor has also been used to determine the glucose concentrations in real serum samples. The recovery value for the assay of glucose ranged from 96.2 to 107% in the serum samples. The present biosensor displayed both specificity for glucose and retention of signal response even in a complex environment. Therefore, it provided an approach to the sensitive determination of glucose.

  1. Graphene based biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Gürel, Hikmet Hakan, E-mail: hhakan.gurel@kocaeli.edu.tr [Kocaeli University, Kocaeli (Turkey); Salmankurt, Bahadır [Sakarya University, Sakarya (Turkey)

    2016-03-25

    Nanometer-sized graphene as a 2D material has unique chemical and electronic properties. Because of its unique physical, chemical, and electronic properties, its interesting shape and size make it a promising nanomaterial in many biological applications. It is expected that biomaterials incorporating graphene will be developed for the graphene-based drug delivery systems and biomedical devices. The interactions of biomolecules and graphene are long-ranged and very weak. Development of new techniques is very desirable for design of bioelectronics sensors and devices. In this work, we present first-principles calculations within density functional theory to calculate effects of charging on nucleobases on graphene. It is shown that how modify structural and electronic properties of nucleobases on graphene by applied charging.

  2. Polyester Sulphonic Acid Interstitial Nanocomposite Platform for Peroxide Biosensor

    Directory of Open Access Journals (Sweden)

    Emmanuel I. Iwuoha

    2009-12-01

    Full Text Available A novel enzyme immobilization platform was prepared on a platinum disk working electrode by polymerizing aniline inside the interstitial pores of polyester sulphonic acid sodium salt (PESA. Scanning electron microscopy study showed the formation of homogeneous sulphonated polyaniline (PANI nanotubes (~90 nm and thermogravimetric analysis (TGA confirmed that the nanotubes were stable up to 230 °C. The PANI:PESA nanocomposite showed a quasi-reversible redox behaviour in phosphate buffer saline. Horseradish peroxidase (HRP was immobilized on to this modified electrode for hydrogen peroxide detection. The biosensor gave a sensitivity of 1.33 μA (μM-1 and a detection limit of 0.185 μM for H2O2. Stability experiments showed that the biosensor retained more than 64% of its initial sensitivity over four days of storage at 4 °C.

  3. Electrochemical DNA biosensors based on platinum nanoparticles combined carbon nanotubes

    International Nuclear Information System (INIS)

    Zhu Ningning; Chang Zhu; He Pingang; Fang Yuzhi

    2005-01-01

    Platinum nanoparticles were used in combination with multi-walled carbon nanotubes (MWCNTs) for fabricating sensitivity-enhanced electrochemical DNA biosensor. Multi-walled carbon nanotubes and platinum nanoparticles were dispersed in Nafion, which were used to fabricate the modification of the glassy carbon electrode (GCE) surface. Oligonucleotides with amino groups at the 5' end were covalently linked onto carboxylic groups of MWCNTs on the electrode. The hybridization events were monitored by differential pulse voltammetry (DPV) measurement of the intercalated daunomycin. Due to the ability of carbon nanotubes to promote electron-transfer reactions, the high catalytic activities of platinum nanoparticles for chemical reactions, the sensitivity of presented electrochemical DNA biosensors was remarkably improved. The detection limit of the method for target DNA was 1.0 x 10 -11 mol l -1

  4. Surface grafted polymer brushes: potential applications in dengue biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Baratela, Fernando Jose Costa; Higa, Olga Zazuco, E-mail: ozahiga@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Faria, Henrique Antonio Mendonca de; Queiroz, Alvaro Antonio Alencar de, E-mail: alencar@unifei.edu.br [Universidade Federal de Itajuba (UNIFEI), Itajuba, MG (Brazil). Instituto de Fisica e Quimica

    2013-07-01

    A polymer brush membrane-based ultrasensitive biosensor for dengue diagnosis was constructed using poly(hydroxyethyl methacrylate) (PHEMA) brushes immobilized onto low density polyethylene (LDPE) films. LDPE surface films were initially modified by Ar{sup +} ion irradiation to activate the polymer surface. Subsequently, graft polymerization of 2-hydroxyethyl methacrylate onto the activated LDPE surface was carried out under aqueous conditions to create patterned polymer brushes of PHEMA. The grafted PHEMA brushes were characterized by Fourier transform-infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and contact angle analysis. The SEM observations showed that selective surface activation with Ar+ implantation and graft polymerization on the selectively activated surface had occurred. The PHEMA brushes were electrically characterized in the presence of concentrations of human immunoglobulin (IgG). The proposed amperometric biosensor was successfully used for determination of IgG in physiologic samples with excellent responses. (author)

  5. Surface grafted polymer brushes: potential applications in dengue biosensors

    International Nuclear Information System (INIS)

    Baratela, Fernando Jose Costa; Higa, Olga Zazuco; Faria, Henrique Antonio Mendonca de; Queiroz, Alvaro Antonio Alencar de

    2013-01-01

    A polymer brush membrane-based ultrasensitive biosensor for dengue diagnosis was constructed using poly(hydroxyethyl methacrylate) (PHEMA) brushes immobilized onto low density polyethylene (LDPE) films. LDPE surface films were initially modified by Ar + ion irradiation to activate the polymer surface. Subsequently, graft polymerization of 2-hydroxyethyl methacrylate onto the activated LDPE surface was carried out under aqueous conditions to create patterned polymer brushes of PHEMA. The grafted PHEMA brushes were characterized by Fourier transform-infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and contact angle analysis. The SEM observations showed that selective surface activation with Ar+ implantation and graft polymerization on the selectively activated surface had occurred. The PHEMA brushes were electrically characterized in the presence of concentrations of human immunoglobulin (IgG). The proposed amperometric biosensor was successfully used for determination of IgG in physiologic samples with excellent responses. (author)

  6. Direct evidence of advantage of using nanosized zeolite Beta for ISFET-based biosensor construction

    International Nuclear Information System (INIS)

    Soy, Esin; Galioglu, Sezin; Soldatkin, Oleksandr O.; Dzyadevych, Sergei V.; Warzywoda, Juliusz; Sacco, Albert; Akata, Burcu

    2013-01-01

    Analytical characteristics of urease- and butyrylcholinesterase (BuChE)- based ion sensitive field-effect transistor (ISFET) biosensors were investigated by the incorporation of zeolite Beta nanoparticles with varying Si/Al ratios. The results obtained by the zeolite-modified ISFET transducers suggested that the Si/Al ratio strongly influenced the biosensor performances due to the electrostatic interactions among enzyme, substrate, and zeolite surface as well as the nature of the enzymatic reaction. Using relatively small nanoparticles (62.7 ± 10, 76.2 ± 10, and 77.1 ± 10 nm) rather than larger particles, that are widely used in the literature, allow us to produce more homogenous products which will give more control over the quantity of materials used on the electrode surface and ability to change solely Si/Al ratio without changing other parameters such as particle size, pore volume, and surface area. This should enable the investigation of the individual effect of changing acidic and electronic nature of this material on the biosensor characteristics. According to our results, high biosensor sensitivity is evident on nanosize and submicron size particles, with the former resulting in higher performance. The sensitivity of biosensors modified by zeolite particles is higher than that to the protein for both types of biosensors. Most significantly, our results show that the performance of constructed ISFET-type biosensors strongly depends on Si/Al ratio of employed zeolite Beta nanoparticles as well as the type of enzymatic reaction employed. All fabricated biosensors demonstrated high signal reproducibility and stability for both BuChE and urease.

  7. Synthesis and utilization of carbon nanotubes for fabrication of electrochemical biosensors

    International Nuclear Information System (INIS)

    Lawal, Abdulazeez T.

    2016-01-01

    Graphical abstract: Carbon nanotubes. - Highlights: • This review discusses synthesis and applications of carbon nanotubes sensors. • The review summarizes contributions of carbon nanotube to electrochemical biosensor. • Good electrical conductivity makes carbon nanotubes a good material for biosensors. • Carbon nanotubes promotes electron transfer that aids biosensing of biomolecules. - Abstract: This review summarizes the most recent contributions in the fabrication of carbon nanotubes-based electrochemical biosensors in recent years. It discusses the synthesis and application of carbon nanotubes to the assembly of carbon nanotube-based electrochemical sensors, its analytical performance and future expectations. An increasing number of reviews and publications involving carbon nanotubes sensors have been reported ever since the first design of carbon nanotube electrochemical biosensors. The large surface area and good electrical conductivity of carbon nanotubes allow them to act as “electron wire” between the redox center of an enzyme or protein and an electrode's surface, which make them very excellent material for the design of electrochemical biosensors. Carbon nanotubes promote the different rapid electron transfers that facilitate accurate and selective detection of cytochrome-c, β-nicotinamide adenine dinucleotide, hemoglobin and biomolecules, such as glucose, cholesterol, ascorbic acid, uric acid, dopamine pesticides, metals ions and hydrogen peroxide.

  8. Synthesis and utilization of carbon nanotubes for fabrication of electrochemical biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Lawal, Abdulazeez T., E-mail: abdul.lawal@yahoo.com

    2016-01-15

    Graphical abstract: Carbon nanotubes. - Highlights: • This review discusses synthesis and applications of carbon nanotubes sensors. • The review summarizes contributions of carbon nanotube to electrochemical biosensor. • Good electrical conductivity makes carbon nanotubes a good material for biosensors. • Carbon nanotubes promotes electron transfer that aids biosensing of biomolecules. - Abstract: This review summarizes the most recent contributions in the fabrication of carbon nanotubes-based electrochemical biosensors in recent years. It discusses the synthesis and application of carbon nanotubes to the assembly of carbon nanotube-based electrochemical sensors, its analytical performance and future expectations. An increasing number of reviews and publications involving carbon nanotubes sensors have been reported ever since the first design of carbon nanotube electrochemical biosensors. The large surface area and good electrical conductivity of carbon nanotubes allow them to act as “electron wire” between the redox center of an enzyme or protein and an electrode's surface, which make them very excellent material for the design of electrochemical biosensors. Carbon nanotubes promote the different rapid electron transfers that facilitate accurate and selective detection of cytochrome-c, β-nicotinamide adenine dinucleotide, hemoglobin and biomolecules, such as glucose, cholesterol, ascorbic acid, uric acid, dopamine pesticides, metals ions and hydrogen peroxide.

  9. Print and Electronic Resources: Usage Statistics at Guru Gobind Singh Indraprastha University Library

    Science.gov (United States)

    Kapoor, Kanta

    2010-01-01

    Purpose: The purpose of this paper is to quantify the use of electronic journals in comparison with the print collections in the Guru Gobind Singh Indraprastha University Library. Design/methodology/approach: A detailed analysis was made of the use of lending services, the Xerox facility and usage of electronic journals such as Science Direct,…

  10. Understanding intention to use electronic information resources: A theoretical extension of the technology acceptance model (TAM).

    Science.gov (United States)

    Tao, Donghua

    2008-11-06

    This study extended the Technology Acceptance Model (TAM) by examining the roles of two aspects of e-resource characteristics, namely, information quality and system quality, in predicting public health students' intention to use e-resources for completing research paper assignments. Both focus groups and a questionnaire were used to collect data. Descriptive analysis, data screening, and Structural Equation Modeling (SEM) techniques were used for data analysis. The study found that perceived usefulness played a major role in determining students' intention to use e-resources. Perceived usefulness and perceived ease of use fully mediated the impact that information quality and system quality had on behavior intention. The research model enriches the existing technology acceptance literature by extending TAM. Representing two aspects of e-resource characteristics provides greater explanatory information for diagnosing problems of system design, development, and implementation.

  11. Biosensors for DNA sequence detection

    Science.gov (United States)

    Vercoutere, Wenonah; Akeson, Mark

    2002-01-01

    DNA biosensors are being developed as alternatives to conventional DNA microarrays. These devices couple signal transduction directly to sequence recognition. Some of the most sensitive and functional technologies use fibre optics or electrochemical sensors in combination with DNA hybridization. In a shift from sequence recognition by hybridization, two emerging single-molecule techniques read sequence composition using zero-mode waveguides or electrical impedance in nanoscale pores.

  12. Plasmonic Nanostructures for Biosensor Applications

    Science.gov (United States)

    Gadde, Akshitha

    Improving the sensitivity of existing biosensors is an active research topic that cuts across several disciplines, including engineering and biology. Optical biosensors are the one of the most diverse class of biosensors which can be broadly categorized into two types based on the detection scheme: label-based and label-free detection. In label-based detection, the target bio-molecules are labeled with dyes or tags that fluoresce upon excitation, indicating the presence of target molecules. Label-based detection is highly-sensitive, capable of single molecule detection depending on the detector type used. One method of improving the sensitivity of label-based fluorescence detection is by enhancement of the emission of the labels by coupling them with metal nanostructures. This approach is referred as plasmon-enhanced fluorescence (PEF). PEF is achieved by increasing the electric field around the nano metal structures through plasmonics. This increased electric field improves the enhancement from the fluorophores which in turn improves the photon emission from the fluorophores which, in turn, improves the limit of detection. Biosensors taking advantage of the plasmonic properties of metal films and nanostructures have emerged an alternative, low-cost, high sensitivity method for detecting labeled DNA. Localized surface plasmon resonance (LSPR) sensors employing noble metal nanostructures have recently attracted considerable attention as a new class of plasmonic nanosensors. In this work, the design, fabrication and characterization of plasmonic nanostructures is carried out. Finite difference time domain (FDTD) simulations were performed using software from Lumerical Inc. to design a novel LSPR structure that exhibit resonance overlapping with the absorption and emission wavelengths of quantum dots (QD). Simulations of a composite Au/SiO2 nanopillars on silicon substrate were performed using FDTD software to show peak plasmonic enhancement at QD emission wavelength

  13. Conducting polymer based biomolecular electronic devices

    Indian Academy of Sciences (India)

    Conducting polymers; LB films; biosensor microactuators; monolayers. ... have been projected for applications for a wide range of biomolecular electronic devices such as optical, electronic, drug-delivery, memory and biosensing devices.

  14. Building and Managing Electronic Resources in Digital Era in India with Special Reference to IUCAA and NIV, Pune: A Comparative Case Study

    Science.gov (United States)

    Sahu, H. K.; Singh, S. N.

    2015-04-01

    This paper discusses and presents a comparative case study of two libraries in Pune, India, Inter-University Centre for Astronomy and Astrophysics and Information Centre and Library of National Institute of Virology (Indian Council of Medical Research). It compares how both libraries have managed their e-resource collections, including acquisitions, subscriptions, and consortia arrangements, while also developing a collection of their own resources, including pre-prints and publications, video lectures, and other materials in an institutional repository. This study illustrates how difficult it is to manage electronic resources in a developing country like India, even though electronic resources are used more than print resources. Electronic resource management can be daunting, but with a systematic approach, various problems can be solved, and use of the materials will be enhanced.

  15. The level of the usage of the human resource information system and electronic recruitment in Croatian companies

    Directory of Open Access Journals (Sweden)

    Snježana Pivac

    2014-12-01

    Full Text Available Performing business according to contemporary requirements influences companies for continuous usage of modern managerial tools, such as a human resource information system (HRIS and electronic recruitment (ER. Human resources have been recognised as curtail resources and the main source of a competitive advantage in creation of successful business performance. In order to attract and select the top employees, companies use quality information software for attracting internal ones, and electronic recruitment for attracting the best possible external candidates. The main aim of this paper is to research the level of the usage of HRIS and ER within medium-size and large Croatian companies. Moreover, the additional aim of this paper is to evaluate the relationship among the usage of these modern managerial tools and the overall success of human resource management within these companies. For the purpose of this paper, primary and secondary research has been conducted in order to reveal the level of the usage of HRIS and ER as well as the overall success of human resource management in Croatian companies. The companies’ classification (HRIS and ER is done by using the non-hierarchical k-means cluster method as well as the nonparametric Kruskal Wallis test. Further, the companies are ranked by the multicriteria PROMETHEE method. Relevant nonparametric tests are used for testing the overall companies’ HRM. Finally, binary logistic regression is estimated, relating binary variable HRM and HRIS development. After detailed research, it can be concluded that large Croatian companies apply HRIS in majority (with a positive relation to HRM performance, but still require certain degrees of its development.

  16. Electro chemiluminescence Biosensor Based on Thioglycolic Acid-Capped Cd Se QDs for Sensing Glucose

    International Nuclear Information System (INIS)

    Jung, E. Y.; Ye, J. H.; Choi, S. H.; Jung, S. H.

    2016-01-01

    In order to detect low level glucose concentration, an electro chemiluminescence (ECL) biosensor based on TGA-capped Cd Se quantum dots (QDs) was fabricated by the immobilization of Cd Se QDs after modifying the surface of a glassy carbon electrode (GCE) with 4-amino thiophenol diazonium salts by the electrochemical method. For the detection of glucose concentration, glucose oxidase (GOD) was immobilized onto the fabricated Cd Se QDs-modified electrode. The fabricated ECL biosensor based on TGA-capped Cd Se QDs was characterized using a scanning electron microscope (SEM), UV-vis spectrophotometry, transmission electron microscopy (TEM), a fluorescence spectrometer (PL), and cyclic voltammetry (CV). The fabricated ECL biosensor based on TGA-capped Cd Se QDs is suitable for the detection of glucose concentrations in real human blood samples.

  17. Electrochemiluminescence Biosensor Based on Thioglycolic Acid-Capped CdSe QDs for Sensing Glucose

    Directory of Open Access Journals (Sweden)

    Eun-Young Jung

    2016-01-01

    Full Text Available In order to detect low level glucose concentration, an electrochemiluminescence (ECL biosensor based on TGA-capped CdSe quantum dots (QDs was fabricated by the immobilization of CdSe QDs after modifying the surface of a glassy carbon electrode (GCE with 4-aminothiophenol diazonium salts by the electrochemical method. For the detection of glucose concentration, glucose oxidase (GOD was immobilized onto the fabricated CdSe QDs-modified electrode. The fabricated ECL biosensor based on TGA-capped CdSe QDs was characterized using a scanning electron microscope (SEM, UV-vis spectrophotometry, transmission electron microscopy (TEM, a fluorescence spectrometer (PL, and cyclic voltammetry (CV. The fabricated ECL biosensor based on TGA-capped CdSe QDs is suitable for the detection of glucose concentrations in real human blood samples.

  18. Antibody orientation on biosensor surfaces: a minireview

    NARCIS (Netherlands)

    Trilling, A.K.; Beekwilder, M.J.; Zuilhof, H.

    2013-01-01

    Detection elements play a key role in analyte recognition in biosensors. Therefore, detection elements with high analyte specificity and binding strength are required. While antibodies (Abs) have been increasingly used as detection elements in biosensors, a key challenge remains – the immobilization

  19. A New Laccase Based Biosensor for Tartrazine

    Directory of Open Access Journals (Sweden)

    Siti Zulaikha Mazlan

    2017-12-01

    Full Text Available Laccase enzyme, a commonly used enzyme for the construction of biosensors for phenolic compounds was used for the first time to develop a new biosensor for the determination of the azo-dye tartrazine. The electrochemical biosensor was based on the immobilization of laccase on functionalized methacrylate-acrylate microspheres. The biosensor membrane is a composite of the laccase conjugated microspheres and gold nanoparticles (AuNPs coated on a carbon-paste screen-printed electrode. The reaction involving tartrazine can be catalyzed by laccase enzyme, where the current change was measured by differential pulse voltammetry (DPV at 1.1 V. The anodic peak current was linear within the tartrazine concentration range of 0.2 to 14 μM (R2 = 0.979 and the detection limit was 0.04 μM. Common food ingredients or additives such as glucose, sucrose, ascorbic acid, phenol and sunset yellow did not interfere with the biosensor response. Furthermore, the biosensor response was stable up to 30 days of storage period at 4 °C. Foods and beverage were used as real samples for the biosensor validation. The biosensor response to tartrazine showed no significant difference with a standard HPLC method for tartrazine analysis.

  20. Background reduction in a young interferometer biosensor

    NARCIS (Netherlands)

    Mulder, H. K P; Subramaniam, V.; Kanger, J. S.

    2014-01-01

    Integrated optical Young interferometer (IOYI) biosensors are among the most sensitive label-free biosensors. Detection limits are in the range of 20 fg/mm2. The applicability of these sensors is however strongly hampered by the large background that originates from both bulk refractive index

  1. A New Laccase Based Biosensor for Tartrazine.

    Science.gov (United States)

    Mazlan, Siti Zulaikha; Lee, Yook Heng; Hanifah, Sharina Abu

    2017-12-09

    Laccase enzyme, a commonly used enzyme for the construction of biosensors for phenolic compounds was used for the first time to develop a new biosensor for the determination of the azo-dye tartrazine. The electrochemical biosensor was based on the immobilization of laccase on functionalized methacrylate-acrylate microspheres. The biosensor membrane is a composite of the laccase conjugated microspheres and gold nanoparticles (AuNPs) coated on a carbon-paste screen-printed electrode. The reaction involving tartrazine can be catalyzed by laccase enzyme, where the current change was measured by differential pulse voltammetry (DPV) at 1.1 V. The anodic peak current was linear within the tartrazine concentration range of 0.2 to 14 μM ( R ² = 0.979) and the detection limit was 0.04 μM. Common food ingredients or additives such as glucose, sucrose, ascorbic acid, phenol and sunset yellow did not interfere with the biosensor response. Furthermore, the biosensor response was stable up to 30 days of storage period at 4 °C. Foods and beverage were used as real samples for the biosensor validation. The biosensor response to tartrazine showed no significant difference with a standard HPLC method for tartrazine analysis.

  2. MendelWeb: An Electronic Science/Math/History Resource for the WWW.

    Science.gov (United States)

    Blumberg, Roger B.

    This paper describes a hypermedia resource, called MendelWeb that integrates elementary biology, discrete mathematics, and the history of science. MendelWeb is constructed from Gregor Menders 1865 paper, "Experiments in Plant Hybridization". An English translation of Mendel's paper, which is considered to mark the birth of classical and…

  3. Helping Patrons Find Locally Held Electronic Resources: An Interlibrary Loan Perspective

    Science.gov (United States)

    Johnston, Pamela

    2016-01-01

    The University of North Texas Libraries provide extensive online access to academic journals through major vendor databases. As illustrated by interlibrary loan borrowing requests for items held in our databases, patrons often have difficulty navigating the available resources. In this study, the Interlibrary Loan staff used data gathered from the…

  4. QR Codes as Finding Aides: Linking Electronic and Print Library Resources

    Science.gov (United States)

    Kane, Danielle; Schneidewind, Jeff

    2011-01-01

    As part of a focused, methodical, and evaluative approach to emerging technologies, QR codes are one of many new technologies being used by the UC Irvine Libraries. QR codes provide simple connections between print and virtual resources. In summer 2010, a small task force began to investigate how QR codes could be used to provide information and…

  5. Prussian Blue acts as a mediator in a reagentless cytokinin biosensor

    International Nuclear Information System (INIS)

    Kowalska, Marta; Tian Faming; Smehilova, Maria; Galuszka, Petr; Frebort, Ivo; Napier, Richard; Dale, Nicholas

    2011-01-01

    Highlights: · An electrochemical biosensor for detection of the plant hormone cytokinin. · Constitutive expression system for large-scale protein production. · CKX enzyme entrapment in sol-gel film on the surface of a PrB-modified electrode. · Prussian Blue as an electron mediator between the enzyme and the electrode. · The biosensor was sensitive to micromolar concentrations of several cytokinins. - Abstract: An electrochemical biosensor for detection of the plant hormone cytokinin is introduced. Cytokinin homeostasis in tissues of many lower and higher plants is controlled largely by the activity of cytokinin dehydrogenase (CKX, EC 1.5.99.12) that catalyzes an irreversible cleavage of N 6 -side chain of cytokinins. Expression of Arabidopsis thaliana CKX2 from Pichia pastoris was used to prepare purified AtCKX2 as the basis of the cytokinin biosensor. Prussian Blue (PrB) was electrodeposited on Pt microelectrodes prior to deposition of the enzyme in a sol-gel matrix. The biosensor gave amperometric responses to several cytokinins. These responses depended on the presence of both the enzyme and the Prussian Blue. Thus Prussian Blue must act as an electron mediator between the FAD centre in CKX2 and the Pt surface.

  6. Study on a hydrogen peroxide biosensor based on horseradish peroxidase/GNPs-thionine/chitosan

    International Nuclear Information System (INIS)

    Kang Xiaobin; Pang Guangchang; Liang Xinyi; Wang Meng; Liu Jing; Zhu Weiming

    2012-01-01

    Highlights: ► Glutaraldehyde was used as the bridge linking agent to covalently bonded thionine in chitosan, which is more stable and could effectively prevalent leakage of the electronic mediator. ► The effect of GNPs adsorbed HRP was first accurately characterized by bio-layer interferometry using the ForteBio Octer system. ► The application of self-assembly technology increases the biosensor stability. - Abstract: A novel hydrogen peroxide biosensor based on horseradish peroxidase/GNPs-thionine/chitosan has been developed. Gold nanoparticles fixed with horseradish peroxidase were adsorbed on glassy carbon electrode by the chitosan which cross-linked with the electron mediator of horseradish peroxidase as the bridge linking agent. The assembly procedures were monitored by UV–visible spectral scanning, bio-layer interferometry, cyclic voltammetric and alternating current impedance. The chronoamperometry was used to measure hydrogen peroxide. The hydrogen peroxide biosensor linear range of detection is 1 × 10 −7 –1 × 10 −4 mol/L, detection limit up to 5.0 × 10 −8 mol/L. Moreover the stability, reproducibility and selectivity of the biosensor were also studied and the results confirmed that the biosensor exhibit fast response to hydrogen peroxide and possess high sensitivity, good reproducibility and long-term stability.

  7. Biosensors Based on Urease Adsorbed on Nickel, Platinum, and Gold Conductometric Transducers Modified with Silicalite and Nanozeolites

    Science.gov (United States)

    Kucherenko, Ivan S.; Soldatkin, Oleksandr O.; Kasap, Berna Ozansoy; Kurç, Burcu Akata; Melnyk, Volodymir G.; Semenycheva, Lyudmila M.; Dzyadevych, Sergei V.; Soldatkin, Alexei P.

    This work describes urease-based conductometric biosensors that were created using nontypical method of urease immobilization via adsorption on micro- and nanoporous particles: silicalite and nanocrystalline zeolites Beta (BEA) and L. Conductometric transducers with nickel, gold, and platinum interdigitated electrodes were used. Active regions of the nickel transducers were modified with microparticles using two procedures—spin coating and drop coating. Gold and platinum transducers were modified with silicalite using drop coating since it was more effective. Scanning electron microscopy was used to evaluate effectiveness of these procedures. The procedure of spin coating produced more uniform layers of particles (and biosensors had good reproducibility of preparation), but it was more complicated, drop coating was easier and led to formation of a bulk of particles; thus, biosensors had bigger sensitivity but worse reproducibility of preparation. Urease was immobilized onto transducers modified with particles by physical adsorption. Analytical characteristics of the obtained biosensors for determination of urea (calibration curves, sensitivity, limit of detection, linear concentration range, noise of responses, reproducibility of signal during a day, and operational stability during 3 days) were compared. Biosensors with all three particles deposited by spin coating showed similar characteristics; however, silicalite was a bit more effective. Biosensors based on nickel transducers modified by drop coating had better characteristics in comparison with modification by spin coating (except reproducibility of preparation). Transducers with gold electrodes showed best characteristics while creating biosensors, platinum electrodes were slightly inferior to them, and nickel electrodes were the worst.

  8. Applications of polymers for biomolecule immobilization in electrochemical biosensors

    International Nuclear Information System (INIS)

    Teles, F.R.R.; Fonseca, L.P.

    2008-01-01

    Polymers are becoming inseparable from biomolecule immobilization strategies and biosensor platforms. Their original role as electrical insulators has been progressively substituted by their electrical conductive abilities, which opens a new and broad scope of applications. In addition, recent advances in diagnostic chips and microfluidic systems, together with the requirements of mass-production technologies, have raised the need to replace glass by polymeric materials, which are more suitable for production through simple manufacturing processes. Conducting polymers (CPs), in particular, are especially amenable for electrochemical biosensor development for providing biomolecule immobilization and for rapid electron transfer. It is expected that the combination of known polymer substrates, but also new transducing and biocompatible interfaces, with nanobiotechnological structures, like nanoparticles, carbon nanotubes (CNTs) and nanoengineered 'smart' polymers, may generate composites with new and interesting properties, providing higher sensitivity and stability of the immobilized molecules, thus constituting the basis for new and improved analytical devices for biomedical and other applications. This review covers the state-of-the-art and main novelties about the use of polymers for immobilization of biomolecules in electrochemical biosensor platforms

  9. Nanomaterials based biosensors for cancer biomarker detection

    International Nuclear Information System (INIS)

    Malhotra, Bansi D; Kumar, Saurabh; Pandey, Chandra Mouli

    2016-01-01

    Biosensors have enormous potential to contribute to the evolution of new molecular diagnostic techniques for patients suffering with cancerous diseases. A major obstacle preventing faster development of biosensors pertains to the fact that cancer is a highly complex set of diseases. The oncologists currently rely on a few biomarkers and histological characterization of tumors. Some of the signatures include epigenetic and genetic markers, protein profiles, changes in gene expression, and post-translational modifications of proteins. These molecular signatures offer new opportunities for development of biosensors for cancer detection. In this context, conducting paper has recently been found to play an important role towards the fabrication of a biosensor for cancer biomarker detection. In this paper we will focus on results of some of the recent studies obtained in our laboratories relating to fabrication and application of nanomaterial modified paper based biosensors for cancer biomarker detection. (paper)

  10. Functionalized Palladium Nanoparticles for Hydrogen Peroxide Biosensor

    Directory of Open Access Journals (Sweden)

    H. Baccar

    2011-01-01

    Full Text Available We present a comparison between two biosensors for hydrogen peroxide (H2O2 detection. The first biosensor was developed by the immobilization of Horseradish Peroxidase (HRP enzyme on thiol-modified gold electrode. The second biosensor was developed by the immobilization of cysteamine functionalizing palladium nanoparticles on modified gold surface. The amino groups can be activated with glutaraldehyde for horseradish peroxidase immobilization. The detection of hydrogen peroxide was successfully observed in PBS for both biosensors using the cyclic voltammetry and the chronoamperometry techniques. The results show that the limit detection depends on the large surface-to-volume ratio attained with palladium nanoparticles. The second biosensor presents a better detection limit of 7.5 μM in comparison with the first one which is equal to 75 μM.

  11. Eavesdropping on Electronic Guidebooks: Observing Learning Resources in Shared Listening Environments.

    Science.gov (United States)

    Woodruff, Allison; Aoki, Paul M.; Grinter, Rebecca E.; Hurst, Amy; Szymanski, Margaret H.; Thornton, James D.

    This paper describes an electronic guidebook, "Sotto Voce," that enables visitors to share audio information by eavesdropping on each others guidebook activity. The first section discusses the design and implementation of the guidebook device, key aspects of its user interface, the design goals for the audio environment, the eavesdropping…

  12. Electrochemical biosensors in pharmaceutical analysis

    Directory of Open Access Journals (Sweden)

    Eric de Souza Gil

    2010-09-01

    Full Text Available Given the increasing demand for practical and low-cost analytical techniques, biosensors have attracted attention for use in the quality analysis of drugs, medicines, and other analytes of interest in the pharmaceutical area. Biosensors allow quantification not only of the active component in pharmaceutical formulations, but also the analysis of degradation products and metabolites in biological fluids. Thus, this article presents a brief review of biosensor use in pharmaceutical analysis, focusing on enzymatic electrochemical sensors.Em virtude do aumento da demanda por técnicas analíticas simples e de baixo custo, os biossensores têm atraído a atenção para a análise de fármacos, medicamentos e outros analitos de interesse em controle de qualidade de medicamentos. Os biossensores permitem a quantificação não somente de princípio ativo em formulações farmacêuticas, mas também de produtos de degradação e metabólitos em fluídos biológicos, bem como análise de amostras de interesse clínico e industrial, além de possibilitar a determinação de enantiômeros. Desta forma, este artigo objetiva fazer uma breve revisão a respeito do emprego de biossensores em análise farmacêutica, com ênfase em sensores eletroquímicos enzimáticos.

  13. Development and evolution of The Knowledge Hub for Pathology and related electronic resources.

    Science.gov (United States)

    Hardwick, David F; Sinard, John; Silva, Fred

    2011-06-01

    The Knowledge Hub for Pathology was created to provide authenticated and validated knowledge for United States and Canadian Academy of Pathology members and pathologists worldwide with access to the Web. Using the material presented at the annual meeting of the United States and Canadian Academy of Pathology with existing selection and review procedures ensured that these criteria were met without added costly procedures. Further submissions for courses and research papers are provided in electronic format and funded by universities and hospitals for their creation; thus, the principal costs borne by the United States and Canadian Academy of Pathology are Web site-posting costs. Use has escalated rapidly from 2 million hits in 2002 to 51 million in 2009 with use by 35,000 pathologists from now a total of 180 countries. This true "freemium" model is a successful process as are more traditional continuing professional development course structures such as Anatomic Pathology Electronic Case Series, a "premium" model for learning electronically also sponsored by the United States and Canadian Academy of Pathology. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. A sensitive glucose biosensor based on Ag@C core–shell matrix

    International Nuclear Information System (INIS)

    Zhou, Xuan; Dai, Xingxin; Li, Jianguo; Long, Yumei; Li, Weifeng; Tu, Yifeng

    2015-01-01

    Nano-Ag particles were coated with colloidal carbon (Ag@C) to improve its biocompatibility and chemical stability for the preparation of biosensor. The core–shell structure was evidenced by transmission electron microscope (TEM) and the Fourier transfer infrared (FTIR) spectra revealed that the carbon shell is rich of function groups such as − OH and − COOH. The as-prepared Ag@C core–shell structure can offer favorable microenvironment for immobilizing glucose oxidase and the direct electrochemistry process of glucose oxidase (GOD) at Ag@C modified glassy carbon electrode (GCE) was realized. The modified electrode exhibited good response to glucose. Under optimum experimental conditions the biosensor linearly responded to glucose concentration in the range of 0.05–2.5 mM, with a detection limit of 0.02 mM (S/N = 3). The apparent Michaelis–Menten constant (K M app ) of the biosensor is calculated to be 1.7 mM, suggesting high enzymatic activity and affinity toward glucose. In addition, the GOD-Ag@C/Nafion/GCE shows good reproducibility and long-term stability. These results suggested that core–shell structured Ag@C is an ideal matrix for the immobilization of the redox enzymes and further the construction of the sensitive enzyme biosensor. - Highlights: • Enhanced direct electrochemistry of GOD was achieved at Ag@C modified electrode. • A novel glucose biosensor based on Ag@C core–shell structure was developed. • The designed GOD-Ag@C/Nafion/GCE biosensor showed favorable analysis properties. • The biosensor is easy to prepare and can be applied for real sample assay

  15. A sensitive glucose biosensor based on Ag@C core–shell matrix

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xuan; Dai, Xingxin; Li, Jianguo [College of Chemistry, Chemical engineering and Materials Science, Soochow University, Suzhou, Jiangsu 215123 (China); Long, Yumei, E-mail: yumeilong@suda.edu.cn [College of Chemistry, Chemical engineering and Materials Science, Soochow University, Suzhou, Jiangsu 215123 (China); The Key Lab of Health Chemistry and Molecular Diagnosis of Suzhou (China); Li, Weifeng, E-mail: liweifeng@suda.edu.cn [College of Chemistry, Chemical engineering and Materials Science, Soochow University, Suzhou, Jiangsu 215123 (China); Tu, Yifeng [College of Chemistry, Chemical engineering and Materials Science, Soochow University, Suzhou, Jiangsu 215123 (China); The Key Lab of Health Chemistry and Molecular Diagnosis of Suzhou (China)

    2015-04-01

    Nano-Ag particles were coated with colloidal carbon (Ag@C) to improve its biocompatibility and chemical stability for the preparation of biosensor. The core–shell structure was evidenced by transmission electron microscope (TEM) and the Fourier transfer infrared (FTIR) spectra revealed that the carbon shell is rich of function groups such as − OH and − COOH. The as-prepared Ag@C core–shell structure can offer favorable microenvironment for immobilizing glucose oxidase and the direct electrochemistry process of glucose oxidase (GOD) at Ag@C modified glassy carbon electrode (GCE) was realized. The modified electrode exhibited good response to glucose. Under optimum experimental conditions the biosensor linearly responded to glucose concentration in the range of 0.05–2.5 mM, with a detection limit of 0.02 mM (S/N = 3). The apparent Michaelis–Menten constant (K{sub M}{sup app}) of the biosensor is calculated to be 1.7 mM, suggesting high enzymatic activity and affinity toward glucose. In addition, the GOD-Ag@C/Nafion/GCE shows good reproducibility and long-term stability. These results suggested that core–shell structured Ag@C is an ideal matrix for the immobilization of the redox enzymes and further the construction of the sensitive enzyme biosensor. - Highlights: • Enhanced direct electrochemistry of GOD was achieved at Ag@C modified electrode. • A novel glucose biosensor based on Ag@C core–shell structure was developed. • The designed GOD-Ag@C/Nafion/GCE biosensor showed favorable analysis properties. • The biosensor is easy to prepare and can be applied for real sample assay.

  16. A Conductive Porous Structured Chitosan-grafted Polyaniline Cryogel for use as a Sialic Acid Biosensor

    International Nuclear Information System (INIS)

    Fatoni, Amin; Numnuam, Apon; Kanatharana, Proespichaya; Limbut, Warakorn; Thavarungkul, Panote

    2014-01-01

    Highlights: • A novel chitosan grafted polyaniline cryogel was used as support for a highly stable and sensitive biosensor. • The use of two enzymes mediated with ferrocene showed a high selectivity for sialic acid. • The biosensor provided a rapid sialic acid detection in blood. - Abstract: A porous conductive supporting material base on chitosan grafted polyaniline (CPANI) cryogel was developed for the fabrication of a sialic acid biosensor. Two enzymes, N-acetylneuraminic acid aldolase (NAL) and pyruvate oxidase (PYO), were employed together with an electrochemical detector. The electron transfer was further enhanced by using multiwalled carbon nanotubes (MWCNTs) and mediated by ferrocene (Fc) entrapped in the cryogel pores wall. A sialic acid derived electroactive product was detected amperometrically in a flow injection system. The fabricated sialic acid biosensor provided excellent analytical performances with a wide linear range of 0.025 to 15.0 mM and a limit of detection of 18 μM. Under the low applied potential of 0.20 V versus a Ag/AgCl, common electroactive interfering compounds such as ascorbic acid, uric acid and pyruvic acid were not detected and they have no effect on the analysis of sialic acid. The fabricated sialic acid biosensor also demonstrated a high stability after up to 100 injections. The reliability of the biosensor to detect sialic acid in blood plasma was in good agreement (P > 0.05) with a standard periodic-resorcinol spectrophotometric method. This easy to prepare conductive and biocompatible porous structure should be a prospective supporting material for biosensor development

  17. An Exploratory study on the use of LibAnswers to Resolve, Track and Monitor Electronic Resources Issues: The KAUST Library experience

    KAUST Repository

    Ramli, Rindra M.

    2017-01-01

    An Exploratory study on KAUST library use of LibAnswers in resolving electronic resources questions received in LibAnswers. It describes the findings of the questions received in LibAnswers. The author made suggestions based on the findings to improve the reference services in responding to e-resources questions.

  18. An Exploratory study on the use of LibAnswers to Resolve, Track and Monitor Electronic Resources Issues: The KAUST Library experience

    KAUST Repository

    Ramli, Rindra M.

    2017-05-03

    An Exploratory study on KAUST library use of LibAnswers in resolving electronic resources questions received in LibAnswers. It describes the findings of the questions received in LibAnswers. The author made suggestions based on the findings to improve the reference services in responding to e-resources questions.

  19. Designing a model of electronic human resource management’s implementation at the Ministry of Communications and Information Technology

    Directory of Open Access Journals (Sweden)

    Mirali Seyednaghavi

    2017-06-01

    Full Text Available : In the first phase of this study a model for electronic human resource management in government agencies based on new public services was explored by using software MAXQDA, then in the second phase, relationship between the elements of the theory were tested using software Smart PLS2. So the aim of this study is to design a model of electronic human resource management’s implementation at the Ministry of Communications and Information Technology. In this regard, according to Strauss and Corbin’s structured plan, five hypotheses were tested. Quantitative data analysis indicates that the pressures of the policies and global perspectives cause to move toward e-HRM. Among the contextual conditions macro structural mechanisms, considerations of actors, governance considerations have a significant impact on the strategy of new public services and therefore lead to the consequences of its implementation in public organizations. The findings suggest that e-HRM does not have a positive and meaningful impact on new public services, and in our country, although the recent political developments have somehow removed the gap between public policy makers, administrators, and the public, but there is still a long way to go.

  20. Preference and Use of Electronic Information and Resources by Blind/Visually Impaired in NCR Libraries in India

    Directory of Open Access Journals (Sweden)

    Shailendra Kumar

    2013-06-01

    Full Text Available This paper aims to determine the preference and use of electronic information and resources by blind/visually impaired users in the leading National Capital Region (NCR libraries of India. Survey methodology has been used as the basic research tool for data collection with the help of questionnaires. The 125 in total users surveyed in all the five libraries were selected randomly on the basis of willingness of the users with experience of working in digital environments to participate in the survey. The survey results were tabulated and analyzed with descriptive statistics methods using Excel software and 'Stata version 11'. The findings reveal that ICT have a positive impact in the lives of people with disabilities as it helps them to work independently and increases the level of confidence among them. The Internet is the most preferred medium of access to information among the majority of blind/visually impaired users. The 'Complexity of content available on the net' is found as the major challenge faced during Internet use by blind users of NCR libraries. 'Audio books on CDs/DVDs and DAISY books' are the most preferred electronic resources among the majority of blind/visually impaired users. This study will help the library professionals and organizations/institutions serving people with disabilities to develop effective library services for blind/visually impaired users in the digital environment on the basis of findings on information usage behavior in the study.

  1. Investigation of cleaning and regeneration methods for reliable construction of DNA cantilever biosensors

    DEFF Research Database (Denmark)

    Quan, Xueling; Yi, Sun; Heiskanen, Arto

    to clean and regenerate the sensing surface of cantilever biosensors. Perchloric acid potential sweep, potassium hydroxide-hydrogen peroxide, and piranha cleaning are investigated here. Peak-current potential differences from cyclic voltammetry, X-ray photo-electron spectroscopy and fluorescence detection...

  2. Internet and electronic resources for inflammatory bowel disease: a primer for providers and patients.

    Science.gov (United States)

    Fortinsky, Kyle J; Fournier, Marc R; Benchimol, Eric I

    2012-06-01

    Patients with inflammatory bowel disease (IBD) are increasingly turning to the Internet to research their condition and engage in discourse on their experiences. This has resulted in new dynamics in the relationship between providers and their patients, with misinformation and advertising potentially presenting barriers to the cooperative patient-provider partnership. This article addresses important issues of online IBD-related health information and social media activity, such as quality, reliability, objectivity, and privacy. We reviewed the medical literature on the quality of online information provided to IBD patients, and summarized the most commonly accessed Websites related to IBD. We also assessed the activity on popular social media sites (such as Facebook, Twitter, and YouTube), and evaluated currently available applications for use by IBD patients and providers on mobile phones and tablets. Through our review of the literature and currently available resources, we developed a list of recommended online resources to strengthen patient participation in their care by providing reliable, comprehensive educational material. Copyright © 2011 Crohn's & Colitis Foundation of America, Inc.

  3. Comparative advantages of mechanical biosensors.

    Science.gov (United States)

    Arlett, J L; Myers, E B; Roukes, M L

    2011-04-01

    Mechanical interactions are fundamental to biology. Mechanical forces of chemical origin determine motility and adhesion on the cellular scale, and govern transport and affinity on the molecular scale. Biological sensing in the mechanical domain provides unique opportunities to measure forces, displacements and mass changes from cellular and subcellular processes. Nanomechanical systems are particularly well matched in size with molecular interactions, and provide a basis for biological probes with single-molecule sensitivity. Here we review micro- and nanoscale biosensors, with a particular focus on fast mechanical biosensing in fluid by mass- and force-based methods, and the challenges presented by non-specific interactions. We explain the general issues that will be critical to the success of any type of next-generation mechanical biosensor, such as the need to improve intrinsic device performance, fabrication reproducibility and system integration. We also discuss the need for a greater understanding of analyte-sensor interactions on the nanoscale and of stochastic processes in the sensing environment.

  4. Biosensor approach to psychopathology classification.

    Directory of Open Access Journals (Sweden)

    Misha Koshelev

    2010-10-01

    Full Text Available We used a multi-round, two-party exchange game in which a healthy subject played a subject diagnosed with a DSM-IV (Diagnostic and Statistics Manual-IV disorder, and applied a Bayesian clustering approach to the behavior exhibited by the healthy subject. The goal was to characterize quantitatively the style of play elicited in the healthy subject (the proposer by their DSM-diagnosed partner (the responder. The approach exploits the dynamics of the behavior elicited in the healthy proposer as a biosensor for cognitive features that characterize the psychopathology group at the other side of the interaction. Using a large cohort of subjects (n = 574, we found statistically significant clustering of proposers' behavior overlapping with a range of DSM-IV disorders including autism spectrum disorder, borderline personality disorder, attention deficit hyperactivity disorder, and major depressive disorder. To further validate these results, we developed a computer agent to replace the human subject in the proposer role (the biosensor and show that it can also detect these same four DSM-defined disorders. These results suggest that the highly developed social sensitivities that humans bring to a two-party social exchange can be exploited and automated to detect important psychopathologies, using an interpersonal behavioral probe not directly related to the defining diagnostic criteria.

  5. Simulation of Biosensor using FEM

    International Nuclear Information System (INIS)

    Sheeparamatti, B G; Hebbal, M S; Sheeparamatti, R B; Math, V B; Kadadevaramath, J S

    2006-01-01

    Bio-Micro Electro Mechanical Systems/Nano Electro Mechanical Systems include a wide variety of sensors, actuators, and complex micro/nano devices for biomedical applications. Recent advances in biosensors have shown that sensors based on bending of microfabricated cantilevers have potential advantages over earlier used detection methods. Thus, a simple cantilever beam can be used as a sensor for biomedical, chemical and environmental applications. Here, microfabricated multilayered cantilever beam is exposed to sensing environment. Lower layer being pure structural silicon or polymer and upper layer is of polymer with antigen/antibody immobilized in it. Obviously, it has an affinity towards its counterpart i.e. antibody/antigen. In the sensing environment, if counter elements exists, they get captured by this sensing beam head, and the cantilever beam deflects. This deflection can be sensed and the presence of counter elements in the environment can be predicted. In this work, a finite element model of a biosensor for sensing antibody/antigen reaction is developed and simulated using ANSYS/Multiphysics. The optimal dimensions of the microcantilever beam are selected based on permissible deflection range with the aid of MATLAB. In the model analysis, both weight and surface stress effects on the cantilever are considered. Approximate weights are taken into account because of counter elements, considering their molecular weight and possible number of elements required for sensing. The results obtained in terms of lateral deflection are presented

  6. Electroacoustic miniaturized DNA-biosensor.

    Science.gov (United States)

    Gamby, Jean; Lazerges, Mathieu; Pernelle, Christine; Perrot, Hubert; Girault, Hubert H; Tribollet, Bernard

    2007-11-01

    A micrometer-sized electroacoustic DNA-biosensor was developed. The device included a thin semi-crystalline polyethylene terephthalate (PET) dielectric layer with two Ag microband electrodes on one side and a DNA thiol-labeled monolayer adsorbed on a gold surface on the other. A resonance wave was observed at 29 MHz with a network analyzer, upon AC voltage application between the two Ag electrodes, corresponding to electromechanical coupling induced by molecular dipoles of the PET polymer chain in the dielectric layer. It was found that the device size and geometry were well adapted to detect DNA hybridization, by measuring the capacity of the resonance response evolution: hybridization induced polarization of the dielectric material that affected the electromechanical coupling established in the dielectric layer. The 0.2 mm(2) sensor sensitive area allows detection in small volumes and still has higher detection levels for bioanalytical applications, the non-contact configuration adopted avoids electric faradic reactions that may damage biosensor sensitive layers, and finally, PET is a costless raw material, easy to process and well adapted for large scale production. The well-balanced technological and economic advantages of this kind of device make it a good candidate for biochip integration.

  7. Zinc oxide nano-rods based glucose biosensor devices fabrication

    Science.gov (United States)

    Wahab, H. A.; Salama, A. A.; El Saeid, A. A.; Willander, M.; Nur, O.; Battisha, I. K.

    2018-06-01

    ZnO is distinguished multifunctional material that has wide applications in biochemical sensor devices. For extracellular measurements, Zinc oxide nano-rods will be deposited on conducting plastic substrate with annealing temperature 150 °C (ZNRP150) and silver wire with annealing temperature 250 °C (ZNRW250), for the extracellular glucose concentration determination with functionalized ZNR-coated biosensors. It was performed in phosphate buffer saline (PBS) over the range from 1 μM to 10 mM and on human blood plasma. The prepared samples crystal structure and surface morphologies were characterized by XRD and field emission scanning electron microscope FESEM respectively.

  8. Design Strategies for Aptamer-Based Biosensors

    Science.gov (United States)

    Han, Kun; Liang, Zhiqiang; Zhou, Nandi

    2010-01-01

    Aptamers have been widely used as recognition elements for biosensor construction, especially in the detection of proteins or small molecule targets, and regarded as promising alternatives for antibodies in bioassay areas. In this review, we present an overview of reported design strategies for the fabrication of biosensors and classify them into four basic modes: target-induced structure switching mode, sandwich or sandwich-like mode, target-induced dissociation/displacement mode and competitive replacement mode. In view of the unprecedented advantages brought about by aptamers and smart design strategies, aptamer-based biosensors are expected to be one of the most promising devices in bioassay related applications. PMID:22399891

  9. Improved biosensor-based detection system

    DEFF Research Database (Denmark)

    2015-01-01

    Described is a new biosensor-based detection system for effector compounds, useful for in vivo applications in e.g. screening and selecting of cells which produce a small molecule effector compound or which take up a small molecule effector compound from its environment. The detection system...... comprises a protein or RNA-based biosensor for the effector compound which indirectly regulates the expression of a reporter gene via two hybrid proteins, providing for fewer false signals or less 'noise', tuning of sensitivity or other advantages over conventional systems where the biosensor directly...

  10. Development of Single-Walled Carbon Nanotube-Based Biosensor for the Detection of Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Hyun-Kyung Choi

    2017-01-01

    Full Text Available The goal of this research is to develop a single-walled carbon nanotube- (SWCNT- based biosensor to detect Staphylococcus aureus. The specificity of 11 bacteria and polyclonal anti-Staphylococcus aureus antibodies (pAbs was determined using an indirect ELISA. The pAbs were immobilized onto sensor platform after the hybridization of 1-pyrenebutanoic acid succinimidyl ester (PBASE. The resistance difference (ΔR was calculated using a potentiostat. The bacteria detected by the biosensor were observed using a scanning electron microscope (SEM. The optimum concentration of SWCNTs on the platform was determined to be 0.1 mg/mL. The binding of pAbs with S. aureus resulted in a significant increase in resistance value of the biosensor (P<0.05. The SEM images confirmed the specific binding of S. aureus on the biosensor. The SWCNT-based biosensor was able to detect S. aureus with a limit of detection (LOD of 4 log⁡CFU/mL.

  11. Glucose biosensor based on glucose oxidase immobilized on unhybridized titanium dioxide nanotube arrays

    International Nuclear Information System (INIS)

    Wang, Wei; Xie, Yibing; Du, Hongxiu; Xia, Chi; Wang, Yong; Tian, Fang

    2014-01-01

    A glucose biosensor has been fabricated by immobilizing glucose oxidase (GOx) on unhybridized titanium dioxide nanotube arrays using an optimized cross-linking technique. The TiO 2 nanotube arrays were synthesized directly on a titanium substrate by anodic oxidation. The structure and morphology of electrode material were characterized by X-ray diffraction and scanning electron microscopy. The electrochemical performances of the glucose biosensor were conducted by cyclic voltammetry and chronoamperometry measurements. It gives a linear response to glucose in the 0.05 to 0.65 mM concentration range, with a correlation coefficient of 0.9981, a sensitivity of 199.6 μA mM −1 cm −2 , and a detection limit as low as 3.8 µM. This glucose biosensor exhibited high selectivity for glucose determination in the presence of ascorbic acid, sucrose and other common interfering substances. This glucose biosensor also performed good reproducibility and long-time storage stability. This optimized cross-linking technique could open a new avenue for other enzyme biosensors fabrication. (author)

  12. Glucose Sensing Using Capacitive Biosensor Based on Polyvinylidene Fluoride Thin Film

    Directory of Open Access Journals (Sweden)

    Ambran Hartono

    2018-01-01

    Full Text Available A polyvinylidene fluoride (PVDF film-based capacitive biosensor was developed for glucose sensing. This device consists of a PVDF film sandwiched between two electrodes. A capacitive biosensor measures the dielectric properties of the dielectric layers at the interface between the electrolyte and the electrode. A glucose oxidase (GOx enzyme was immobilized onto the electrode to oxidize glucose. In practice, the biochemical reaction of glucose with the GOx enzyme generates free electron carriers. Consequently, the potential difference between the electrodes is increased, resulting in a measurable voltage output of the biosensor. The device was tested for various glucose concentrations in the range of 0.013 to 5.85 M, and various GOx enzyme concentrations between 4882.8 and 2.5 million units/L. We found that the sensor output increased with increasing glucose concentration up to 5.85 M. These results indicate that the PVDF film-based capacitive biosensors can be properly applied to glucose sensing and provide opportunities for the low-cost fabrication of glucose-based biosensors based on PVDF materials.

  13. Potentiometric urea biosensor utilizing nanobiocomposite of chitosan-iron oxide magnetic nanoparticles

    International Nuclear Information System (INIS)

    Ali, A; Israr, M Q; Sadaf, J R; Nur, O; Willander, M; AlSalhi, M S; Atif, M; Ansari, Anees A; Ahmed, E

    2013-01-01

    The iron oxide (Fe 3 O 4 ) magnetic nanoparticles have been fabricated through a simple, cheap and reproducible approach. Scanning electron microscope, x-rays powder diffraction of the fabricated nanoparticles. Furthermore, the fabrication of potentiometric urea biosensor is carried out through drop casting the initially prepared isopropanol and chitosan solution, containing Fe 3 O 4 nanoparticles, on the glass fiber filter with a diameter of 2 cm and a copper wire (of thickness −500 μm) has been utilized to extract the voltage signal from the functionalized nanoparticles. The functionalization of surface of the Fe 3 O 4 nanoparticles is obtained by the electrostatically immobilization of urease onto the nanobiocomposite of the chitosan- Fe 3 O 4 in order to enhance the sensitivity, specificity, stability and reusability of urea biosensor. Electrochemical detection procedure has been adopted to measure the potentiometric response over the wide logarithmic concentration range of the 0.1 mM to 80 mM. The Fe 3 O 4 nanoparticles based urea biosensor depicts good sensitivity with ∼42 mV per decade at room temperature. Durability of the biosensor could be considerably enhanced by applying a thin layer of the nafion. In addition, the reasonably stable output response of the biosensor has been found to be around 12 sec.

  14. Ordered mesoporous polyaniline film as a new matrix for enzyme immobilization and biosensor construction

    International Nuclear Information System (INIS)

    Xu Qin; Zhu Junjie; Hu Xiaoya

    2007-01-01

    Ordered mesoporous polyaniline film has been fabricated by electrodepositing from the hexagonal lyotropic liquid crystalline (LCC). Horseradish peroxidase (HRP), as a symbol biomolecule, was successfully immobilized on the film to construct a new kind of hydrogen peroxide biosensor. The biosensor combined the advantages of the good conductivity of polyaniline and the higher surface area of the ordered mesoporous film. Polyaniline could be served as a wire to relay electron between HRP and the electrode. The high surface area of the film supplied more sites for HRP immobilization, therefore increased the catalytic activity of the biosensor. The ordered mesoporous character of the film increased the rate of mass transport, which resulted in the improvement of sensor response and linearity. The biosensor displayed excellent electrocatalytic response to the detection of H 2 O 2 in a concentration range from 1.0 μM to 2.0 mM with a detection limit of 0.63 μM. Good reproducibility, stability, high precision, wide linearity and low detection limit were assessed for the biosensor

  15. A novel tyrosinase biosensor based on hydroxyapatite-chitosan nanocomposite for the detection of phenolic compounds

    International Nuclear Information System (INIS)

    Lu Limin; Zhang Li; Zhang Xiaobing; Huan Shuangyan; Shen Guoli; Yu Ruqin

    2010-01-01

    A novel tyrosinase biosensor based on hydroxyapatite nanoparticles (nano-HA)-chitosan nanocomposite has been developed for the detection of phenolic compounds. The uniform and size controlled nano-HA was synthesized by hydrothermal method, and its morphological characterization was examined by transmission electron microscope (TEM). Tyrosinase was then immobilized on a nano-HA-chitosan nanocomposite-modified gold electrode. Electrochemical impedance spectroscopy and cyclic voltammetry were used to characterize the sensing film. The prepared biosensor was applied to determine phenolic compounds by monitoring the reduction signal of the biocatalytically produced quinone species at -0.2 V (vs. saturated calomel electrode). The effects of the pH, temperature and applied potential on the biosensor performance were investigated, and experimental conditions were optimized. The biosensor exhibited a linear response to catechol over a wide concentration range from 10 nM to 7 μM, with a high sensitivity of 2.11 x 10 3 μA mM -1 cm -2 , and a limit of detection down to 5 nM (based on S/N = 3). The apparent Michaelis-Menten constants of the enzyme electrode were estimated to be 3.16, 1.31 and 3.52 μM for catechol, phenol and m-cresol, respectively. Moreover, the stability and reproducibility of this biosensor were evaluated with satisfactory results.

  16. Novel electrochemical xanthine biosensor based on chitosan–polypyrrole–gold nanoparticles hybrid bio-nanocomposite platform

    Directory of Open Access Journals (Sweden)

    Muamer Dervisevic

    2017-07-01

    Full Text Available The aim of this study was the electrochemical detection of the adenosine-3-phosphate degradation product, xanthine, using a new xanthine biosensor based on a hybrid bio-nanocomposite platform which has been successfully employed in the evaluation of meat freshness. In the design of the amperometric xanthine biosensor, chitosan–polypyrrole–gold nanoparticles fabricated by an in situ chemical synthesis method on a glassy carbon electrode surface was used to enhance electron transfer and to provide good enzyme affinity. Electrochemical studies were carried out by the modified electrode with immobilized xanthine oxidase on it, after which the biosensor was tested to ascertain the optimization parameters. The Biosensor exhibited a very good linear range of 1–200 μM, low detection limit of 0.25 μM, average response time of 8 seconds, and was not prone to significant interference from uric acid, ascorbic acid, glucose, and sodium benzoate. The resulting bio-nanocomposite xanthine biosensor was tested with fish, beef, and chicken real-sample measurements.

  17. Detection of parathyroid hormone using an electrochemical impedance biosensor based on PAMAM dendrimers.

    Science.gov (United States)

    Özcan, Hakkı Mevlüt; Sezgintürk, Mustafa Kemal

    2015-01-01

    This paper presents a novel hormone-based impedimetric biosensor to determine parathyroid hormone (PTH) level in serum for diagnosis and monitoring treatment of hyperparathyroidism, hypoparathyroidism and thyroid cancer. The interaction between PTH and the biosensor was investigated by an electrochemical method. The biosensor was based on the gold electrode modified by 12-mercapto dodecanoic (12MDDA). Antiparathyroid hormone (anti-PTH) was covalently immobilized on to poly amidoamine dendrimer (PAMAM) which was bound to a 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide/N-hydroxysuccinimide (EDC/NHS) couple, self-assembled monolayer structure from one of the other NH2 sites. The immobilization of anti-PTH was monitored by electrochemical impedance spectroscopy, cyclic voltammetry and scanning electron microscope techniques. After the optimization studies of immobilization materials such as 12MDDA, EDC-NHS, PAMAM, and glutaraldehyde, the performance of the biosensor was investigated in terms of linearity, sensitivity, repeatability, and reproducibility. PTH was detected within a linear range of 10-60 fg/mL. Finally the described biosensor was used to monitor PTH levels in artificial serum samples. © 2015 American Institute of Chemical Engineers.

  18. Development of electrochemical biosensor for detection of pathogenic microorganism in Asian dust events.

    Science.gov (United States)

    Yoo, Min-Sang; Shin, Minguk; Kim, Younghun; Jang, Min; Choi, Yoon-E; Park, Si Jae; Choi, Jonghoon; Lee, Jinyoung; Park, Chulhwan

    2017-05-01

    We developed a single-walled carbon nanotubes (SWCNTs)-based electrochemical biosensor for the detection of Bacillus subtilis, one of the microorganisms observed in Asian dust events, which causes respiratory diseases such as asthma and pneumonia. SWCNTs plays the role of a transducer in biological antigen/antibody reaction for the electrical signal while 1-pyrenebutanoic acid succinimidyl ester (1-PBSE) and ant-B. subtilis were performed as a chemical linker and an acceptor, respectively, for the adhesion of target microorganism in the developed biosensor. The detection range (10 2 -10 10  CFU/mL) and the detection limit (10 2  CFU/mL) of the developed biosensor were identified while the response time was 10 min. The amount of target B. subtilis was the highest in the specificity test of the developed biosensor, compared with the other tested microorganisms (Staphylococcus aureus, Flavobacterium psychrolimnae, and Aquabacterium commune). In addition, target B. subtilis detected by the developed biosensor was observed by scanning electron microscope (SEM) analysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Nanomolar detection of methylparaben by a cost-effective hemoglobin-based biosensor.

    Science.gov (United States)

    Hajian, A; Ghodsi, J; Afraz, A; Yurchenko, O; Urban, G

    2016-12-01

    This work describes the development of a new biosensor for methylparaben determination using electrocatalytic properties of hemoglobin in the presence of hydrogen peroxide. The voltammetric oxidation of methylparaben by the proposed biosensor in phosphate buffer (pH=7.0), a physiological pH, was studied and it was confirmed that methylparaben undergoes a one electron-one proton reaction in a diffusion-controlled process. The biosensor was fabricated by carbon paste electrode modified with hemoglobin and multiwalled carbon nanotube. Based on the excellent electrochemical properties of the modified electrode, a sensitive voltammetric method was used for determination of methylparaben within a linear range from 0.1 to 13μmolL(-1) and detection limit of 25nmolL(-1). The developed biosensor possessed accurate and rapid response to methylparaben and showed good sensitivity, stability, and repeatability. Finally, the applicability of the proposed biosensor was verified by methylparaben evaluation in various real samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Mechanistic modeling of cyclic voltammetry: A helpful tool for understanding biosensor principles and supporting design optimization

    DEFF Research Database (Denmark)

    Semenova, Daria; Zubov, Alexandr; Silina, Yuliya E.

    2018-01-01

    Abstract Design, optimization and integration of biosensors hold a great potential for the development of cost-effective screening and point-of-care technologies. However, significant progress in this field can still be obtained on condition that sufficiently accurate mathematical models......, oxidized/reduced forms of the mediator - Prussian Blue/Prussian White). Furthermore, the developed model was applied under various operating conditions as a crucial tool for biosensor design optimization. The obtained qualitative and quantitative dependencies towards amperometric biosensors design...... optimization were independently supported by results of cyclic voltammetry and multi-analytical studies, such as scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). Remarkably, a linear...

  1. Utilization of Diamine Oxidase Enzyme from Mung Bean Sprouts (Vigna radiata L) for Histamine biosensors

    Science.gov (United States)

    Karim, Abdul; Wahab, A. W.; Raya, I.; Natsir, H.; Arif, A. R.

    2018-03-01

    This research is aimed to utilize the diamine oxidase enzyme (DAO) which isolated from mung bean sprouts (Vigna radiata L) to develop histamine biosensors based on electode enzyme with the amperometric method (cyclic voltammetry).The DAO enzyme is trapped inside the membrane of chitin-cellulose acetate 2:1 and glutaraldehyde which super imposed on a Pt electrode. Histamine will be oxidized by DAO enzyme to produce aldehydes and H2O2 that acting as electron transfer mediators.The performance of biosensors will be measured at various concentrations of glutaraldehyde, temperature changes and different range of pH. Recently, it has been found that the optimal conditions obtained from the paramaters as follows; at 25% of glutaraldehyde, temperature of 37°C and pH of 7.4. Eventually, the results provided an expectation for applying histamine biosensors in determining the freshness and safety of fish specifically skombroidae families.

  2. 3D hydrogel scaffold doped with 2D graphene materials for biosensors and bioelectronics.

    Science.gov (United States)

    Song, Hyun Seok; Kwon, Oh Seok; Kim, Jae-Hong; Conde, João; Artzi, Natalie

    2017-03-15

    Hydrogels consisting of three-dimensional (3D) polymeric networks have found a wide range of applications in biotechnology due to their large water capacity, high biocompatibility, and facile functional versatility. The hydrogels with stimulus-responsive swelling properties have been particularly instrumental to realizing signal transduction in biosensors and bioelectronics. Graphenes are two-dimensional (2D) nanomaterials with unprecedented physical, optical, and electronic properties and have also found many applications in biosensors and bioelectronics. These two classes of materials present complementary strengths and limitations which, when effectively coupled, can result in significant synergism in their electrical, mechanical, and biocompatible properties. This report reviews recent advances made with hydrogel and graphene materials for the development of high-performance bioelectronics devices. The report focuses on the interesting intersection of these materials wherein 2D graphenes are hybridized with 3D hydrogels to develop the next generation biosensors and bioelectronics. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. DNA biosensor by self-assembly of carbon nanotubes and DNA to detect riboflavin

    Energy Technology Data Exchange (ETDEWEB)

    Li Jing [College of Chemistry and Chemical Engineering. Chongqing University, ChongQing, 400044 (China); Zhang Yunhuai, E-mail: xp2031@163.com [College of Chemistry and Chemical Engineering. Chongqing University, ChongQing, 400044 (China); Yang Tongyi [School of Life Science. NanJing University, Nanjing, 210093 (China); Zhang Huai [Liming Research Institute of Chemical Industry, LuoYang, 471001 (China); Yang Yixuan [State Key Laboratory of Chemical Resource Engineering. Beijing University of Chemical Technology, Beijing 100029 (China); Xiao Peng [College of Mathematics and Physics, Chongqing University, Chongqing 400044 (China)

    2009-10-15

    The fabrication of biosensors via self-assembly of single-walled carbon nanotubes (SWNTs) and DNA on a platinum electrode was presented in this paper. The carboxylic SWNTs were assembled on an amine-modified platinum electrode surface and followed by the assembly of NH{sub 2}-DNA with the carboxyl-amine coupling. The decorated surface was characterized by Field Emission Electron Microscopy (FEG-SEM) and electrochemical experiments, which showed that the reaction of DNA-SWNTs biosensor was quasi-reversible. The mechanism of DNA and riboflavin (VB{sub 2}) was studied by cyclic voltammetry and UV-Vis spectroscopy. The fabricated SWNTs-reinforced biosensor exhibits high sensitivity and low detection limit for the tested VB{sub 2} compared to the reported methods.

  4. The detection of Salmonella typhimurium on shell eggs using a phage-based biosensor

    Science.gov (United States)

    Chai, Yating; Li, Suiqiong; Horikawa, Shin; Shen, Wen; Park, Mi-Kyung; Vodyanoy, Vitaly J.; Chin, Bryan A.

    2011-06-01

    This paper presents the direct detection of Salmonella typhimurium on shell eggs using a phage-based magnetoelastic (ME) biosensor. The ME biosensor consists of a ME resonator as the sensor platform and E2 phage as the biorecognition element that is genetically engineered to specifically bind with Salmonella typhimurium. The ME biosensor, which is a wireless sensor, vibrates with a characteristic resonant frequency under an externally applied magnetic field. Multiple sensors can easily be remotely monitored. Multiple measurement and control sensors were placed on the shell eggs contaminated by Salmonella typhimurium solutions with different known concentrations. The resonant frequency of sensors before and after the exposure to the spiked shell eggs was measured. The frequency shift of the measurement sensors was significantly different than the control sensors indicating Salmonella contamination. Scanning electron microscopy was used to confirm binding of Salmonella to the sensor surface and the resulting frequency shift results.

  5. Electrochemical Biosensors - Sensor Principles and Architectures

    Science.gov (United States)

    Grieshaber, Dorothee; MacKenzie, Robert; Vörös, Janos; Reimhult, Erik

    2008-01-01

    Quantification of biological or biochemical processes are of utmost importance for medical, biological and biotechnological applications. However, converting the biological information to an easily processed electronic signal is challenging due to the complexity of connecting an electronic device directly to a biological environment. Electrochemical biosensors provide an attractive means to analyze the content of a biological sample due to the direct conversion of a biological event to an electronic signal. Over the past decades several sensing concepts and related devices have been developed. In this review, the most common traditional techniques, such as cyclic voltammetry, chronoamperometry, chronopotentiometry, impedance spectroscopy, and various field-effect transistor based methods are presented along with selected promising novel approaches, such as nanowire or magnetic nanoparticle-based biosensing. Additional measurement techniques, which have been shown useful in combination with electrochemical detection, are also summarized, such as the electrochemical versions of surface plasmon resonance, optical waveguide lightmode spectroscopy, ellipsometry, quartz crystal microbalance, and scanning probe microscopy. The signal transduction and the general performance of electrochemical sensors are often determined by the surface architectures that connect the sensing element to the biological sample at the nanometer scale. The most common surface modification techniques, the various electrochemical transduction mechanisms, and the choice of the recognition receptor molecules all influence the ultimate sensitivity of the sensor. New nanotechnology-based approaches, such as the use of engineered ion-channels in lipid bilayers, the encapsulation of enzymes into vesicles, polymersomes, or polyelectrolyte capsules provide additional possibilities for signal amplification. In particular, this review highlights the importance of the precise control over the delicate

  6. Electronic medical records in diabetes consultations: participants' gaze as an interactional resource.

    Science.gov (United States)

    Rhodes, Penny; Small, Neil; Rowley, Emma; Langdon, Mark; Ariss, Steven; Wright, John

    2008-09-01

    Two routine consultations in primary care diabetes clinics are compared using extracts from video recordings of interactions between nurses and patients. The consultations were chosen to present different styles of interaction, in which the nurse's gaze was either primarily toward the computer screen or directed more toward the patient. Using conversation analysis, the ways in which nurses shift both gaze and body orientation between the computer screen and patient to influence the style, pace, content, and structure of the consultation were investigated. By examining the effects of different levels of engagement between the electronic medical record and the embodied patient in the consultation room, we argue for the need to consider the contingent nature of the interface of technology and the person in the consultation. Policy initiatives designed to deliver what is considered best-evidenced practice are modified in the micro context of the interactions of the consultation.

  7. Granulometric composition study of mineral resources using opto-electronic devices and Elsieve software system

    Directory of Open Access Journals (Sweden)

    Kaminski Stanislaw

    2016-01-01

    Full Text Available The use of mechanical sieves has a great impact on measurement results because occurrence of anisometric particles causes undercounting the average size. Such errors can be avoided by using opto-electronic measuring devices that enable measurement of particles from 10 μm up to a few dozen millimetres in size. The results of measurement of each particle size fraction are summed up proportionally to its weight with the use of Elsieve software system and for every type of material particle-size distribution can be obtained. The software allows further statistical interpretation of the results. Beam of infrared radiation identifies size of particles and counts them precisely. Every particle is represented by an electronic impulse proportional to its size. Measurement of particles in aqueous suspension that replaces the hydrometer method can be carried out by using the IPS L analyser (range from 0.2 to 600 μm. The IPS UA analyser (range from 0.5 to 2000 μm is designed for measurement in the air. An ultrasonic adapter enables performing measurements of moist and aggregated particles from 0.5 to 1000 μm. The construction and software system allow to determine second dimension of the particle, its shape coefficient and specific surface area. The AWK 3D analyser (range from 0.2 to 31.5 mm is devoted to measurement of various powdery materials with subsequent determination of particle shape. The AWK B analyser (range from 1 to 130 mm measures materials of thick granulation and shape of the grains. The presented method of measurement repeatedly accelerates and facilitates study of granulometric composition.

  8. GMR biosensor arrays: a system perspective.

    Science.gov (United States)

    Hall, D A; Gaster, R S; Lin, T; Osterfeld, S J; Han, S; Murmann, B; Wang, S X

    2010-05-15

    Giant magnetoresistive biosensors are becoming more prevalent for sensitive, quantifiable biomolecular detection. However, in order for magnetic biosensing to become competitive with current optical protein microarray technology, there is a need to increase the number of sensors while maintaining the high sensitivity and fast readout time characteristic of smaller arrays (1-8 sensors). In this paper, we present a circuit architecture scalable for larger sensor arrays (64 individually addressable sensors) while maintaining a high readout rate (scanning the entire array in less than 4s). The system utilizes both time domain multiplexing and frequency domain multiplexing in order to achieve this scan rate. For the implementation, we propose a new circuit architecture that does not use a classical Wheatstone bridge to measure the small change in resistance of the sensor. Instead, an architecture designed around a transimpedance amplifier is employed. A detailed analysis of this architecture including the noise, distortion, and potential sources of errors is presented, followed by a global optimization strategy for the entire system comprising the magnetic tags, sensors, and interface electronics. To demonstrate the sensitivity, quantifiable detection of two blindly spiked samples of unknown concentrations has been performed at concentrations below the limit of detection for the enzyme-linked immunosorbent assay. Lastly, the multiplexing capability and reproducibility of the system was demonstrated by simultaneously monitoring sensors functionalized with three unique proteins at different concentrations in real-time. 2010 Elsevier B.V. All rights reserved.

  9. Sensitive amperometric biosensor for phenolic compounds based on graphene-silk peptide/tyrosinase composite nanointerface.

    Science.gov (United States)

    Qu, Ying; Ma, Ming; Wang, Zhengguo; Zhan, Guoqing; Li, Buhai; Wang, Xian; Fang, Huaifang; Zhang, Huijuan; Li, Chunya

    2013-06-15

    New graphene-silk peptide (Gr-SP) nanosheets were prepared and successfully fabricated with tyrosinase (Tyr) as a novel biosensor for the determination of phenolic compounds. The Gr-SP nanosheets were fully characterized with transmission electron microscopy, x-ray diffraction, x-ray photoelectron spectroscopy, UV/Vis and FTIR spectra. The developed biosensors were also characterized with scanning electronic microscopy and electrochemical impedance spectroscopy. Using bisphenol A (BPA) as a model substrate in the sensing system, a number of key factors including the volume of Gr-SP-Tyr solution, the applied potential, pH values, temperature, and the Tyr/Gr-SP ratio that influence the analytical performance of the biosensor were investigated. The biosensor gave a linear response on the concentration ranges of 0.001-16.91 μM for catechol with the sensitivity of 7634 mA M(-1)cm(-2), 0.0015-21.12 μM for phenol with the sensitivity of 4082 mA M(-1)cm(-2), and 0.002-5.48 μM for BPA with the sensitivity of 2511 mA M(-1)cm(-2). The low detection limits were estimated to be 0.23, 0.35 and 0.72 nM (S/N=3) for catechol, phenol and BPA, respectively. The biosensors also exhibit good repeatability and long-term stability. The practical application of the biosensor was also demonstrated by the determination of BPA leaching from commercial plastic drinking bottles. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Glucose biosensor based on glucose oxidase immobilized at gold nanoparticles decorated graphene-carbon nanotubes.

    Science.gov (United States)

    Devasenathipathy, Rajkumar; Mani, Veerappan; Chen, Shen-Ming; Huang, Sheng-Tung; Huang, Tsung-Tao; Lin, Chun-Mao; Hwa, Kuo-Yuan; Chen, Ting-Yo; Chen, Bo-Jun

    2015-10-01

    Biopolymer pectin stabilized gold nanoparticles were prepared at graphene and multiwalled carbon nanotubes (GR-MWNTs/AuNPs) and employed for the determination of glucose. The formation of GR-MWNTs/AuNPs was confirmed by scanning electron microscopy, X-ray diffraction, UV-vis and FTIR spectroscopy methods. Glucose oxidase (GOx) was successfully immobilized on GR-MWNTs/AuNPs film and direct electron transfer of GOx was investigated. GOx exhibits highly enhanced redox peaks with formal potential of -0.40 V (vs. Ag/AgCl). The amount of electroactive GOx and electron transfer rate constant were found to be 10.5 × 10(-10) mol cm(-2) and 3.36 s(-1), respectively, which were significantly larger than the previous reports. The fabricated amperometric glucose biosensor sensitively detects glucose and showed two linear ranges: (1) 10 μM - 2 mM with LOD of 4.1 μM, (2) 2 mM - 5.2 mM with LOD of 0.95 mM. The comparison of the biosensor performance with reported sensors reveals the significant improvement in overall sensor performance. Moreover, the biosensor exhibited appreciable stability, repeatability, reproducibility and practicality. The other advantages of the fabricated biosensor are simple and green fabrication approach, roughed and stable electrode surface, fast in sensing and highly reproducible. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. An Epidermal Biosensor for Carcinoembryonic Antigen

    National Research Council Canada - National Science Library

    Schwartz, Pauline

    2001-01-01

    ...). An epidermal biosensor is a new approach for the early continuous, in vivo detection of the onset of disease by the using genetically modified skin cells to respond to molecules secreted by tumor cells...

  12. An Epidermal Biosensor for Carcinoembryonic Antigen

    National Research Council Canada - National Science Library

    Schwartz, Pauline

    2003-01-01

    ...) An epidermal biosensor was conceived as a new approach for the early continuous, in vivo detection of the onset of disease by the using genetically modified skin cells to respond to molecules secreted by tumor cells...

  13. Polymer Based Biosensors for Medical Applications

    DEFF Research Database (Denmark)

    Cherré, Solène; Rozlosnik, Noemi

    2015-01-01

    , environmental monitoring and food safety. The detected element varies from a single molecule (such as glucose), a biopolymer (such as DNA or a protein) to a whole organism (such as bacteria). Due to their easy use and possible miniaturization, biosensors have a high potential to come out of the lab...... and be available for use by everybody. To fulfil these purposes, polymers represent very appropriate materials. Many nano- and microfabrication methods for polymers are available, allowing a fast and cheap production of devices. This chapter will present the general concept of a biosensor in a first part......The objective of this chapter is to give an overview about the newest developments in biosensors made of polymers for medical applications. Biosensors are devices that can recognize and detect a target with high selectivity. They are widely used in many fields such as medical diagnostic...

  14. Biosensors in immunology: the story so far

    NARCIS (Netherlands)

    Pathak, S.S.; Savelkoul, H.F.J.

    1997-01-01

    Optical biosensors are finding a range of applications in immunology. They enable biomolecular interactions to be characterized in real time without the need to label reactants, and, because individual binding steps can be visualized, are particularly suited to complex assays

  15. Biosensors for cardiac biomarkers detection: a review

    OpenAIRE

    Qureshi, Anjum; Gürbüz, Yaşar; Gurbuz, Yasar; Kolkar Mohammed, Javed Hussain Niazi

    2012-01-01

    The cardiovascular disease (CVD) is considered as a major threat to global health. Therefore, there is a growing demand for a range of portable, rapid and low cost biosensing devices for the detection of CVD. Biosensors can play an important role in the early diagnosis of CVD without having to rely on hospital visits where expensive and time-consuming laboratory tests are recommended. Over the last decade, many biosensors have been developed to detect a wide range of cardiac marker to reduce ...

  16. Synthetic biology for microbial heavy metal biosensors.

    Science.gov (United States)

    Kim, Hyun Ju; Jeong, Haeyoung; Lee, Sang Jun

    2018-02-01

    Using recombinant DNA technology, various whole-cell biosensors have been developed for detection of environmental pollutants, including heavy metal ions. Whole-cell biosensors have several advantages: easy and inexpensive cultivation, multiple assays, and no requirement of any special techniques for analysis. In the era of synthetic biology, cutting-edge DNA sequencing and gene synthesis technologies have accelerated the development of cell-based biosensors. Here, we summarize current technological advances in whole-cell heavy metal biosensors, including the synthetic biological components (bioparts), sensing and reporter modules, genetic circuits, and chassis cells. We discuss several opportunities for improvement of synthetic cell-based biosensors. First, new functional modules must be discovered in genome databases, and this knowledge must be used to upgrade specific bioparts through molecular engineering. Second, modules must be assembled into functional biosystems in chassis cells. Third, heterogeneity of individual cells in the microbial population must be eliminated. In the perspectives, the development of whole-cell biosensors is also discussed in the aspects of cultivation methods and synthetic cells.

  17. Yeast-based biosensors: design and applications.

    Science.gov (United States)

    Adeniran, Adebola; Sherer, Michael; Tyo, Keith E J

    2015-02-01

    Yeast-based biosensing (YBB) is an exciting research area, as many studies have demonstrated the use of yeasts to accurately detect specific molecules. Biosensors incorporating various yeasts have been reported to detect an incredibly large range of molecules including but not limited to odorants, metals, intracellular metabolites, carcinogens, lactate, alcohols, and sugars. We review the detection strategies available for different types of analytes, as well as the wide range of output methods that have been incorporated with yeast biosensors. We group biosensors into two categories: those that are dependent upon transcription of a gene to report the detection of a desired molecule and those that are independent of this reporting mechanism. Transcription-dependent biosensors frequently depend on heterologous expression of sensing elements from non-yeast organisms, a strategy that has greatly expanded the range of molecules available for detection by YBBs. Transcription-independent biosensors circumvent the problem of sensing difficult-to-detect analytes by instead relying on yeast metabolism to generate easily detected molecules when the analyte is present. The use of yeast as the sensing element in biosensors has proven to be successful and continues to hold great promise for a variety of applications. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.

  18. Biosensors-on-chip: a topical review

    International Nuclear Information System (INIS)

    Chen, Sensen; Shamsi, Mohtashim H

    2017-01-01

    This review will examine the integration of two fields that are currently at the forefront of science, i.e. biosensors and microfluidics. As a lab-on-a-chip (LOC) technology, microfluidics has been enriched by the integration of various detection tools for analyte detection and quantitation. The application of such microfluidic platforms is greatly increased in the area of biosensors geared towards point-of-care diagnostics. Together, the merger of microfluidics and biosensors has generated miniaturized devices for sample processing and sensitive detection with quantitation. We believe that microfluidic biosensors (biosensors-on-chip) are essential for developing robust and cost effective point-of-care diagnostics. This review is relevant to a variety of disciplines, such as medical science, clinical diagnostics, LOC technologies including MEMs/NEMs, and analytical science. Specifically, this review will appeal to scientists working in the two overlapping fields of biosensors and microfluidics, and will also help new scientists to find their directions in developing point-of-care devices. (topical review)

  19. The effect of pH and DNA concentration on organic thin-film transistor biosensors

    KAUST Repository

    Khan, Hadayat Ullah

    2012-03-01

    Organic electronics are beginning to attract more interest for biosensor technology as they provide an amenable interface between biology and electronics. Stable biosensor based on electronic detection platform would represent a significant advancement in technology as costs and analysis time would decrease immensely. Organic materials provide a route toward that goal due to their compatibility with electronic applications and biological molecules. In this report, we detail the effects of experimental parameters, such as pH and concentration, toward the selective detection of DNA via surface-bound peptide nucleic acid (PNA) sequences on organic transistor biosensors. The OTFT biosensors are fabricated with thin-films of the organic semiconductor, 5,5′-bis-(7-dodecyl-9H-fluoren-2-yl)-2,2′-bithiophene (DDFTTF), in which they exhibit a stable mobility of 0.2 cm 2 V -1 s -1 in buffer solutions (phosphate-buffer saline, pH 7.4 or sodium acetate, pH 7). Device performance were optimized to minimize the deleterious effects of pH on gate-bias stress such that the sensitivity toward DNA detection can be improved. In titration experiments, the surface-bound PNA probes were saturated with 50 nM of complementary target DNA, which required a 10-fold increase in concentration of single-base mismatched target DNA to achieve a similar surface saturation. The binding constant of DNA on the surface-bound PNA probes was determined from the concentration-dependent response (titration measurements) of our organic transistor biosensors. © 2011 Elsevier B.V. All rights reserved.

  20. The effect of pH and DNA concentration on organic thin-film transistor biosensors

    KAUST Repository

    Khan, Hadayat Ullah; Roberts, Mark E.; Johnson, Olasupo B.; Knoll, Wolfgang; Bao, Zhenan

    2012-01-01

    Organic electronics are beginning to attract more interest for biosensor technology as they provide an amenable interface between biology and electronics. Stable biosensor based on electronic detection platform would represent a significant advancement in technology as costs and analysis time would decrease immensely. Organic materials provide a route toward that goal due to their compatibility with electronic applications and biological molecules. In this report, we detail the effects of experimental parameters, such as pH and concentration, toward the selective detection of DNA via surface-bound peptide nucleic acid (PNA) sequences on organic transistor biosensors. The OTFT biosensors are fabricated with thin-films of the organic semiconductor, 5,5′-bis-(7-dodecyl-9H-fluoren-2-yl)-2,2′-bithiophene (DDFTTF), in which they exhibit a stable mobility of 0.2 cm 2 V -1 s -1 in buffer solutions (phosphate-buffer saline, pH 7.4 or sodium acetate, pH 7). Device performance were optimized to minimize the deleterious effects of pH on gate-bias stress such that the sensitivity toward DNA detection can be improved. In titration experiments, the surface-bound PNA probes were saturated with 50 nM of complementary target DNA, which required a 10-fold increase in concentration of single-base mismatched target DNA to achieve a similar surface saturation. The binding constant of DNA on the surface-bound PNA probes was determined from the concentration-dependent response (titration measurements) of our organic transistor biosensors. © 2011 Elsevier B.V. All rights reserved.

  1. Biosensor

    DEFF Research Database (Denmark)

    2002-01-01

    The invention relates to a biochemical assay for wide class of hydrophobic Coenzyme A esters wherein the analyte is caused to react with a specifically binding, modified protein, and thereby causing a detectable signal. A one step assay for hydrophobic carboxylic acid esters in whole blood, serum...

  2. Green Supply Chain Collaboration for Fashionable Consumer Electronics Products under Third-Party Power Intervention—A Resource Dependence Perspective

    Directory of Open Access Journals (Sweden)

    Jiuh-Biing Sheu

    2014-05-01

    Full Text Available Under third-party power intervention (TPPI, which increases uncertainty in task environments, complex channel power interplays and restructuring are indispensable among green supply chain members as they move toward sustainable collaborative relationships for increased viability and competitive advantage. From the resource dependence perspective, this work presents a novel conceptual model to investigate the influence of political and social power on channel power restructuring and induced green supply chain collaboration in brander-retailer bidirectional green supply chains of fashionable consumer electronics products (FCEPs. An FCEP refers to the consumer electronics product (e.g., personal computers, mobile phones, computer notebooks, and game consoles with the features of a well-known brand associated, a short product lifecycle, timely and fashionable design fit for market trends, and quick responsiveness to the variations of market demands. The proposed model is tested empirically using questionnaire data obtained from retailers in the FCEP brander-retailer distribution channels. Analytical results reveal that as an extension of political and social power, TPPI positively affects the reciprocal interdependence of dyadic members and reduces power asymmetry, thereby enhancing the collaborative relationship of dyadic members and leading to improved green supply chain performance. Therein, reciprocal interdependence underlying collaborative relationship is the key to reducing the external environmental uncertainties in the TPPI context.

  3. Layer-by-layer assemblies of chitosan/multi-wall carbon nanotubes and glucose oxidase for amperometric glucose biosensor applications

    International Nuclear Information System (INIS)

    Wu Baoyan; Hou Shihua; Yu Min; Qin Xia; Li, Sha; Chen Qiang

    2009-01-01

    A novel amperometric glucose biosensor based on multilayer films containing chitosan, multi-wall carbon nanotubes (MWCNTs) and glucose oxidase (GOD) was developed. MWCNTs were solubilized in chitosan (Chit-MWCNTs) used to interact with GOD. Poly (allylamine) (PAA) and polyvinylsulfuric acid potassium salt (PVS) were alternately deposited on the cleaned Pt electrode surface ((PVS/PAA) 3 /Pt). The (PVS/PAA) 3 /Pt electrode was alternately immersed in Chit-MWCNTs and GOD to assemble different layers of multilayer films. PBS washing was applied at the end of each assembly deposition for dissociating the weak adsorption. Micrographs of MWCNTs were obtained by scanning electron microscope, and properties of the resulting biosensors were measured by electrochemical measurements. Among the resulting biosensors, the biosensor based on eight layers of multilayer films was best. The resulting biosensor was able to efficiently monitor glucose, with the response time within 8 s, a detection limit of 21 μM estimated at a signal-to-noise ratio of 3, a linear range of 1-10 mM, the sensitivity of 0.45 μA/mM, and well stability. The study can provide a feasible simple approach on developing a new immobilization matrix for biosensors and surface functionalization

  4. A regenerative electrochemical biosensor for mercury(II) by using the insertion approach and dual-hairpin-based amplification

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Jing; Ling, Yu; Gao, Zhong Feng [Key Laboratory of Eco-Environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Lei, Jing Lei [College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044 (China); Luo, Hong Qun, E-mail: luohq@swu.edu.cn [Key Laboratory of Eco-Environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Li, Nian Bing, E-mail: linb@swu.edu.cn [Key Laboratory of Eco-Environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China)

    2015-09-15

    Highlights: • The dual-hairpin structure as a signal amplifier is label-free and handy. • The strategy uses the insertion approach to improve the hybridization efficiency. • This biosensor has a low detection limit (28 pM) for detection of Hg{sup 2+}. • This biosensor can be easily regenerated by using L-cysteine. - Abstract: A simple and effective biosensor for Hg{sup 2+} determination was investigated. The novel biosensor was prepared by the insertion approach that the moiety-labeled DNA inserted into a loosely packed cyclic-dithiothreitol (DTT) monolayer, improving the hybridization efficiency. Electrochemical impedance spectroscopy studies of two biosensors (single-hairpin and dual-hairpin structure DNA modified electrodes) used for Hg{sup 2+} detection indicated that the dual-hairpin modified electrode had a larger electron transfer resistance change (ΔR{sub ct}). Consequently, the dual-hairpin structure was used as a signal amplifier for the preparation of a selective Hg{sup 2+} biosensor. This biosensor exhibited an excellent selectivity toward Hg{sup 2+} over Cd{sup 2+}, Pd{sup 2+}, Co{sup 2+} etc. Also, a linear relation was observed between the ΔR{sub ct} and Hg{sup 2+} concentrations in a range from 0.1 nM to 5 μM with a detection limit of 28 pM under optimum conditions. Moreover, the biosensor can be reused by using L-cysteine and successfully applied for detecting Hg{sup 2+} in real samples.

  5. Use of Fe3O4 Nanoparticles for Enhancement of Biosensor Response to the Herbicide 2,4-Dichlorophenoxyacetic Acid

    Science.gov (United States)

    Loh, Kee-Shyuan; Lee, Yook Heng; Musa, Ahmad; Salmah, Abdul Aziz; Zamri, Ishak

    2008-01-01

    Magnetic nanoparticles of Fe3O4 were synthesized and characterized using transmission electron microscopy and X-ray diffraction. The Fe3O4 nanoparticles were found to have an average diameter of 5.48 ±1.37 nm. An electrochemical biosensor based on immobilized alkaline phosphatase (ALP) and Fe3O4 nanoparticles was studied. The amperometric biosensor was based on the reaction of ALP with the substrate ascorbic acid 2-phosphate (AA2P). The incorporation of the Fe3O4 nanoparticles together with ALP into a sol gel/chitosan biosensor membrane has led to the enhancement of the biosensor response, with an improved linear response range to the substrate AA2P (5-120 μM) and increased sensitivity. Using the inhibition property of the ALP, the biosensor was applied to the determination of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). The use of Fe3O4 nanoparticles gives a two-fold improvement in the sensitivity towards 2,4-D, with a linear response range of 0.5-30 μgL-1. Exposure of the biosensor to other toxicants such as heavy metals demonstrated only slight interference from metals such as Hg2+, Cu2+, Ag2+ and Pb2+. The biosensor was shown to be useful for the determination of the herbicide 2, 4-D because good recovery of 95-100 percent was obtained, even though the analysis was performed in water samples with a complex matrix. Furthermore, the results from the analysis of 2,4-D in water samples using the biosensor correlated well with a HPLC method. PMID:27873839

  6. Use of Fe3O4 Nanoparticles for Enhancement of Biosensor Response to the Herbicide 2,4-Dichlorophenoxyacetic Acid

    Directory of Open Access Journals (Sweden)

    Ishak Zamri

    2008-09-01

    Full Text Available Magnetic nanoparticles of Fe3O4 were synthesized and characterized using transmission electron microscopy and X-ray diffraction. The Fe3O4 nanoparticles were found to have an average diameter of 5.48 ±1.37 nm. An electrochemical biosensor based on immobilized alkaline phosphatase (ALP and Fe3O4 nanoparticles was studied. The amperometric biosensor was based on the reaction of ALP with the substrate ascorbic acid 2-phosphate (AA2P. The incorporation of the Fe3O4 nanoparticles together with ALP into a sol gel/chitosan biosensor membrane has led to the enhancement of the biosensor response, with an improved linear response range to the substrate AA2P (5-120 μM and increased sensitivity. Using the inhibition property of the ALP, the biosensor was applied to the determination of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D. The use of Fe3O4 nanoparticles gives a two-fold improvement in the sensitivity towards 2,4-D, with a linear response range of 0.5-30 μgL-1. Exposure of the biosensor to other toxicants such as heavy metals demonstrated only slight interference from metals such as Hg2+, Cu2+, Ag2+ and Pb2+. The biosensor was shown to be useful for the determination of the herbicide 2, 4-D because good recovery of 95-100 percent was obtained, even though the analysis was performed in water samples with a complex matrix. Furthermore, the results from the analysis of 2,4-D in water samples using the biosensor correlated well with a HPLC method.

  7. The management of online resources and long-term saving of electronic documents by transfer into the digital space

    Directory of Open Access Journals (Sweden)

    Marius Daniel MAREŞ

    2011-12-01

    The electronic archive refers to the electronic storage system, along with the totality of electronic-type stored documents, while using as storage support any environment that can support storing and from which an electronic document can be presented.

  8. An enzymatic glucose biosensor based on a glassy carbon electrode modified with cylinder-shaped titanium dioxide nanorods

    International Nuclear Information System (INIS)

    Yang, Zhanjun; Xu, Youbao; Li, Juan; Jian, Zhiqin; Yu, Suhua; Zhang, Yongcai; Hu, Xiaoya; Dionysiou, Dionysios D.

    2015-01-01

    We describe a highly sensitive electrochemical enzymatic glucose biosensor. A glassy carbon electrode was modified with cylinder-shaped titanium dioxide nanorods (TiO 2 -NRs) for the immobilization of glucose oxidase. The modified nanorods and the enzyme biosensor were characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, electrochemical impedance spectroscopy and cyclic voltammetry. The glucose oxidase on the TiO 2 -NRs displays a high activity and undergoes fast surface-controlled electron transfer. A pair of well-defined quasi-reversible redox peaks was observed at −0.394 and −0.450 V. The TiO 2 -NRs provide a good microenvironment to facilitate the direct electron transfer between enzyme and electrode surface. The biosensor has two linear response ranges, viz. from 2.0 to 52 μM, and 0.052 to 2.3 mM. The lower detection limit is 0.5 μM, and the sensitivity is 68.58 mA M −1 cm −2 . The glucose biosensor is selective, well reproducible, and stable. In our perception, the cylindrically shaped TiO 2 -NRs provide a promising support for the immobilization of proteins and pave the way to the development of high-performance biosensors. (author)

  9. A glucose biosensor based on glucose oxidase immobilized on three-dimensional porous carbon electrodes.

    Science.gov (United States)

    Chen, Jingyi; Zhu, Rong; Huang, Jia; Zhang, Man; Liu, Hongyu; Sun, Min; Wang, Li; Song, Yonghai

    2015-08-21

    A novel glucose biosensor was developed by immobilizing glucose oxidase (GOD) on a three-dimensional (3D) porous kenaf stem-derived carbon (3D-KSC) which was firstly proposed as a novel supporting material to load biomolecules for electrochemical biosensing. Here, an integrated 3D-KSC electrode was prepared by using a whole piece of 3D-KSC to load the GOD molecules for glucose biosensing. The morphologies of integrated 3D-KSC and 3D-KSC/GOD electrodes were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The SEM results revealed a 3D honeycomb macroporous structure of the integrated 3D-KSC electrode. The TEM results showed some microporosities and defects in the 3D-KSC electrode. The electrochemical behaviors and electrocatalytic performance of the integrated 3D-KSC/GOD electrode were evaluated by cyclic voltammetry and electrochemical impedance spectroscopy. The effects of pH and scan rates on the electrochemical response of the biosensor have been studied in detail. The glucose biosensor showed a wide linear range from 0.1 mM to 14.0 mM with a high sensitivity of 1.73 μA mM(-1) and a low detection limit of 50.75 μM. Furthermore, the glucose biosensor exhibited high selectivity, good repeatability and reproducibility, and good stability.

  10. Poly(3,4-ethylenedioxythiophene)-based glucose biosensors

    NARCIS (Netherlands)

    Kros, A.; Hövell, W.F.M. van; Sommerdijk, N.A.J.M.; Nolte, R.J.M.

    2001-01-01

    Amperometric biosensors for the recognition of glucose oxidase (GOx) based on poly(3,4-ethylenedioxythiophene) (PEDOT) were fabricated for the first time. The resulting biosensor has potential applications for long-term glucose measurements.

  11. Nanopore biosensors for detection of proteins and nucleic acids

    NARCIS (Netherlands)

    Maglia, Giovanni; Soskine, Mikhael

    2014-01-01

    Described herein are nanopore biosensors based on a modified cytolysin protein. The nanopore biosensors accommodate macromoiecules including proteins and nucleic acids, and may additionally comprise ligands with selective binding properties.

  12. Optimization of Xenon Biosensors for Detection of Protein Interactions

    International Nuclear Information System (INIS)

    Lowery, Thomas J.; Garcia, Sandra; Chavez, Lana; Ruiz, E.Janette; Wu, Tom; Brotin, Thierry; Dutasta, Jean-Pierre; King, David S.; Schultz, Peter G.; Pines, Alex; Wemmer, David E.

    2005-08-01

    Hyperpolarized 129Xe NMR can detect the presence of specific low-concentration biomolecular analytes by means of the xenon biosensor, which consists of a water-soluble, targeted cryptophane-A cage that encapsulates xenon. In this work we use the prototypical biotinylated xenon biosensor to determine the relationship between the molecular composition of the xenon biosensor and the characteristics of protein-bound resonances. The effects of diastereomer overlap, dipole-dipole coupling, chemical shift anisotropy, xenon exchange, and biosensor conformational exchange on protein-bound biosensor signal were assessed. It was found that optimal protein-bound biosensor signal can be obtained by minimizing the number of biosensor diastereomers and using a flexible linker of appropriate length. Both the linewidth and sensitivity of chemical shift to protein binding of the xenon biosensor were found to be inversely proportional to linker length

  13. Influence of different nanoparticles on electrochemical behavior of glucose biosensor

    Science.gov (United States)

    Nenkova, R. D.; Ivanov, Y. L.; Godjevargova, T. I.

    2017-02-01

    The influence of nanosized particles on the glucose oxidase loading and the performance of amperometric glucose bionsensors were studied. Four enzyme electrodes (Pt/PAN/GOD, Pt/PAN/NZ/GOD, Pt/PAN/NZ/MNP/GOD, Pt/PAN/NZ/MWNT/GOD) were prepared by cross-linking of glucose oxidase (GOD) on nanocomposite material. Nanocomposites were prepared by entrapping nanozeolite (NZ), multiwalled carbon nanotubes (MWNT) and magnetic nanoparticles (MNP) in polyacrylonitrile (PAN) film. Cyclic voltammetric kinetic studies have been carried out with the four biosensors and the surface concentration of the adsorbed electroactive species on the electrodes was estimated. The highest enzyme concentration on the electrode surface corresponded to the electrodes prepared by nanozeolite separate (Pt/PAN/NZ/GOD) and combined with multi-walled carbon nanotubes (Pt/PAN/NZ/MWNT/GOD). The sensitivity of these two biosensors was the highest and that is in accordance with the greater amount of the adsorbed electroactive species on the electrodes (0.373 mol.cm-2). This was indication that a good synergistic effect happened when MWNTs and NZ were combined and these greatly improve the electron transfer ability of the sensor interface. Amperometric measurement of the two glucose oxidase electrodes (Pt/PAN/NZ/GOD and Pt/PAN/NZ/MWNT/GOD) with best results was carried out. The linear concentration interval of the Pt/PAN/NZ/MWNT/GOD biosensor was up to 3 mM, the detection limit - 0.02 mM glucose and the storage stability - 81% of its initial current response after 30 days.

  14. An ultrasensitive electrochemical DNA biosensor based on a copper oxide nanowires/single-walled carbon nanotubes nanocomposite

    International Nuclear Information System (INIS)

    Chen, Mei; Hou, Changjun; Huo, Danqun; Yang, Mei; Fa, Huanbao

    2016-01-01

    Graphical abstract: A novel and sensitive electrochemical biosensor based on hybrid nanocomposite consisting of copper oxide nanowires (CuO NWs) and carboxyl-functionalized single-walled carbon nanotubes (SWCNTs-COOH) was first developed for the detection of the specific-sequence target DNA. This schematic represents the fabrication procedure of our DNA biosensor. - Highlights: • An ultrasensitive DNA electrochemical biosensor was developed. • CuO NWs entangled with the SWCNTs formed a mesh structure with good conductivity. • It is the first time use of CuONWs-SWCNTs hybrid nanocomposite for DNA detection. • The biosensor is simple, selective, stable, and sensitive. • The biosensor has great potential for use in analysis of real samples. - Abstract: Here, we developed a novel and sensitive electrochemical biosensor to detect specific-sequence target DNA. The biosensor was based on a hybrid nanocomposite consisting of copper oxide nanowires (CuO NWs) and carboxyl-functionalized single-walled carbon nanotubes (SWCNTs-COOH). The resulting CuO NWs/SWCNTs layers exhibited a good differential pulse voltammetry (DPV) current response for the target DNA sequences, which we attributed to the properties of CuO NWs and SWCNTs. CuO NWs and SWCNTs hybrid composites with highly conductive and biocompatible nanostructure were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and cyclic voltammetry (CV). Immobilization of the probe DNA on the electrode surface was largely improved due to the unique synergetic effect of CuO NWs and SWCNTs. DPV was applied to monitor the DNA hybridization event, using adriamycin as an electrochemical indicator. Under optimal conditions, the peak currents of adriamycin were linear with the logarithm of target DNA concentrations (ranging from 1.0 × 10"−"1"4 to 1.0 × 10"−"8 M), with a detection limit of 3.5 × 10"−"1"5 M (signal/noise ratio of 3). The biosensor also showed high selectivity to

  15. An ultrasensitive electrochemical DNA biosensor based on a copper oxide nanowires/single-walled carbon nanotubes nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Mei [Key Laboratory of Biorheology Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Hou, Changjun, E-mail: houcj@cqu.edu.cn [Key Laboratory of Biorheology Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); National Key Laboratory of Fundamental Science of Micro/Nano-Device and System Technology, Chongqing University, Chongqing 400044 (China); Huo, Danqun [Key Laboratory of Biorheology Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); National Key Laboratory of Fundamental Science of Micro/Nano-Device and System Technology, Chongqing University, Chongqing 400044 (China); Yang, Mei [Key Laboratory of Biorheology Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Fa, Huanbao [College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044 (China)

    2016-02-28

    Graphical abstract: A novel and sensitive electrochemical biosensor based on hybrid nanocomposite consisting of copper oxide nanowires (CuO NWs) and carboxyl-functionalized single-walled carbon nanotubes (SWCNTs-COOH) was first developed for the detection of the specific-sequence target DNA. This schematic represents the fabrication procedure of our DNA biosensor. - Highlights: • An ultrasensitive DNA electrochemical biosensor was developed. • CuO NWs entangled with the SWCNTs formed a mesh structure with good conductivity. • It is the first time use of CuONWs-SWCNTs hybrid nanocomposite for DNA detection. • The biosensor is simple, selective, stable, and sensitive. • The biosensor has great potential for use in analysis of real samples. - Abstract: Here, we developed a novel and sensitive electrochemical biosensor to detect specific-sequence target DNA. The biosensor was based on a hybrid nanocomposite consisting of copper oxide nanowires (CuO NWs) and carboxyl-functionalized single-walled carbon nanotubes (SWCNTs-COOH). The resulting CuO NWs/SWCNTs layers exhibited a good differential pulse voltammetry (DPV) current response for the target DNA sequences, which we attributed to the properties of CuO NWs and SWCNTs. CuO NWs and SWCNTs hybrid composites with highly conductive and biocompatible nanostructure were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and cyclic voltammetry (CV). Immobilization of the probe DNA on the electrode surface was largely improved due to the unique synergetic effect of CuO NWs and SWCNTs. DPV was applied to monitor the DNA hybridization event, using adriamycin as an electrochemical indicator. Under optimal conditions, the peak currents of adriamycin were linear with the logarithm of target DNA concentrations (ranging from 1.0 × 10{sup −14} to 1.0 × 10{sup −8} M), with a detection limit of 3.5 × 10{sup −15} M (signal/noise ratio of 3). The biosensor also showed high

  16. Graphene-based field-effect transistor biosensors

    Science.gov (United States)

    Chen; , Junhong; Mao, Shun; Lu, Ganhua

    2017-06-14

    The disclosure provides a field-effect transistor (FET)-based biosensor and uses thereof. In particular, to FET-based biosensors using thermally reduced graphene-based sheets as a conducting channel decorated with nanoparticle-biomolecule conjugates. The present disclosure also relates to FET-based biosensors using metal nitride/graphene hybrid sheets. The disclosure provides a method for detecting a target biomolecule in a sample using the FET-based biosensor described herein.

  17. Development of an Electronic Medical Record Based Alert for Risk of HIV Treatment Failure in a Low-Resource Setting

    Science.gov (United States)

    Puttkammer, Nancy; Zeliadt, Steven; Balan, Jean Gabriel; Baseman, Janet; Destiné, Rodney; Domerçant, Jean Wysler; France, Garilus; Hyppolite, Nathaelf; Pelletier, Valérie; Raphael, Nernst Atwood; Sherr, Kenneth; Yuhas, Krista; Barnhart, Scott

    2014-01-01

    Background The adoption of electronic medical record systems in resource-limited settings can help clinicians monitor patients' adherence to HIV antiretroviral therapy (ART) and identify patients at risk of future ART failure, allowing resources to be targeted to those most at risk. Methods Among adult patients enrolled on ART from 2005–2013 at two large, public-sector hospitals in Haiti, ART failure was assessed after 6–12 months on treatment, based on the World Health Organization's immunologic and clinical criteria. We identified models for predicting ART failure based on ART adherence measures and other patient characteristics. We assessed performance of candidate models using area under the receiver operating curve, and validated results using a randomly-split data sample. The selected prediction model was used to generate a risk score, and its ability to differentiate ART failure risk over a 42-month follow-up period was tested using stratified Kaplan Meier survival curves. Results Among 923 patients with CD4 results available during the period 6–12 months after ART initiation, 196 (21.2%) met ART failure criteria. The pharmacy-based proportion of days covered (PDC) measure performed best among five possible ART adherence measures at predicting ART failure. Average PDC during the first 6 months on ART was 79.0% among cases of ART failure and 88.6% among cases of non-failure (pART initiation were added to PDC, the risk score differentiated between those who did and did not meet failure criteria over 42 months following ART initiation. Conclusions Pharmacy data are most useful for new ART adherence alerts within iSanté. Such alerts offer potential to help clinicians identify patients at high risk of ART failure so that they can be targeted with adherence support interventions, before ART failure occurs. PMID:25390044

  18. Development of an electronic medical record based alert for risk of HIV treatment failure in a low-resource setting.

    Directory of Open Access Journals (Sweden)

    Nancy Puttkammer

    Full Text Available The adoption of electronic medical record systems in resource-limited settings can help clinicians monitor patients' adherence to HIV antiretroviral therapy (ART and identify patients at risk of future ART failure, allowing resources to be targeted to those most at risk.Among adult patients enrolled on ART from 2005-2013 at two large, public-sector hospitals in Haiti, ART failure was assessed after 6-12 months on treatment, based on the World Health Organization's immunologic and clinical criteria. We identified models for predicting ART failure based on ART adherence measures and other patient characteristics. We assessed performance of candidate models using area under the receiver operating curve, and validated results using a randomly-split data sample. The selected prediction model was used to generate a risk score, and its ability to differentiate ART failure risk over a 42-month follow-up period was tested using stratified Kaplan Meier survival curves.Among 923 patients with CD4 results available during the period 6-12 months after ART initiation, 196 (21.2% met ART failure criteria. The pharmacy-based proportion of days covered (PDC measure performed best among five possible ART adherence measures at predicting ART failure. Average PDC during the first 6 months on ART was 79.0% among cases of ART failure and 88.6% among cases of non-failure (p<0.01. When additional information including sex, baseline CD4, and duration of enrollment in HIV care prior to ART initiation were added to PDC, the risk score differentiated between those who did and did not meet failure criteria over 42 months following ART initiation.Pharmacy data are most useful for new ART adherence alerts within iSanté. Such alerts offer potential to help clinicians identify patients at high risk of ART failure so that they can be targeted with adherence support interventions, before ART failure occurs.

  19. Innovative direct energy conversion systems using electronic adiabatic processes of electron fluid in solid conductors: new plants of electrical power and hydrogen gas resources without environmental pollutions

    International Nuclear Information System (INIS)

    Kondoh, Y.; Kondo, M.; Shimoda, K.; Takahashi, T.

    2001-07-01

    It is shown that using a novel recycling process of the environmental thermal energy, innovative permanent auto-working direct energy converter systems (PA-DEC systems) from the environmental thermal to electrical and/or chemical potential (TE/CP) energies, abbreviated as PA-TE/CP-DEC systems, can be used for new auto-working electrical power plants and the plants of the compressible and conveyable hydrogen gas resources at various regions in the whole world, with contributions to the world peace and the economical development in the south part of the world. It is shown that the same physical mechanism by free electrons and electrical potential determined by temperature in conductors, which include semiconductors, leads to the Peltier effect and the Seebeck one. It is experimentally clarified that the long distance separation between two π type elements of the heat absorption (HAS) and the production one (HPS) of the Peltier effect circuit system or between the higher temperature side (HTS) and the lower one (LTS) of the Seebeck effect circuit one does not change in the whole for the both effects. By using present systems, we do not need to use petrified fuels such as coals, oils, and natural gases in order to decrease the greenhouse effect by the CO 2 surrounding the earth. Furthermore, we do not need plats of nuclear fissions that left radiating wastes, i.e., with no environmental pollutions. The PA-TE/CP-DEC systems can be applicable for several km scale systems to the micro ones, such as the plants of the electrical power, the compact transportable hydrogen gas resources, a large heat energy container, which can be settled at far place from thermal energy absorbing area, the refrigerators, the air conditioners, home electrical apparatuses, and further the computer elements. It is shown that the simplest PA-TE/CP-DEC system can be established by using only the Seebeck effect components and the resolving water ones. It is clarified that the externally applied

  20. Smart electrochemical biosensors: From advanced materials to ultrasensitive devices

    Energy Technology Data Exchange (ETDEWEB)

    Sadik, Omowunmi A., E-mail: osadik@binghamton.ed [Department of Chemistry, Center for Advanced Sensors and Environmental Monitoring (CASE), State University of New York-Binghamton, P.O. Box 6000, Binghamton, NY 13902 (United States); Mwilu, Samuel K.; Aluoch, Austin [Department of Chemistry, Center for Advanced Sensors and Environmental Monitoring (CASE), State University of New York-Binghamton, P.O. Box 6000, Binghamton, NY 13902 (United States)

    2010-05-30

    The specificity, simplicity, and inherent miniaturization afforded by advances in modern electronics have allowed electrochemical sensors to rival the most advanced optical protocols. One major obstacle in implementing electrochemistry for studying biomolecular reaction is its inadequate sensitivity. Recent reports however showed unprecedented sensitivities for biomolecular recognition using enhanced electronic amplification provided by new classes of electrode materials (e.g. carbon nanotubes, metal nanoparticles, and quantum dots). Biosensor technology is one area where recent advances in nanomaterials are pushing the technological limits of electrochemical sensitivities, thus allowing for the development of new sensor chemistries and devices. This work focuses on our recent work, based on metal-enhanced electrochemical detection, and those of others in combining advanced nanomaterials with electrochemistry for the development of smart sensors for proteins, nucleic acids, drugs and cancer cells.

  1. Smart electrochemical biosensors: From advanced materials to ultrasensitive devices

    International Nuclear Information System (INIS)

    Sadik, Omowunmi A.; Mwilu, Samuel K.; Aluoch, Austin

    2010-01-01

    The specificity, simplicity, and inherent miniaturization afforded by advances in modern electronics have allowed electrochemical sensors to rival the most advanced optical protocols. One major obstacle in implementing electrochemistry for studying biomolecular reaction is its inadequate sensitivity. Recent reports however showed unprecedented sensitivities for biomolecular recognition using enhanced electronic amplification provided by new classes of electrode materials (e.g. carbon nanotubes, metal nanoparticles, and quantum dots). Biosensor technology is one area where recent advances in nanomaterials are pushing the technological limits of electrochemical sensitivities, thus allowing for the development of new sensor chemistries and devices. This work focuses on our recent work, based on metal-enhanced electrochemical detection, and those of others in combining advanced nanomaterials with electrochemistry for the development of smart sensors for proteins, nucleic acids, drugs and cancer cells.

  2. Recent Progress in Lectin-Based Biosensors

    Directory of Open Access Journals (Sweden)

    Baozhen Wang

    2015-12-01

    Full Text Available This article reviews recent progress in the development of lectin-based biosensors used for the determination of glucose, pathogenic bacteria and toxins, cancer cells, and lectins. Lectin proteins have been widely used for the construction of optical and electrochemical biosensors by exploiting the specific binding affinity to carbohydrates. Among lectin proteins, concanavalin A (Con A is most frequently used for this purpose as glucose- and mannose-selective lectin. Con A is useful for immobilizing enzymes including glucose oxidase (GOx and horseradish peroxidase (HRP on the surface of a solid support to construct glucose and hydrogen peroxide sensors, because these enzymes are covered with intrinsic hydrocarbon chains. Con A-modified electrodes can be used as biosensors sensitive to glucose, cancer cells, and pathogenic bacteria covered with hydrocarbon chains. The target substrates are selectively adsorbed to the surface of Con A-modified electrodes through strong affinity of Con A to hydrocarbon chains. A recent topic in the development of lectin-based biosensors is a successful use of nanomaterials, such as metal nanoparticles and carbon nanotubes, for amplifying output signals of the sensors. In addition, lectin-based biosensors are useful for studying glycan expression on living cells.

  3. S-Layer Protein-Based Biosensors

    Directory of Open Access Journals (Sweden)

    Bernhard Schuster

    2018-04-01

    Full Text Available The present paper highlights the application of bacterial surface (S- layer proteins as versatile components for the fabrication of biosensors. One technologically relevant feature of S-layer proteins is their ability to self-assemble on many surfaces and interfaces to form a crystalline two-dimensional (2D protein lattice. The S-layer lattice on the surface of a biosensor becomes part of the interface architecture linking the bioreceptor to the transducer interface, which may cause signal amplification. The S-layer lattice as ultrathin, highly porous structure with functional groups in a well-defined special distribution and orientation and an overall anti-fouling characteristics can significantly raise the limit in terms of variety and the ease of bioreceptor immobilization, compactness of bioreceptor molecule arrangement, sensitivity, specificity, and detection limit for many types of biosensors. The present paper discusses and summarizes examples for the successful implementation of S-layer lattices on biosensor surfaces in order to give a comprehensive overview on the application potential of these bioinspired S-layer protein-based biosensors.

  4. S-Layer Protein-Based Biosensors.

    Science.gov (United States)

    Schuster, Bernhard

    2018-04-11

    The present paper highlights the application of bacterial surface (S-) layer proteins as versatile components for the fabrication of biosensors. One technologically relevant feature of S-layer proteins is their ability to self-assemble on many surfaces and interfaces to form a crystalline two-dimensional (2D) protein lattice. The S-layer lattice on the surface of a biosensor becomes part of the interface architecture linking the bioreceptor to the transducer interface, which may cause signal amplification. The S-layer lattice as ultrathin, highly porous structure with functional groups in a well-defined special distribution and orientation and an overall anti-fouling characteristics can significantly raise the limit in terms of variety and the ease of bioreceptor immobilization, compactness of bioreceptor molecule arrangement, sensitivity, specificity, and detection limit for many types of biosensors. The present paper discusses and summarizes examples for the successful implementation of S-layer lattices on biosensor surfaces in order to give a comprehensive overview on the application potential of these bioinspired S-layer protein-based biosensors.

  5. Biosensors for Sustainable Food Engineering: Challenges and Perspectives

    Science.gov (United States)

    Ragavan, Vasanth; Weng, Xuan; Chand, Rohit

    2018-01-01

    Current food production faces tremendous challenges from growing human population, maintaining clean resources and food qualities, and protecting climate and environment. Food sustainability is mostly a cooperative effort resulting in technology development supported by both governments and enterprises. Multiple attempts have been promoted in tackling challenges and enhancing drivers in food production. Biosensors and biosensing technologies with their applications, are being widely applied to tackling top challenges in food production and its sustainability. Consequently, a growing demand in biosensing technologies exists in food sustainability. Microfluidics represents a technological system integrating multiple technologies. Nanomaterials, with its technology in biosensing, is thought to be the most promising tool in dealing with health, energy, and environmental issues closely related to world populations. The demand of point of care (POC) technologies in this area focus on rapid, simple, accurate, portable, and low-cost analytical instruments. This review provides current viewpoints from the literature on biosensing in food production, food processing, safety and security, food packaging and supply chain, food waste processing, food quality assurance, and food engineering. The current understanding of progress, solution, and future challenges, as well as the commercialization of biosensors are summarized. PMID:29534552

  6. Biosensors for Sustainable Food Engineering: Challenges and Perspectives.

    Science.gov (United States)

    Neethirajan, Suresh; Ragavan, Vasanth; Weng, Xuan; Chand, Rohit

    2018-03-12

    Current food production faces tremendous challenges from growing human population, maintaining clean resources and food qualities, and protecting climate and environment. Food sustainability is mostly a cooperative effort resulting in technology development supported by both governments and enterprises. Multiple attempts have been promoted in tackling challenges and enhancing drivers in food production. Biosensors and biosensing technologies with their applications, are being widely applied to tackling top challenges in food production and its sustainability. Consequently, a growing demand in biosensing technologies exists in food sustainability. Microfluidics represents a technological system integrating multiple technologies. Nanomaterials, with its technology in biosensing, is thought to be the most promising tool in dealing with health, energy, and environmental issues closely related to world populations. The demand of point of care (POC) technologies in this area focus on rapid, simple, accurate, portable, and low-cost analytical instruments. This review provides current viewpoints from the literature on biosensing in food production, food processing, safety and security, food packaging and supply chain, food waste processing, food quality assurance, and food engineering. The current understanding of progress, solution, and future challenges, as well as the commercialization of biosensors are summarized.

  7. A novel glucose biosensor based on phosphonic acid-functionalized silica nanoparticles for sensitive detection of glucose in real samples

    International Nuclear Information System (INIS)

    Zhao, Wenbo; Fang, Yi; Zhu, Qinshu; Wang, Kuai; Liu, Min; Huang, Xiaohua; Shen, Jian

    2013-01-01

    An effective strategy for preparation amperometric biosensor by using the phosphonic acid-functionalized silica nanoparticles (PFSi NPs) as special modified materials is proposed. In such a strategy, glucose oxidase (GOD) was selected as model protein to fabricate glucose biosensor in the presence of phosphonic acid-functionalized silica nanoparticles (PFSi NPs). The PFSi NPs were first modified on the surface of glassy carbon (GC) electrode, then, GOD was adsorbed onto the PFSi NPs film by drop-coating. The PFSi NPs were characterized by transmission electron microscopy (TEM) and nuclear magnetic resonance (NMR) spectra. The interaction of PFSi NPs with GOD was investigated by the circular dicroism spectroscopy (CD). The results showed PFSi NPs could essentially maintain the native conformation of GOD. The direct electron transfer of GOD on (PFSi NPs)/GCE electrode exhibited excellent electrocatalytic activity for the oxidation of glucose. The proposed biosensor modified with PFSi NPs displayed a fast amperometric response (5 s) to glucose, a good linear current–time relation over a wide range of glucose concentrations from 5.00 × 10 −4 to 1.87 × 10 −1 M, and a low detection limit of 2.44 × 10 −5 M (S/N = 3). Moreover, the biosensor can be used for assessment of the concentration of glucose in many real samples (relative error < 3%). The GOD biosensor modified with PFSi NPs will have essential meaning and practical application in future that attributed to the simple method of fabrication and good performance

  8. Highly sensitive amperometric biosensor based on electrochemically-reduced graphene oxide-chitosan/hemoglobin nanocomposite for nitromethane determination.

    Science.gov (United States)

    Wen, Yunping; Wen, Wei; Zhang, Xiuhua; Wang, Shengfu

    2016-05-15

    Nitromethane (CH3NO2) is an important organic chemical raw material with a wide variety of applications as well as one of the most common pollutants. Therefore it is pretty important to establish a simple and sensitive detection method for CH3NO2. In our study, a novel amperometric biosensor for nitromethane (CH3NO2) based on immobilization of electrochemically-reduced graphene oxide (rGO), chitosan (CS) and hemoglobin (Hb) on a glassy carbon electrode (GCE) was constructed. Scanning electron microscopy, infrared spectroscopy and electrochemical methods were used to characterize the Hb-CS/rGO-CS composite film. The effects of scan rate and pH of phosphate buffer on the biosensor have been studied in detail and optimized. Due to the graphene and chitosan nanocomposite, the developed biosensor demonstrating direct electrochemistry with faster electron-transfer rate (6.48s(-1)) and excellent catalytic activity towards CH3NO2. Under optimal conditions, the proposed biosensor exhibited fast amperometric response (<5s) to CH3NO2 with a wide linear range of 5 μM~1.46 mM (R=0.999) and a low detection limit of 1.5 μM (S/N=3). In addition, the biosensor had high selectivity, reproducibility and stability, providing the possibility for monitoring CH3NO2 in complex real samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Influences of Mg Doping on the Electrochemical Performance of TiO2 Nanodots Based Biosensor Electrodes

    Directory of Open Access Journals (Sweden)

    M. S. H. Al-Furjan

    2014-01-01

    Full Text Available Electrochemical biosensors are essential for health monitors to help in diagnosis and detection of diseases. Enzyme adsorptions on biosensor electrodes and direct electron transfer between them have been recognized as key factors to affect biosensor performance. TiO2 has a good protein adsorption ability and facilitates having more enzyme adsorption and better electron transfer. In this work, Mg ions are introduced into TiO2 nanodots in order to further improve electrode performance because Mg ions are considered to have good affinity with proteins or enzymes. Mg doped TiO2 nanodots on Ti substrates were prepared by spin-coating and calcining. The effects of Mg doping on the nanodots morphology and performance of the electrodes were investigated. The density and size of TiO2 nanodots were obviously changed with Mg doping. The sensitivity of 2% Mg doped TiO2 nanodots based biosensor electrode increased to 1377.64 from 897.8 µA mM−1 cm−2 and its KMapp decreases to 0.83 from 1.27 mM, implying that the enzyme achieves higher catalytic efficiency due to better affinity of the enzyme with the Mg doped TiO2. The present work could provide an alternative to improve biosensor performances.

  10. Consumer reports [electronic resource

    National Research Council Canada - National Science Library

    1942-01-01

    ... only. A limited number of selected reports, advice on product selection and safety alerts are freely available, as are a five year listing of product recalls, a listing of major consumer product...

  11. Functional design of electrolytic biosensor

    Science.gov (United States)

    Gamage Preethichandra, D. M.; Mala Ekanayake, E. M. I.; Onoda, M.

    2017-11-01

    A novel amperometric biosensbased on conjugated polypyrrole (PPy) deposited on a Pt modified ITO (indium tin oxide) conductive glass substrate and their performances are described. We have presented a method of developing a highly sensitive and low-cost nano-biosensor for blood glucose measurements. The fabrication method proposed decreases the cost of production significantly as the amount of noble metals used is minimized. A nano-corrugated PPy substrate was developed through pulsed electrochemical deposition. The sensitivity achieved was 325 mA/(Mcm2) and the linear range of the developed sensor was 50-60 mmol/l. Then the application of the electrophoresis helps the glucose oxidase (GOx) on the PPy substrate. The main reason behind this high enzyme loading is the high electric field applied across the sensor surface (working electrode) and the counter electrode where that pushes the nano-scale enzyme particles floating in the phosphate buffer solution towards the substrate. The novel technique used has provided an extremely high sensitivities and very high linear ranges for enzyme (GOx) and therefore can be concluded that this is a very good technique to load enzyme onto the conducting polymer substrates.

  12. Magnetoresistive biosensors for quantitative proteomics

    Science.gov (United States)

    Zhou, Xiahan; Huang, Chih-Cheng; Hall, Drew A.

    2017-08-01

    Quantitative proteomics, as a developing method for study of proteins and identification of diseases, reveals more comprehensive and accurate information of an organism than traditional genomics. A variety of platforms, such as mass spectrometry, optical sensors, electrochemical sensors, magnetic sensors, etc., have been developed for detecting proteins quantitatively. The sandwich immunoassay is widely used as a labeled detection method due to its high specificity and flexibility allowing multiple different types of labels. While optical sensors use enzyme and fluorophore labels to detect proteins with high sensitivity, they often suffer from high background signal and challenges in miniaturization. Magnetic biosensors, including nuclear magnetic resonance sensors, oscillator-based sensors, Hall-effect sensors, and magnetoresistive sensors, use the specific binding events between magnetic nanoparticles (MNPs) and target proteins to measure the analyte concentration. Compared with other biosensing techniques, magnetic sensors take advantage of the intrinsic lack of magnetic signatures in biological samples to achieve high sensitivity and high specificity, and are compatible with semiconductor-based fabrication process to have low-cost and small-size for point-of-care (POC) applications. Although still in the development stage, magnetic biosensing is a promising technique for in-home testing and portable disease monitoring.

  13. The field effect transistor DNA biosensor based on ITO nanowires in label-free hepatitis B virus detecting compatible with CMOS technology.

    Science.gov (United States)

    Shariati, Mohsen

    2018-05-15

    In this paper the field-effect transistor DNA biosensor for detecting hepatitis B virus (HBV) based on indium tin oxide nanowires (ITO NWs) in label free approach has been fabricated. Because of ITO nanowires intensive conductance and functional modified surface, the probe immobilization and target hybridization were increased strongly. The high resolution transmission electron microscopy (HRTEM) measurement showed that ITO nanowires were crystalline and less than 50nm in diameter. The single-stranded hepatitis B virus DNA (SS-DNA) was immobilized as probe on the Au-modified nanowires. The DNA targets were measured in a linear concentration range from 1fM to 10µM. The detection limit of the DNA biosensor was about 1fM. The time of the hybridization process for defined single strand was 90min. The switching ratio of the biosensor between "on" and "off" state was ~ 1.1 × 10 5 . For sensing the specificity of the biosensor, non-complementary, mismatch and complementary DNA oligonucleotide sequences were clearly discriminated. The HBV biosensor confirmed the highly satisfied specificity for differentiating complementary sequences from non-complementary and the mismatch oligonucleotides. The response time of the DNA sensor was 37s with a high reproducibility. The stability and repeatability of the DNA biosensor showed that the peak current of the biosensor retained 98% and 96% of its initial response for measurements after three and five weeks, respectively. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Advanced biosensors for monitoring astronauts' health during long-duration space missions.

    Science.gov (United States)

    Roda, Aldo; Mirasoli, Mara; Guardigli, Massimo; Zangheri, Martina; Caliceti, Cristiana; Calabria, Donato; Simoni, Patrizia

    2018-07-15

    Long-duration space missions pose important health concerns for astronauts, especially regarding the adverse effects of microgravity and exposure to high-energy cosmic rays. The long-term maintenance of crew health and performance mainly relies on prevention, early diagnoses, condition management, and medical interventions in situ. In-flight biosensor diagnostic devices and medical procedures must use few resources and operate in a microgravity environment, which complicates the collection and management of biological samples. Moreover, the biosensors must be certified for in-flight operation according to strict design and safety regulations. Herein, we report on the state of the art and recent advances in biosensing diagnostic instrumentation for monitoring astronauts' health during long-duration space missions, including portable and wearable biosensors. We discuss perspectives on new-format biosensors in autonomous space clinics. We also describe our own work in developing biosensing devices for non-invasively diagnosing space-related diseases, and how they are used in long-duration missions. Finally, we discuss the benefits of space exploration for Earth-based medicine. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. The electronic Rothamsted Archive (e-RA), an online resource for data from the Rothamsted long-term experiments.

    Science.gov (United States)

    Perryman, Sarah A M; Castells-Brooke, Nathalie I D; Glendining, Margaret J; Goulding, Keith W T; Hawkesford, Malcolm J; Macdonald, Andy J; Ostler, Richard J; Poulton, Paul R; Rawlings, Christopher J; Scott, Tony; Verrier, Paul J

    2018-05-15

    The electronic Rothamsted Archive, e-RA (www.era.rothamsted.ac.uk) provides a permanent managed database to both securely store and disseminate data from Rothamsted Research's long-term field experiments (since 1843) and meteorological stations (since 1853). Both historical and contemporary data are made available via this online database which provides the scientific community with access to a unique continuous record of agricultural experiments and weather measured since the mid-19 th century. Qualitative information, such as treatment and management practices, plans and soil information, accompanies the data and are made available on the e-RA website. e-RA was released externally to the wider scientific community in 2013 and this paper describes its development, content, curation and the access process for data users. Case studies illustrate the diverse applications of the data, including its original intended purposes and recent unforeseen applications. Usage monitoring demonstrates the data are of increasing interest. Future developments, including adopting FAIR data principles, are proposed as the resource is increasingly recognised as a unique archive of data relevant to sustainable agriculture, agroecology and the environment.

  16. Hydrogen peroxide biosensor based on titanium oxide

    Science.gov (United States)

    Halim, Nur Hamidah Abdul; Heng, Lee Yook; Hashim, Uda

    2015-09-01

    In this work, a biosensor utilizing modified titania, TiO2 particles using aminopropyl-triethoxy-silane, (APTS) for developing hydrogen peroxide biosensor is presented. The surface of Ti-APTS particles is used as a support for hemoglobin immobilization via covalent bonding. The performance of the biosensor is determined by differential pulse voltammetry. The linear response was observed at the reduction current of redox mediator probe [FeCN6]3-/4- at potential between 0.22 V to 0.24 V. The preliminary result for electrochemistry study on this modified electrode is reported. The preliminary linear range is obtained from 1×10-2 M to 1×10-8 M.

  17. An improved amperometric creatinine biosensor based on nanoparticles of creatininase, creatinase and sarcosine oxidase.

    Science.gov (United States)

    Kumar, Parveen; Jaiwal, Ranjana; Pundir, C S

    2017-11-15

    An improved amperometric biosensor for detection of creatinine was developed based on immobilization of nanoparticles (NPs) of creatininase (CA), creatinase (CI), and sarcosine oxidase (SOx) onto glassy carbon (GC) electrode. Transmission electron microscopy (TEM) and fourier transform infrared spectroscopy (FTIR) were employed for characterization of enzyme nanoparticles (ENPs). The GC electrode was characterized by scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectra (EIS) at different stages of its amendment. The biosensor showed optimum response within 2s at pH 6.0 in 0.1 M sodium phosphate buffer and 25 °C, when operated at 1.0 V against Ag/AgCl. Biosensor exhibited wider linear range from 0.01 μM to 12 μM with a limit of detection (LOD) of 0.01 μM. The analytical recoveries of added creatinine in sera were 97.97 ± 0.1% for 0.1 mM and 98.76 ± 0.2% for 0.15 mM, within and between batch coefficients of variation (CV) were 2.06% and 3.09% respectively. A good correlation (R 2  = 0.99) was observed between sera creatinine values obtained by standard enzymic colorimetric method and the present biosensor. This biosensor measured creatinine level in sera of apparently healthy subjects and persons suffering from renal and muscular dysfunction. The ENPs electrode lost 10% of its initial activity within 240 days of its regular uses, when stored at 4 °C. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. A DNA biosensor for molecular diagnosis of Aeromonas hydrophila using zinc sulfide nanospheres

    Directory of Open Access Journals (Sweden)

    M. Negahdary

    2017-07-01

    Full Text Available Today, identification of pathogenic bacteria using modern and accurate methods is inevitable. Integration in electrochemical measurements with nanotechnology has led to the design of efficient and sensitive DNA biosensors against bacterial agents. Here, efforts were made to detect Aeromonas hydrophila using aptamers as probes and zinc sulfide (ZnS nanospheres as signal enhancers and electron transfer facilitators. After modification of the working electrode area (in a screen-printed electrode with ZnS nanospheres through electrodeposition, the coated surface of a modified electrode with ZnS nanospheres was investigated through scanning electron microscopy (SEM. The size of synthesized ZnS nanospheres was estimated at about 20–50 nm and their shape was in the form of porous plates in microscopic observations. All electrochemical measurements were performed using cyclic voltammetry (CV, electrochemical impedance spectroscopy (EIS, and constant potential amperometry (CPA techniques. The designed DNA biosensor was able to detect deoxyribonucleic acid (DNA of Aeromonas hydrophila in the range 1.0  ×  10−4 to 1.0  ×  10−9 mol L−1; the limit of detection (LOD in this study was 1  ×  10−13 mol L−1. This DNA biosensor showed satisfactory thermal and pH stability. Reproducibility for this DNA biosensor was measured and the relative standard deviation (RSD of the performance of this DNA biosensor was calculated as 5 % during 42 days.

  19. Principles of formation of the content of an educational electronic resource on the basis of general and didactic patterns of learning

    Directory of Open Access Journals (Sweden)

    Ольга Юрьевна Заславская

    2018-12-01

    Full Text Available The article considers the influence of the development of technical means of teaching on the effectiveness of educational and methodical resources. Modern opportunities of information and communication technologies allow creating electronic educational resources that represent educational information that automates the learning process, provide information assistance, if necessary, collect and process statistical information on the degree of development of the content of the school material by schoolchildren, set an individual trajectory of learning, and so on. The main principle of data organization is the division of the training course into separate sections on the thematic elements and components of the learning process. General regularities include laws that encompass the entire didactic system, and in specific (particular cases, those whose actions extend to a separate component (aspect of the system. From the standpoint of the existence of three types of electronic training modules in the aggregate content of the electronic learning resource - information, control and module of practical classes - the principles of the formation of the electronic learning resource, in our opinion, should regulate all these components. Each of the certain principles is considered in the groups: scientific orientation, methodological orientation, systemic nature, accounting of interdisciplinary connections, fundamentalization, systematic and dosage sequence, rational use of study time, accessibility, minimization, operationalization of goals, unified identification diagnosis.

  20. The module of methodical support in system of electronic educational resources as the innovative element of the modern maintenance of formation

    Directory of Open Access Journals (Sweden)

    Ольга Николаевна Крылова

    2009-06-01

    Full Text Available The article introduces some results of research, which were devoted to evaluation of tearches' mobility to introduce innovations in the contents of education. The author considers innovative potential of modules of the methodical support for system of electronic educational resources.

  1. Charting a Course through CORAL: Texas A&M University Libraries' Experience Implementing an Open-Source Electronic Resources Management System

    Science.gov (United States)

    Hartnett, Eric; Beh, Eugenia; Resnick, Taryn; Ugaz, Ana; Tabacaru, Simona

    2013-01-01

    In 2010, after two previous unsuccessful attempts at electronic resources management system (ERMS) implementation, Texas A&M University (TAMU) Libraries set out once again to find an ERMS that would fit its needs. After surveying the field, TAMU Libraries selected the University of Notre Dame Hesburgh Libraries-developed, open-source ERMS,…

  2. Aryl Diazonium Chemistry for the Surface Functionalization of Glassy Biosensors

    Directory of Open Access Journals (Sweden)

    Wei Zheng

    2016-03-01

    Full Text Available Nanostring resonator and fiber-optics-based biosensors are of interest as they offer high sensitivity, real-time measurements and the ability to integrate with electronics. However, these devices are somewhat impaired by issues related to surface modification. Both nanostring resonators and photonic sensors employ glassy materials, which are incompatible with electrochemistry. A surface chemistry approach providing strong and stable adhesion to glassy surfaces is thus required. In this work, a diazonium salt induced aryl film grafting process is employed to modify a novel SiCN glassy material. Sandwich rabbit IgG binding assays are performed on the diazonium treated SiCN surfaces. Fluorescently labelled anti-rabbit IgG and anti-rabbit IgG conjugated gold nanoparticles were used as markers to demonstrate the absorption of anti-rabbit IgG and therefore verify the successful grafting of the aryl film. The results of the experiments support the effectiveness of diazonium chemistry for the surface functionalization of SiCN surfaces. This method is applicable to other types of glassy materials and potentially can be expanded to various nanomechanical and optical biosensors.

  3. Aryl Diazonium Chemistry for the Surface Functionalization of Glassy Biosensors.

    Science.gov (United States)

    Zheng, Wei; van den Hurk, Remko; Cao, Yong; Du, Rongbing; Sun, Xuejun; Wang, Yiyu; McDermott, Mark T; Evoy, Stephane

    2016-03-14

    Nanostring resonator and fiber-optics-based biosensors are of interest as they offer high sensitivity, real-time measurements and the ability to integrate with electronics. However, these devices are somewhat impaired by issues related to surface modification. Both nanostring resonators and photonic sensors employ glassy materials, which are incompatible with electrochemistry. A surface chemistry approach providing strong and stable adhesion to glassy surfaces is thus required. In this work, a diazonium salt induced aryl film grafting process is employed to modify a novel SiCN glassy material. Sandwich rabbit IgG binding assays are performed on the diazonium treated SiCN surfaces. Fluorescently labelled anti-rabbit IgG and anti-rabbit IgG conjugated gold nanoparticles were used as markers to demonstrate the absorption of anti-rabbit IgG and therefore verify the successful grafting of the aryl film. The results of the experiments support the effectiveness of diazonium chemistry for the surface functionalization of SiCN surfaces. This method is applicable to other types of glassy materials and potentially can be expanded to various nanomechanical and optical biosensors.

  4. Electrochemical DNA biosensor based on the BDD nanograss array electrode.

    Science.gov (United States)

    Jin, Huali; Wei, Min; Wang, Jinshui

    2013-04-10

    The development of DNA biosensor has attracted considerable attention due to their potential applications, including gene analysis, clinical diagnostics, forensic study and more medical applications. Using electroactive daunomycin as an indicator, the hybridization detection was measured by differential pulse voltammetry in this study. Electrochemical DNA biosensor was developed based on the BDD film electrode (fBDD) and BDD nanograss array electrode (nBDD). In comparison with fBDD and AuNPs/CA/fBDD electrode, the lower semicircle diameter of electrochemical impedance spectroscopy obtained on nBDD and AuNPs/CA/nBDD electrode indicated that the presence of nanograss array improved the reactive site, reduced the interfacial resistance, and made the electron transfer easier. Using electroactive daunomycin as an indicator, the hybridization detection was measured by differential pulse voltammetry. The experimental results demonstrated that the prepared AuNPs/CA/nBDD electrode was suitable for DNA hybridization with favorable performance of faster response, higher sensitivity, lower detection limit and satisfactory selectivity, reproducibility and stability.

  5. A new miniaturized multiarray biosensor system for fluorescence detection

    International Nuclear Information System (INIS)

    Tibuzzi, A; Rea, G; Pezzotti, G; Esposito, D; Johanningmeier, U; Giardi, M T

    2007-01-01

    A miniaturized biosensor-based optical instrument has been designed and fabricated for multiarray fluorescence measurements of several biomediators in series, with applications in environmental monitoring and agrofood analysis. It is a multicell system featuring two arrays of five static cells (1 x 1 x 2 cm 3 ) which are sealed to avoid contamination. Every cell is made up by two modular sections: the bottom compartment with optical LED light excitations and a photodiode detector for fluorescence emission capture, and the top biocompatible compartment where the biosample is deposited. The system (0.250 kg without batteries and case, 100 x 100 x 150 mm 3 internal case dimensions) is equipped with electronic control boards, a flash memory card for automatic data storage, and internal batteries, thus being portable and versatile. The instrument allows one to perform simultaneous and multiparametric analyses and offers a large applicability in biosensor technology. The first prototype has been implemented with genetically modified oxygenic photosynthetic algae that were employed in the instrument experimental testing by monitoring pesticide pollution in water. Pesticides modify the photosystem II (PSII) activity in terms of fluorescence quenching. The PSII complex features a natural nanostructure and can be considered a sophisticated molecular device. Results from measurements employing several PSII mutants and six different pesticides at increasing concentrations and incubation times are presented and discussed

  6. Potentiometric urea biosensor based on multi-walled carbon nanotubes (MWCNTs)/silica composite material

    International Nuclear Information System (INIS)

    Ahuja, Tarushee; Kumar, D.; Singh, Nahar; Biradar, A.M.; Rajesh

    2011-01-01

    A novel potentiometric urea biosensor has been fabricated with urease (Urs) immobilized multi-walled carbon nanotubes (MWCNTs) embedded in silica matrix deposited on the surface of indium tin oxide (ITO) coated glass plate. The enzyme Urs was covalently linked with the exposed free -COOH groups of functionalized MWCNTs (F-MWCNTs), which are subsequently incorporated within the silica matrix by sol-gel method. The Urs/MWCNTs/SiO 2 /ITO composite modified electrode was characterized by Fourier transform infrared (FTIR) spectroscopy, thermal gravimetric analysis (TGA) and UV-visible spectroscopy. The morphologies and electrochemical performance of the modified Urs/MWCNTs/SiO 2 /ITO electrode have been investigated by scanning electron microscopy (SEM) and potentiometric method, respectively. The synergistic effect of silica matrix, F-MWCNTs and biocompatibility of Urs/MWCNTs/SiO 2 made the biosensor to have the excellent electro catalytic activity and high stability. The resulting biosensor exhibits a good response performance to urea detection with a wide linear range from 2.18 x 10 -5 to 1.07 x 10 -3 M urea. The biosensor shows a short response time of 10-25 s and a high sensitivity of 23 mV/decade/cm 2 .

  7. Poly(1-(2-carboxyethyl)pyrrole)/polypyrrole composite nanowires for glucose biosensor

    International Nuclear Information System (INIS)

    Jiang Hairong; Zhang Aifeng; Sun Yanan; Ru Xiaoning; Ge Dongtao; Shi Wei

    2012-01-01

    A novel glucose biosensor based on poly(1-(2-carboxyethyl)pyrrole) (PPyCOOH)/polypyrrole (PPy) composite nanowires was developed by immobilizing glucose oxidase (GOD) on the nanowires via covalent linkages. The PPyCOOH/PPy composite nanowires were fabricated by a facile two-step electrochemical synthesis route. First, PPy nanowires were synthesized in phosphate buffer solution using organic sulfonic acid, p-toluenesulfonate acid, as soft-template. Then, PPyCOOH/PPy composite nanowires were obtained by polymerizing 1-(2-carboxyethyl)pyrrole onto PPy nanowires via electrochemical method. Scanning electron microscopic, FT-IR spectra, X-ray photoelectron spectroscopy and cyclic voltammograms were used to characterize the structural and electrical behaviors of the composite nanowires. The PPyCOOH/PPy composite nanowires exhibited uniform diameter, high reactive site (-COOH), large specific surface, excellent electroactivity and good adhesion to electrode. The glucose biosensor was constructed by covalently coupling GOD to the composite nanowires. The biosensor response was rapid (5 s), highly sensitive (33.6 μA mM −1 cm −2 ) with a wide linear range (up to 10.0 mM) and low detection limit (0.63 μM); it also exhibited high stability and specificity to glucose. The attractive electrochemical and structural properties of PPyCOOH/PPy composite nanowires suggested potential application for electrocatalysis and biosensor.

  8. Development of an acoustic wave based biosensor for vapor phase detection of small molecules

    Science.gov (United States)

    Stubbs, Desmond

    For centuries scientific ingenuity and innovation have been influenced by Mother Nature's perfect design. One of her more elusive designs is that of the sensory olfactory system, an array of highly sensitive receptors responsible for chemical vapor recognition. In the animal kingdom this ability is magnified among canines where ppt (parts per trillion) sensitivity values have been reported. Today, detection dogs are considered an essential part of the US drug and explosives detection schemes. However, growing concerns about their susceptibility to extraneous odors have inspired the development of highly sensitive analytical detection tools or biosensors known as "electronic noses". In general, biosensors are distinguished from chemical sensors in that they use an entity of biological origin (e.g. antibody, cell, enzyme) immobilized onto a surface as the chemically-sensitive film on the device. The colloquial view is that the term "biosensors" refers to devices which detect the presence of entities of biological origin, such as proteins or single-stranded DNA and that this detection must take place in a liquid. Our biosensor utilizes biomolecules, specifically IgG monoclonal antibodies, to achieve molecular recognition of relatively small molecules in the vapor phase.

  9. Graphene, carbon nanotubes, zinc oxide and gold as elite nanomaterials for fabrication of biosensors for healthcare.

    Science.gov (United States)

    Kumar, Sandeep; Ahlawat, Wandit; Kumar, Rajesh; Dilbaghi, Neeraj

    2015-08-15

    Technological advancements worldwide at rapid pace in the area of materials science and nanotechnology have made it possible to synthesize nanoparticles with desirable properties not exhibited by the bulk material. Among variety of available nanomaterials, graphene, carbon nanotubes, zinc oxide and gold nanopartilces proved to be elite and offered amazing electrochemical biosensing. This encourages us to write a review which highlights the recent achievements in the construction of genosensor, immunosensor and enzymatic biosensor based on the above nanomaterials. Carbon based nanomaterials offers a direct electron transfer between the functionalized nanomaterials and active site of bioreceptor without involvement of any mediator which not only amplifies the signal but also provide label free sensing. Gold shows affinity towards immunological molecules and is most routinely used for immunological sensing. Zinc oxide can easily immobilize proteins and hence offers a large group of enzyme based biosensor. Modification of the working electrode by introduction of these nanomaterials or combination of two/three of above nanomaterials together and forming a nanocomposite reflected the best results with excellent stability, reproducibility and enhanced sensitivity. Highly attractive electrochemical properties and electrocatalytic activity of these elite nanomaterials have facilitated achievement of enhanced signal amplification needed for the construction of ultrasensitive electrochemical affinity biosensors for detection of glucose, cholesterol, Escherichia coli, influenza virus, cancer, human papillomavirus, dopamine, glutamic acid, IgG, IgE, uric acid, ascorbic acid, acetlycholine, cortisol, cytosome, sequence specific DNA and amino acids. Recent researches for bedside biosensors are also discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Label-free silicon photonic biosensor system with integrated detector array

    Science.gov (United States)

    Yan, Rongjin; Mestas, Santano P.; Yuan, Guangwei; Safaisini, Rashid; Dandy, David S.

    2010-01-01

    An integrated, inexpensive, label-free photonic waveguide biosensor system with multi-analyte capability has been implemented on a silicon photonics integrated circuit from a commercial CMOS line and tested with nanofilms. The local evanescent array coupled (LEAC) biosensor is based on a new physical phenomenon that is fundamentally different from the mechanisms of other evanescent field sensors. Increased local refractive index at the waveguide’s upper surface due to the formation of a biological nanofilm causes local modulation of the evanescent field coupled into an array of photodetectors buried under the waveguide. The planar optical waveguide biosensor system exhibits sensitivity of 20%/nm photocurrent modulation in response to adsorbed bovine serum albumin (BSA) layers less than 3 nm thick. In addition to response to BSA, an experiment with patterned photoresist as well as beam propagation method simulations support the evanescent field shift principle. The sensing mechanism enables the integration of all optical and electronic components for a multi-analyte biosensor system on a chip. PMID:19606292

  11. Fenugreek hydrogel–agarose composite entrapped gold nanoparticles for acetylcholinesterase based biosensor for carbamates detection

    Energy Technology Data Exchange (ETDEWEB)

    Kestwal, Rakesh Mohan; Bagal-Kestwal, Dipali; Chiang, Been-Huang, E-mail: bhchiang@ntu.edu.tw

    2015-07-30

    A biosensor was fabricated to detect pesticides in food samples. Acetylcholinesterase was immobilized in a novel fenugreek hydrogel–agarose matrix with gold nanoparticles. Transparent thin films with superior mechanical strength and stability were obtained with 2% fenugreek hydrogel and 2% agarose. Immobilization of acetylcholinesterase on the membrane resulted in high enzyme retention efficiency (92%) and a significantly prolonged shelf life of the enzyme (half-life, 55 days). Transmission electron microscopy revealed that, gold nanoparticles (10–20 nm in diameter) were uniformly dispersed in the fenugreek hydrogel–agarose–acetylcholinesterase membrane. This immobilized enzyme-gold nanoparticle dip-strip system detected various carbamates, including carbofuran, oxamyl, methomyl, and carbaryl, with limits of detection of 2, 21, 113, and 236 nM (S/N = 3), respectively. Furthermore, the fabricated biosensor exhibited good testing capabilities when used to detect carbamates added to various fruit and vegetable samples. - Highlights: • Acetylcholinesterase (AChE) dip-strip biosensor fabricated to detect carbamates. • AChE entrapped in fenugreek hydrogel–agarose matrix with gold nanoparticles (GNPs). • High enzyme retention efficiency (92%) and shelf life (half-life, 55 days). • Detection limits of carbofuran, oxamyl and methomyl: 2, 21 and 113 nM. • The biosensor had good testing capabilities to detect carbamates in food samples.

  12. Facile and controllable preparation of glucose biosensor based on Prussian blue nanoparticles hybrid composites.

    Science.gov (United States)

    Li, Lei; Sheng, Qinglin; Zheng, Jianbin; Zhang, Hongfang

    2008-11-01

    A glucose biosensor based on polyvinylpyrrolidone (PVP) protected Prussian blue nanoparticles (PBNPs)-polyaniline/multi-walled carbon nanotubes hybrid composites was fabricated by electrochemical method. A novel route for PBNPs preparation was applied in the fabrication with the help of PVP, and from scanning electron microscope images, Prussian blue particles on the electrode were found nanoscaled. The biosensor exhibits fast current response (<6 s) and a linearity in the range from 6.7x10(-6) to 1.9x10(-3) M with a high sensitivity of 6.28 microA mM(-1) and a detection limit of 6x10(-7) M (S/N=3) for the detection of glucose. The apparent activation energy of enzyme-catalyzed reaction and the apparent Michaelis-Menten constant are 23.9 kJ mol(-1) and 1.9 mM respectively, which suggests a high affinity of the enzyme-substrate. This easy and controllable construction method of glucose biosensor combines the characteristics of the components of the hybrid composites, which favors the fast and sensitive detection of glucose with improved analytical capabilities. In addition, the biosensor was examined in human serum samples for glucose determination with a recovery between 95.0 and 104.5%.

  13. Label-free silicon photonic biosensor system with integrated detector array.

    Science.gov (United States)

    Yan, Rongjin; Mestas, Santano P; Yuan, Guangwei; Safaisini, Rashid; Dandy, David S; Lear, Kevin L

    2009-08-07

    An integrated, inexpensive, label-free photonic waveguide biosensor system with multi-analyte capability has been implemented on a silicon photonics integrated circuit from a commercial CMOS line and tested with nanofilms. The local evanescent array coupled (LEAC) biosensor is based on a new physical phenomenon that is fundamentally different from the mechanisms of other evanescent field sensors. Increased local refractive index at the waveguide's upper surface due to the formation of a biological nanofilm causes local modulation of the evanescent field coupled into an array of photodetectors buried under the waveguide. The planar optical waveguide biosensor system exhibits sensitivity of 20%/nm photocurrent modulation in response to adsorbed bovine serum albumin (BSA) layers less than 3 nm thick. In addition to response to BSA, an experiment with patterned photoresist as well as beam propagation method simulations support the evanescent field shift principle. The sensing mechanism enables the integration of all optical and electronic components for a multi-analyte biosensor system on a chip.

  14. A hydrogel biosensor for high selective and sensitive detection of amyloid-beta oligomers.

    Science.gov (United States)

    Sun, Liping; Zhong, Yong; Gui, Jie; Wang, Xianwu; Zhuang, Xiaorong; Weng, Jian

    2018-01-01

    Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive cognitive and memory impairment. It is the most common neurological disease that causes dementia. Soluble amyloid-beta oligomers (AβO) in blood or cerebrospinal fluid (CSF) are the pathogenic biomarker correlated with AD. A simple electrochemical biosensor using graphene oxide/gold nanoparticles (GNPs) hydrogel electrode was developed in this study. Thiolated cellular prion protein (PrP C ) peptide probe was immobilized on GNPs of the hydrogel electrode to construct an AβO biosensor. Electrochemical impedance spectroscopy was utilized for AβO analysis. The specific binding between AβO and PrP C probes on the hydrogel electrode resulted in an increase in the electron-transfer resistance. The biosensor showed high specificity and sensitivity for AβO detection. It could selectively differentiate AβO from amyloid-beta (Aβ) monomers or fibrils. Meanwhile, it was highly sensitive to detect as low as 0.1 pM AβO in artificial CSF or blood plasma. The linear range for AβO detection is from 0.1 pM to 10 nM. This biosensor could be used as a cost-effective tool for early diagnosis of AD due to its high electrochemical performance and bionic structure.

  15. The benzoquinone-mediated electrochemical microbial biosensor for water biotoxicity assay

    International Nuclear Information System (INIS)

    Li, Jiuming; Yu, Yuan; Wang, Yuning; Qian, Jun; Zhi, Jinfang

    2013-01-01

    Graphical abstract: The mediator can participate in microorganism respiration, accept the electrons from respiratory chains, and therefore be reduced by microorganism. The re-oxidization currents of mediators on electrode can reflect the microbial activity, and when respiration is suppressed by toxicants, it can be detected by the resulting change of currents. Unlike other biotoxicity tests, which record the toxic effect after a fixed time for incubation of biocomponents and toxicants, this mediated whole cell biosensor can provide a real-time monitor of the microbial activity during the measurement. -- Abstract: A simple mediated microbial biosensor providing real-time monitoring of water quality and evaluation of biotoxicity was fabricated by entrapping Escherichia coli (E. coli) cells in gelatin on glassy carbon electrode with benzoquinone as the redox mediator. The biotoxicity assay was based on the respiratory activity of E. coli cells estimated by the oxidation current of microbially reduced benzoquinone. The neutrality and lipophilicity rendered benzoquinone better efficiency than ferricyanide in mediated microbial reactions. After the optimization of preparation conditions, the prepared microbial biosensors have measured several common toxicants with different concentrations. In addition, the biotoxicity of binary mixtures of heavy metals and wastewater were investigated. The fabricated biosensor exhibited good repeatability and stability in the biotoxicity measurements

  16. Amperometric Enzyme-Based Biosensors for Application in Food and Beverage Industry

    Science.gov (United States)

    Csöoregi, Elisabeth; Gáspñr, Szilveszter; Niculescu, Mihaela; Mattiasson, Bo; Schuhmann, Wolfgang

    Continuous, sensitive, selective, and reliable monitoring of a large variety of different compounds in various food and beverage samples is of increasing importance to assure a high-quality and tracing of any possible source of contamination of food and beverages. Most of the presently used classical analytical methods are often requiring expensive instrumentation, long analysis times and well-trained staff. Amperometric enzyme-based biosensors on the other hand have emerged in the last decade from basic science to useful tools with very promising application possibilities in food and beverage industry. Amperometric biosensors are in general highly selective, sensitive, relatively cheap, and easy to integrate into continuous analysis systems. A successful application of such sensors for industrial purposes, however, requires a sensor design, which satisfies the specific needs of monitoring the targeted analyte in the particular application, Since each individual application needs different operational conditions and sensor characteristics, it is obvious that biosensors have to be tailored for the particular case. The characteristics of the biosensors are depending on the used biorecognition element (enzyme), nature of signal transducer (electrode material) and the communication between these two elements (electron-transfer pathway).

  17. Biosensor technology for pesticides--a review.

    Science.gov (United States)

    Verma, Neelam; Bhardwaj, Atul

    2015-03-01

    Pesticides, due to their lucrative outcomes, are majorly implicated in agricultural fields for crop production enhancement. Due to their pest removal properties, pesticides of various classes have been designed to persist in the environment over a longer duration after their application to achieve maximum effectiveness. Apart from their recalcitrant structure and agricultural benefits, pesticides also impose acute toxicological effects onto the other various life forms. Their accumulation in the living system may prove to be detrimental if established in higher concentrations. Thus, their prompt and accurate analysis is a crucial matter of concern. Conventional techniques like chromatographic techniques (HPLC, GC, etc.) used for pesticides detection are associated with various limitations like stumpy sensitivity and efficiency, time consumption, laboriousity, requirement of expensive equipments and highly trained technicians, and many more. So there is a need to recruit the methods which can detect these neurotoxic compounds sensitively, selectively, rapidly, and easily in the field. Present work is a brief review of the pesticide effects, their current usage scenario, permissible limits in various food stuffs and 21st century advancements of biosensor technology for pesticide detection. Due to their exceptional performance capabilities, easiness in operation and on-site working, numerous biosensors have been developed for bio-monitoring of various environmental samples for pesticide evaluation immensely throughout the globe. Till date, based on sensing element (enzyme based, antibody based, etc.) and type of detection method used (Electrochemical, optical, and piezoelectric, etc.), a number of biosensors have been developed for pesticide detection. In present communication, authors have summarized 21st century's approaches of biosensor technology for pesticide detection such as enzyme-based biosensors, immunosensors, aptamers, molecularly imprinted polymers, and

  18. Development of electrochemical biosensors with various types of zeolites

    Science.gov (United States)

    Soldatkina, O. V.; Kucherenko, I. S.; Soldatkin, O. O.; Pyeshkova, V. M.; Dudchenko, O. Y.; Akata Kurç, B.; Dzyadevych, S. V.

    2018-03-01

    In the work, different types of zeolites were used for the development of enzyme-based electrochemical biosensors. Zeolites were added to the biorecognition elements of the biosensors and served as additional components of the biomembranes or adsorbents for enzymes. Three types of biosensors (conductometric, amperometric and potentiometric) were studied. The developed biosensors were compared with the similar biosensors without zeolites. The biosensors contained the following enzymes: urease, glucose oxidase, glutamate oxidase, and acetylcholinesterase and were intended for the detection of urea, glucose, glutamate, and acetylcholine, respectively. Construction of the biosensors using the adsorption of enzymes on zeolites has several advantages: simplicity, good reproducibility, quickness, absence of toxic compounds. These benefits are particularly important for the standardization and further mass production of the biosensors. Furthermore, a biosensor for the sucrose determination contained a three-enzyme system (invertase/mutatorase/glucose oxidase), immobilized by a combination of adsorption on silicalite and cross-linking via glutaraldehyde; such combined immobilization demonstrated better results as compared with adsorption or cross-linking separately. The analysis of urea and sucrose concentrations in the real samples was carried out. The results, obtained with biosensors, had high correlation with the results of traditional analytical methods, thus the developed biosensors are promising for practical applications.

  19. Biosensor Architectures for High-Fidelity Reporting of Cellular Signaling

    Science.gov (United States)

    Dushek, Omer; Lellouch, Annemarie C.; Vaux, David J.; Shahrezaei, Vahid

    2014-01-01

    Understanding mechanisms of information processing in cellular signaling networks requires quantitative measurements of protein activities in living cells. Biosensors are molecular probes that have been developed to directly track the activity of specific signaling proteins and their use is revolutionizing our understanding of signal transduction. The use of biosensors relies on the assumption that their activity is linearly proportional to the activity of the signaling protein they have been engineered to track. We use mechanistic mathematical models of common biosensor architectures (single-chain FRET-based biosensors), which include both intramolecular and intermolecular reactions, to study the validity of the linearity assumption. As a result of the classic mechanism of zero-order ultrasensitivity, we find that biosensor activity can be highly nonlinear so that small changes in signaling protein activity can give rise to large changes in biosensor activity and vice versa. This nonlinearity is abolished in architectures that favor the formation of biosensor oligomers, but oligomeric biosensors produce complicated FRET states. Based on this finding, we show that high-fidelity reporting is possible when a single-chain intermolecular biosensor is used that cannot undergo intramolecular reactions and is restricted to forming dimers. We provide phase diagrams that compare various trade-offs, including observer effects, which further highlight the utility of biosensor architectures that favor intermolecular over intramolecular binding. We discuss challenges in calibrating and constructing biosensors and highlight the utility of mathematical models in designing novel probes for cellular signaling. PMID:25099816

  20. Function-based Biosensor for Hazardous Waste Toxin Detection

    Energy Technology Data Exchange (ETDEWEB)

    James J Hickman

    2008-07-09

    There is a need for new types of toxicity sensors in the DOE and other agencies that are based on biological function as the toxins encountered during decontamination or waste remediation may be previously unknown or their effects subtle. Many times the contents of the environmental waste, especially the minor components, have not been fully identified and characterized. New sensors of this type could target unknown toxins that cause death as well as intermediate levels of toxicity that impair function or cause long term impairment that may eventually lead to death. The primary question posed in this grant was to create an electronically coupled neuronal cellular circuit to be used as sensor elements for a hybrid non-biological/biological toxin sensor system. A sensor based on the electrical signals transmitted between two mammalian neurons would allow the marriage of advances in solid state electronics with a functioning biological system to develop a new type of biosensor. Sensors of this type would be a unique addition to the field of sensor technology but would also be complementary to existing sensor technology that depends on knowledge of what is to be detected beforehand. We integrated physics, electronics, surface chemistry, biotechnology, and fundamental neuroscience in the development of this biosensor. Methods were developed to create artificial surfaces that enabled the patterning of discrete cells, and networks of cells, in culture; the networks were then aligned with transducers. The transducers were designed to measure electromagnetic fields (EMF) at low field strength. We have achieved all of the primary goals of the project. We can now pattern neurons routinely in our labs as well as align them with transducers. We have also shown the signals between neurons can be modulated by different biochemicals. In addition, we have made another significant advance where we have repeated the patterning results with adult hippocampal cells. Finally, we

  1. An amperometric hydrogen peroxide biosensor based on Co3O4 nanoparticles and multiwalled carbon nanotube modified glassy carbon electrode

    International Nuclear Information System (INIS)

    Kaçar, Ceren; Dalkiran, Berna; Erden, Pınar Esra; Kiliç, Esma

    2014-01-01

    Highlights: • Hydrogen peroxide biosensor was constructed by combining the advantageous properties of MWCNTs and Co 3 O 4 . • Incorporating Co 3 O 4 nanoparticles into MWCNTs/gelatin film increased the electron transfer. • Co 3 O 4 /MWCNTs/gelatin/HRP/Nafion/GCE showed strong anti-interference ability. • Hydrogen peroxide was successfully determined in disinfector with an average recovery of 100.78 ± 0.89. - Abstract: In this work a new type of hydrogen peroxide biosensor was fabricated based on the immobilization of horseradish peroxidase (HRP) by cross-linking on a glassy carbon electrode (GCE) modified with Co 3 O 4 nanoparticles, multiwall carbon nanotubes (MWCNTs) and gelatin. The introduction of MWCNTs and Co 3 O 4 nanoparticles not only enhanced the surface area of the modified electrode for enzyme immobilization but also facilitated the electron transfer rate, resulting in a high sensitivity of the biosensor. The fabrication process of the sensing surface was characterized by scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Amperometric detection of hydrogen peroxide was investigated by holding the modified electrode at −0.30 V (vs. Ag/AgCl). The biosensor showed optimum response within 5 s at pH 7.0. The optimized biosensor showed linear response range of 7.4 × 10 −7 –1.9 × 10 −5 M with a detection limit of 7.4 × 10 −7 . The applicability of the purposed biosensor was tested by detecting hydrogen peroxide in disinfector samples. The average recovery was calculated as 100.78 ± 0.89

  2. Chitosan coated on the layers' glucose oxidase immobilized on cysteamine/Au electrode for use as glucose biosensor.

    Science.gov (United States)

    Zhang, Yawen; Li, Yunqiu; Wu, Wenjian; Jiang, Yuren; Hu, Biru

    2014-10-15

    A glucose biosensor was developed via direct immobilization of glucose oxidase (GOD) by self-assembled cysteamine monolayer on Au electrode surface followed by coating chitosan on the surface of electrode. In this work, chitosan film was coated on the surface of GOD as a protection film to ensure the stability and biocompatibility of the constructed glucose biosensor. The different application ranges of sensors were fabricated by immobilizing varied layers of GOD. The modified surface film was characterized by a scanning electron microscope (SEM) and the fabrication process of the biosensor was confirmed through electrochemical impedance spectroscopy (EIS) of ferrocyanide. The performance of cyclic voltammetry (CV) in the absence and presence of 25 mM glucose and ferrocenemethanol showed a diffusion-controlled electrode process and reflected the different maximum currents between the different GOD layers. With the developed glucose biosensor, the detection limits of the two linear responses are 49.96 μM and 316.8 μM with the sensitivities of 8.91 μA mM(-1)cm(-2) and 2.93 μA mM(-1)cm(-2), respectively. In addition, good stability (up to 30 days) of the developed biosensor was observed. The advantages of this new method for sensors construction was convenient and different width ranges of detection can be obtained by modified varied layers of GOD. The sensor with two layers of enzyme displayed two current linear responses of glucose. The present work provided a simplicity and novelty method for producing biosensors, which may help design enzyme reactors and biosensors in the future. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Label-free detection of glycoproteins by the lectin biosensor down to attomolar level using gold nanoparticles

    Science.gov (United States)

    Bertok, Tomas; Sediva, Alena; Katrlik, Jaroslav; Gemeiner, Pavol; Mikula, Milan; Nosko, Martin; Tkac, Jan

    2016-01-01

    We present here an ultrasensitive electrochemical biosensor based on a lectin biorecognition capable to detect concentrations of glycoproteins down to attomolar (aM) level by investigation of changes in the charge transfer resistance (Rct) using electrochemical impedance spectroscopy (EIS). On polycrystalline gold modified by an aminoalkanethiol linker layer, gold nanoparticles were attached. A Sambucus nigra agglutinin was covalently immobilised on a mixed self-assembled monolayer formed on gold nanoparticles and finally, the biosensor surface was blocked by poly(vinylalcohol). The lectin biosensor was applied for detection of sialic acid containing glycoproteins fetuin and asialofetuin. Building of a biosensing interface was carefully characterised by a broad range of techniques such as electrochemistry, EIS, atomic force microscopy, scanning electron microscopy and surface plasmon resonance with the best performance of the biosensor achieved by application of HS-(CH2)11-NH2 linker and gold nanoparticles with a diameter of 20 nm. The lectin biosensor responded to an addition of fetuin (8.7% of sialic acid) with sensitivity of (338 ± 11) Ω decade-1 and to asialofetuin (≤ 0.5% of sialic acid) with sensitivity of (109 ± 10) Ω decade-1 with a blank experiment with oxidised asialofetuin (without recognisable sialic acid) revealing sensitivity of detection of (79 ± 13) Ω decade-1. These results suggest the lectin biosensor responded to changes in the glycan amount in a quantitative way with a successful validation by a lectin microarray. Such a biosensor device has a great potential to be employed in early biomedical diagnostics of diseases such as arthritis or cancer, which are connected to aberrant glycosylation of protein biomarkers in biological fluids. PMID:23601864

  4. A label-free and high sensitive aptamer biosensor based on hyperbranched polyester microspheres for thrombin detection

    International Nuclear Information System (INIS)

    Sun, Chong; Han, Qiaorong; Wang, Daoying; Xu, Weimin; Wang, Weijuan; Zhao, Wenbo; Zhou, Min

    2014-01-01

    Highlights: • A label-free thrombin aptamer biosensor applied in whole blood has been developed. • The aptamer biosensor showed a wide detection range and a low detection limit. • The antibiofouling idea utilized for biosensor is significant for diagnostics. - Abstract: In this paper, we have synthesized hyperbranched polyester microspheres with carboxylic acid functional groups (HBPE-CA) and developed a label-free electrochemical aptamer biosensor using thrombin-binding aptamer (TBA) as receptor for the measurement of thrombin in whole blood. The indium tin oxide (ITO) electrode surface modified with HBPE-CA microspheres was grafted with TBA, which has excellent binding affinity and selectivity for thrombin. Binding of the thrombin at the modified ITO electrode surface greatly restrained access of electrons for a redox probe of [Fe(CN) 6 ] 3−/4− . Moreover, the aptamer biosensor could be used for detection of thrombin in whole blood, a wide detection range (10 fM–100 nM) and a detection limit on the order of 0.90 fM were demonstrated. Control experiments were also carried out by using bull serum albumin (BSA) and lysozyme in the absence of thrombin. The good stability and repeatability of this aptamer biosensor were also proved. We expect that this demonstration will lead to the development of highly sensitive label-free sensors based on aptamer with lower cost than current technology. The integration of the technologies, which include anticoagulant, sensor and nanoscience, will bring significant input to high-performance biosensors relevant to diagnostics and therapy of interest for human health

  5. A label-free and high sensitive aptamer biosensor based on hyperbranched polyester microspheres for thrombin detection

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Chong [Jiangsu Key Laboratory of Biofunctional Materials, Biomedical Functional Materials Collaborative Innovation Center, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023 (China); Institute of Agricultural Products Processing, Jiangsu Academy of Agricultural Sciences, Nanjing 210014 (China); Han, Qiaorong [Jiangsu Key Laboratory of Biofunctional Materials, Biomedical Functional Materials Collaborative Innovation Center, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023 (China); Wang, Daoying; Xu, Weimin [Institute of Agricultural Products Processing, Jiangsu Academy of Agricultural Sciences, Nanjing 210014 (China); Wang, Weijuan [Jiangsu Key Laboratory of Biofunctional Materials, Biomedical Functional Materials Collaborative Innovation Center, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023 (China); Zhao, Wenbo, E-mail: zhaowenbo@njnu.edu.cn [Jiangsu Key Laboratory of Biofunctional Materials, Biomedical Functional Materials Collaborative Innovation Center, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023 (China); Zhou, Min, E-mail: zhouminnju@126.com [Department of Vascular Surgery, the Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008 (China)

    2014-11-19

    Highlights: • A label-free thrombin aptamer biosensor applied in whole blood has been developed. • The aptamer biosensor showed a wide detection range and a low detection limit. • The antibiofouling idea utilized for biosensor is significant for diagnostics. - Abstract: In this paper, we have synthesized hyperbranched polyester microspheres with carboxylic acid functional groups (HBPE-CA) and developed a label-free electrochemical aptamer biosensor using thrombin-binding aptamer (TBA) as receptor for the measurement of thrombin in whole blood. The indium tin oxide (ITO) electrode surface modified with HBPE-CA microspheres was grafted with TBA, which has excellent binding affinity and selectivity for thrombin. Binding of the thrombin at the modified ITO electrode surface greatly restrained access of electrons for a redox probe of [Fe(CN){sub 6}]{sup 3−/4−}. Moreover, the aptamer biosensor could be used for detection of thrombin in whole blood, a wide detection range (10 fM–100 nM) and a detection limit on the order of 0.90 fM were demonstrated. Control experiments were also carried out by using bull serum albumin (BSA) and lysozyme in the absence of thrombin. The good stability and repeatability of this aptamer biosensor were also proved. We expect that this demonstration will lead to the development of highly sensitive label-free sensors based on aptamer with lower cost than current technology. The integration of the technologies, which include anticoagulant, sensor and nanoscience, will bring significant input to high-performance biosensors relevant to diagnostics and therapy of interest for human health.

  6. An SPR biosensor for the detection of microcystins in drinking water

    Czech Academy of Sciences Publication Activity Database

    Herranz, S.; Bocková, Markéta; Marazuela, M. D.; Homola, Jiří; Moreno-Bondi, M. C.

    2010-01-01

    Roč. 398, č. 6 (2010), s. 2625-2634 ISSN 1618-2642 R&D Projects: GA AV ČR KAN200670701; GA MŠk OC09058 Institutional research plan: CEZ:AV0Z20670512 Keywords : Microcystin-LR * Label-free biosensor * Surface plasmon resonance Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 3.841, year: 2010

  7. Surface plasmon resonance biosensor for direct detection of antibody against Epstein-Barr virus

    Czech Academy of Sciences Publication Activity Database

    Vaisocherová, Hana; Mrkvová, Kateřina; Piliarik, Marek; Jinoch, P.; Šteinbachová, M.; Homola, Jiří

    2007-01-01

    Roč. 22, č. 6 (2007), s. 1020-1026 ISSN 0956-5663 R&D Projects: GA ČR GA102/03/0633; GA ČR(CZ) GA303/03/0249 Grant - others:European Commission(XE) QLK4-CT-2002-02323 Institutional research plan: CEZ:AV0Z20670512 Keywords : biosensors * surface plasmon resonance * optical sensors Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 5.061, year: 2007

  8. Use of Fe3O4 Nanoparticles for Enhancement of Biosensor Response to the Herbicide 2,4-Dichlorophenoxyacetic Acid

    OpenAIRE

    Loh, Kee-Shyuan; Lee, Yook Heng; Musa, Ahmad; Salmah, Abdul Aziz; Zamri, Ishak

    2008-01-01

    Magnetic nanoparticles of Fe3O4 were synthesized and characterized using transmission electron microscopy and X-ray diffraction. The Fe3O4 nanoparticles were found to have an average diameter of 5.48 ±1.37 nm. An electrochemical biosensor based on immobilized alkaline phosphatase (ALP) and Fe3O4 nanoparticles was studied. The amperometric biosensor was based on the reaction of ALP with the substrate ascorbic acid 2-phosphate (AA2P). The incorporation of the Fe3O4 nanoparticles together wit...

  9. Spreeta-based biosensor for endocrine disruptors

    NARCIS (Netherlands)

    Marchesini, G.R.; Koopal, K.; Meulenberg, E.; Haasnoot, W.; Irth, H.

    2007-01-01

    The construction and performance of an automated low-cost Spreeta¿-based prototype biosensor system for the detection of endocrine disrupting chemicals (EDCs) is described. The system consists primarily of a Spreeta miniature liquid sensor incorporated into an aluminum flow cell holder, dedicated to

  10. Amperometric biosensors based on conducting nanotubes

    NARCIS (Netherlands)

    Kros, Alexander

    2000-01-01

    This thesis describes a multidisciplinary study towards the development of a glucose biosensor that in the future can be used for in vivo implantations. The research focuses on three major topics, viz. the construction of the glucose sensor, the development of a biocompatible coating and a study of

  11. FIBER OPTIC BIOSENSOR FOR DNA DAMAGE

    Science.gov (United States)

    This paper describes a fiber optic biosensor for the rapid and sensitive detection of radiation-induced or chemically-induced oxidative DNA damage. The assay is based on the hybridization and temperature-induced dissociation (melting curves) of synthetic oligonucleotides. The...

  12. Bioluminescent bacteria: lux genes as environmental biosensors

    OpenAIRE

    Nunes-Halldorson,Vânia da Silva; Duran,Norma Letícia

    2003-01-01

    Bioluminescent bacteria are widespread in natural environments. Over the years, many researchers have been studying the physiology, biochemistry and genetic control of bacterial bioluminescence. These discoveries have revolutionized the area of Environmental Microbiology through the use of luminescent genes as biosensors for environmental studies. This paper will review the chronology of scientific discoveries on bacterial bioluminescence and the current applications of bioluminescence in env...

  13. Microbial Biosensors for Selective Detection of Disaccharides

    Science.gov (United States)

    Seven microbial strains were screened for their ability to detect disaccharides as components of Clark-type oxygen biosensors. Sensors responded to varying degrees to maltose, cellobiose, sucrose, and melibiose, but none responded strongly to lactose. Although microbial sensors are relatively nons...

  14. Methods for using redox liposome biosensors

    Science.gov (United States)

    Cheng, Quan; Stevens, Raymond C.

    2002-01-01

    The present invention provides methods and compositions for detecting the presence of biologically-important analytes by using redox liposome biosensors. In particular, the present invention provides liposome/sol-gel electrodes suitable for the detection of a wide variety of organic molecules, including but not limited to bacterial toxins.

  15. Boar taint detection using parasitoid biosensors

    Science.gov (United States)

    To evaluate the potential for a non-stinging wasp to be used as a biosensor in the pig industry, we trained wasps to 3 individual chemicals associated with boar taint. Training consisted of presenting the odors to hungry wasps while they were feeding on sugar. This associates the chemical with a fo...

  16. Clinical Assessment Applications of Ambulatory Biosensors

    Science.gov (United States)

    Haynes, Stephen N.; Yoshioka, Dawn T.

    2007-01-01

    Ambulatory biosensor assessment includes a diverse set of rapidly developing and increasingly technologically sophisticated strategies to acquire minimally disruptive measures of physiological and motor variables of persons in their natural environments. Numerous studies have measured cardiovascular variables, physical activity, and biochemicals…

  17. Biosensors for Whole-Cell Bacterial Detection

    Science.gov (United States)

    Rushworth, Jo V.; Hirst, Natalie A.; Millner, Paul A.

    2014-01-01

    SUMMARY Bacterial pathogens are important targets for detection and identification in medicine, food safety, public health, and security. Bacterial infection is a common cause of morbidity and mortality worldwide. In spite of the availability of antibiotics, these infections are often misdiagnosed or there is an unacceptable delay in diagnosis. Current methods of bacterial detection rely upon laboratory-based techniques such as cell culture, microscopic analysis, and biochemical assays. These procedures are time-consuming and costly and require specialist equipment and trained users. Portable stand-alone biosensors can facilitate rapid detection and diagnosis at the point of care. Biosensors will be particularly useful where a clear diagnosis informs treatment, in critical illness (e.g., meningitis) or to prevent further disease spread (e.g., in case of food-borne pathogens or sexually transmitted diseases). Detection of bacteria is also becoming increasingly important in antibioterrorism measures (e.g., anthrax detection). In this review, we discuss recent progress in the use of biosensors for the detection of whole bacterial cells for sensitive and earlier identification of bacteria without the need for sample processing. There is a particular focus on electrochemical biosensors, especially impedance-based systems, as these present key advantages in terms of ease of miniaturization, lack of reagents, sensitivity, and low cost. PMID:24982325

  18. Biosensor discovery of thyroxine transport disrupting chemicals

    NARCIS (Netherlands)

    Marchesini, G.R.; Meimaridou, A.; Haasnoot, W.; Meulenberg, E.; Albertus, F.; Mizuguchi, M.; Takeuchi, M.; Irth, H.; Murk, A.J.

    2008-01-01

    Ubiquitous chemicals may interfere with the thyroid system that is essential in the development and physiology of vertebrates. We applied a surface plasmon resonance (SPR) biosensor-based screening method for the fast screening of chemicals with thyroxine (T4) transport disrupting activity. Two

  19. Fiber optic-based regenerable biosensor

    Science.gov (United States)

    Sepaniak, Michael J.; Vo-Dinh, Tuan

    1993-01-01

    A fiber optic-based regenerable biosensor. The biosensor is particularly suitable for use in microscale work in situ. In one embodiment, the biosensor comprises a reaction chamber disposed adjacent the distal end of a waveguide and adapted to receive therein a quantity of a sample containing an analyte. Leading into the chamber is a plurality of capillary conduits suitable for introducing into the chamber antibodies or other reagents suitable for selective interaction with a predetermined analyte. Following such interaction, the contents of the chamber may be subjected to an incident energy signal for developing fluorescence within the chamber that is detectable via the optical fiber and which is representative of the presence, i.e. concentration, of the selected analyte. Regeneration of the biosensor is accomplished by replacement of the reagents and/or the analyte, or a combination of these, at least in part via one or more of the capillary conduits. The capillary conduits extend from their respective terminal ends that are in fluid communication with the chamber, away from the chamber to respective location(s) remote from the chamber thereby permitting in situ location of the chamber and remote manipulation and/or analysis of the activity with the chamber.

  20. Disposable electrochemical DNA biosensor for environmental ...

    Indian Academy of Sciences (India)

    been used due to its rapid, easy handling and cost effective responses for the toxicity assessment in real water ... in the application of DNA as biosensors as it is found ... used as a preclinical safety assessment tool to screen ... out the work.

  1. Nano technologies for Biosensor and Bio chip

    International Nuclear Information System (INIS)

    Kim, I.M.; Park, T.J.; Paskaleva, E.E.; Sun, F.; Seo, J.W.; Mehta, K.K.

    2015-01-01

    The bio sensing devices are characterized by their biological receptors, which have specificity to their corresponding analytes. These analytes are a vast and diverse group of biological molecules, DNAs, proteins (such as antibodies), fatty acids, or entire biological systems, such as pathogenic bacteria, viruses, cancerous cells, or other living organisms. A main challenge in the development of biosensor applications is the efficient recognition of a biological signal in a low signal-to-noise ratio environment, and its transduction into an electrochemical, optical, or other signals. The advent of nano material technology greatly increased the potential for achieving exquisite sensitivity of such devises, due to the innate high surface-to-volume ratio and high reactivity of the nano material. The second major challenge facing the biosensor application, that of sca lability, is addressed by multiplexing and miniaturizing of the biosensor devises into a bio chip. In recent years, biosensor and bio chip technologies have made significant progress by taking advantages of diverse kinds of nano materials that are derived from nano technology

  2. ZnS nanoparticles electrodeposited onto ITO electrode as a platform for fabrication of enzyme-based biosensors of glucose

    International Nuclear Information System (INIS)

    Du, Jian; Yu, Xiuping; Wu, Ying; Di, Junwei

    2013-01-01

    The electrochemical and photoelectrochemical biosensors based on glucose oxidase (GOD) and ZnS nanoparticles modified indium tin oxide (ITO) electrode were investigated. The ZnS nanoparticles were electrodeposited directly on the surface of ITO electrode. The enzyme was immobilized on ZnS/ITO electrode surface by sol–gel method to fabricate glucose biosensor. GOD could electrocatalyze the reduction of dissolved oxygen, which resulted in a great increase of the reduction peak current. The reduction peak current decreased linearly with the addition of glucose, which could be used for glucose detection. Moreover, ZnS nanoparticles deposited on ITO electrode surface showed good photocurrent response under illumination. A photoelectrochemical biosensor for the detection of glucose was also developed by monitoring the decreases in the cathodic peak photocurrent. The results indicated that ZnS nanoparticles deposited on ITO substrate were a good candidate material for the immobilization of enzyme in glucose biosensor construction. - Highlights: ► ZnS nanoparticles were electrodeposited directly on ITO surface. ► The direct electron transfer of GOD immobilized on ZnS surface was obtained. ► The enzyme electrode was used to the determination of glucose in the presence of oxygen. ► The response of photoelectrochemical biosensor towards glucose was more sensitive

  3. ZnS nanoparticles electrodeposited onto ITO electrode as a platform for fabrication of enzyme-based biosensors of glucose

    Energy Technology Data Exchange (ETDEWEB)

    Du, Jian; Yu, Xiuping; Wu, Ying; Di, Junwei, E-mail: djw@suda.edu.cn

    2013-05-01

    The electrochemical and photoelectrochemical biosensors based on glucose oxidase (GOD) and ZnS nanoparticles modified indium tin oxide (ITO) electrode were investigated. The ZnS nanoparticles were electrodeposited directly on the surface of ITO electrode. The enzyme was immobilized on ZnS/ITO electrode surface by sol–gel method to fabricate glucose biosensor. GOD could electrocatalyze the reduction of dissolved oxygen, which resulted in a great increase of the reduction peak current. The reduction peak current decreased linearly with the addition of glucose, which could be used for glucose detection. Moreover, ZnS nanoparticles deposited on ITO electrode surface showed good photocurrent response under illumination. A photoelectrochemical biosensor for the detection of glucose was also developed by monitoring the decreases in the cathodic peak photocurrent. The results indicated that ZnS nanoparticles deposited on ITO substrate were a good candidate material for the immobilization of enzyme in glucose biosensor construction. - Highlights: ► ZnS nanoparticles were electrodeposited directly on ITO surface. ► The direct electron transfer of GOD immobilized on ZnS surface was obtained. ► The enzyme electrode was used to the determination of glucose in the presence of oxygen. ► The response of photoelectrochemical biosensor towards glucose was more sensitive.

  4. Preparation and electrochemical application of rutin biosensor for differential pulse voltammetric determination of NADH in the presence of acetaminophen

    Directory of Open Access Journals (Sweden)

    HAMID R. ZARE

    2010-10-01

    Full Text Available The electrocatalytic behavior of reduced nicotinamide adenine di-nucleotide (NADH was studied at the surface of a rutin biosensor, using various electrochemical methods. According to the results, the rutin biosensor had a strongly electrocatalytic effect on the oxidation of NADH with the overpotential being decreased by about 450 mV as compared to the process at a bare glassy carbon electrode, GCE. This value is significantly greater than the value of 220 mV that was reported for rutin embedded in a lipid-cast film. The kinetic parameters of the electron transfer coefficient, a, and the heterogeneous charge transfer rate constant, kh, for the electrocatalytic oxidation of NADH at the rutin biosensor were estimated. Furthermore, the linear dynamic range; sensitivity and limit of detection for NADH were evaluated using the differential pulse voltammetry method. The advantages of this biosensor for the determination of NADH are excellent catalytic activity and reproducibility, good detection limit and high exchange current density. The rutin biosensor could separate the oxidation peak potentials of NADH and acetaminophen present in the same solution while at a bare GCE, the peak potentials were indistinguishable.

  5. Amperometric biosensor for hydrogen peroxide based on Hemoglobin/DNA/Poly-2,6-pyridinediamine modified gold electrode

    International Nuclear Information System (INIS)

    Tong Zhongqiang; Yuan Ruo; Chai Yaqin; Chen Shihong; Xie Yi

    2007-01-01

    An amperometric biosensor for hydrogen peroxide (H 2 O 2 ) was fabricated based on immobilization of hemoglobin (Hb) on DNA/Poly-2,6-pyridinediamine (PPD) modified Au electrode. PPD thin films were firstly electro-deposited on Au electrode surface which provide a template to attach negatively charged DNA molecules by electrostatic attraction. The adsorbed DNA network provides a good microenvironment for the immobilization of biomolecules and promotes electron transfer between the immobilized Hb and the electrode surface. The fabrication process of the biosensor was characterized by electrochemical impedance spectroscopy. Experimental conditions influencing the biosensor performance such as pH, potential and temperature were assessed and optimized. The proposed biosensor displayed a good electrocatalytic response to the reduction of H 2 O 2 , its linear range is 1.7 μM to 3 mM with a detection limit of 1.0 μM based on the signal-to-noise ratio of 3 (S/N = 3) under the optimized conditions. The Michaelis-Menten constant K m app of Hb immobilized on the electrode surface was found to be 0.8 mM. The biosensor shows high sensitivity and stability. Importantly, this deposition methodology could be further developed for the immobilization of other proteins and biocompounds

  6. Label-free detection of DNA hybridization and single point mutations in a nano-gap biosensor

    International Nuclear Information System (INIS)

    Zaffino, R L; Mir, M; Samitier, J

    2014-01-01

    We describe a conductance-based biosensor that exploits DNA-mediated long-range electron transport for the label-free and direct electrical detection of DNA hybridization. This biosensor platform comprises an array of vertical nano-gap biosensors made of gold and fabricated through standard photolithography combined with focused ion beam lithography. The nano-gap walls are covalently modified with short, anti-symmetric thiolated DNA probes, which are terminated by 19 bases complementary to both the ends of a target DNA strand. The nano-gaps are separated by a distance of 50nm, which was adjusted to fit the length of the DNA target plus the DNA probes. The hybridization of the target DNA closes the gap circuit in a switch on/off fashion, in such a way that it is readily detected by an increase in the current after nano-gap closure. The nano-biosensor shows high specificity in the discrimination of base-pair mismatching and does not require signal indicators or enhancing molecules. The design of the biosensor platform is applicable for multiplexed detection in a straightforward manner. The platform is well-suited to mass production, point-of-care diagnostics, and wide-scale DNA analysis applications. (paper)

  7. Construction of novel xanthine biosensor by using polymeric mediator/MWCNT nanocomposite layer for fish freshness detection.

    Science.gov (United States)

    Dervisevic, Muamer; Custiuc, Esma; Çevik, Emre; Şenel, Mehmet

    2015-08-15

    A novel nanocomposite host matrix for enzyme immobilization of xanthine oxidase was developed by incorporating MWCNT in poly(GMA-co-VFc) copolymer film. In the food industry fish is a product with a very low commercial life, and a high variability as well elevated level of xanthine is an important biomarker as a sign of spoilage. The fabricated process was characterized by scanning electron microscopy (SEM), and the electrochemical behaviors of the biosensor were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The prepared enzyme electrodes exhibited maximum response at pH 7.0 and 45°C +0.35 V and reached 95% of steady-state current in about ∼ 4 s and its sensitivity was 16 mAM(-1). Linear ranges (2-28 μM, 28-46 and 46-86 μM), analytical performance and a low detection limit 0.12 μM obtained from the xanthine biosensor gives reliable results in measuring xanthine concentration in the fish meat. All the results indicating that the resulting biosensor exhibited a good response to xanthine that was related to the addition of MWCNT in the polymeric mediator film which played an important role in the biosensor performance. In addition, the biosensor exhibited high good storage stability and satisfactory anti-interference ability. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Graphene–gold nanoparticle composite: Application as a good scaffold for construction of glucose oxidase biosensor

    Energy Technology Data Exchange (ETDEWEB)

    Sabury, Sina [Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Kazemi, Sayed Habib, E-mail: habibkazemi@iasbs.ac.ir [Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731 (Iran, Islamic Republic of); Sharif, Farhad [Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of)

    2015-04-01

    In the present work we report a facile method for fabrication of glucose oxidase immobilized on the partially reduced graphene–gold nanocomposite (PRGO–AuNPs/GOx) as a novel biosensor for determination of glucose concentration. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to study the morphology of PRGO and PRGO–AuNPs. Also, fast Fourier transformation infrared spectroscopy (FTIR) and UV–Vis spectroscopy were used to confirm formation of graphene and graphene–gold composite. Then, the electrochemical behavior of PRGO–AuNPs/GOx modified electrode was studied by cyclic voltammetry (CV). Our electrochemical studies, especially chronoamperometry (CA), showed that the PRGO–AuNPs/GOx modified electrode has excellent electrocatalytic activity towards the glucose. The limit of detection and sensitivity towards glucose were estimated as 0.06 μM and 15.04 mA mM{sup −1}, respectively. - Highlights: • PGRO–AuNPs modified electrode employed as a reliable scaffold for GODx immobilization. • AuNPs prevent stacking PRGO layers, thus improve the electrochemical behavior of biosensor. • GODx electron transfer was improved because of good interaction with PRGO–AuNP scaffold. • PRGO–AuNP/GODx modified biosensor showed excellent sensitivity towards glucose.

  9. Electrodeposition of enzymes-integrated mesoporous composite films by interfacial templating: A paradigm for electrochemical biosensors

    International Nuclear Information System (INIS)

    Wang, Dongming; Tan, Yiwei

    2014-01-01

    The development of nanostructured electrodes for electrochemical biosensors is of significant interest for modern detection, portable devices, and enhanced performance. However, development of such sensors still remains challenging due to the time-consuming, detriment-to-nature, and costly modifications of both electrodes and enzymes. In this work, we report a simple one-step approach to fabricating high-performance, direct electron transfer (DET) based nanoporous enzyme-embedded electrodes by electrodeposition coupled with recent progress in potential-controlled interfacial surfactant assemblies. In contrast to those previously electrodeposited mesoporous materials that are not bioactive, we imparted the biofunctionality to electrodeposited mesoporous thin films by means of the amphiphilic phospholipid templates strongly interacting with enzymes. Thus, phospholipid-templated mesoporous ZnO films covalently inlaid with the pristine enzymes were prepared by simple one-step electrodeposition. We further demonstrate two examples of such hybrid film electrodes embedded with alcohol dehydrogenase (ADH) and glucose oxidase (GOx), which are effectively employed as electrochemical biosensors for amperometric sensing of ethanol and glucose without using any electron relays. The favorable mass transport and large contact surface area provided by nanopores play an important role in improving the performance of these two biosensors, such as excellent sensitivities, low detection limits, and fast response. The matrix mesoporous films acting as effective electronic bridges are responsible for DET between enzyme molecules and metal electrode

  10. Electronics

    Science.gov (United States)

    2001-01-01

    International Acer Incorporated, Hsin Chu, Taiwan Aerospace Industrial Development Corporation, Taichung, Taiwan American Institute of Taiwan, Taipei, Taiwan...Singapore and Malaysia .5 - 4 - The largest market for semiconductor products is the high technology consumer electronics industry that consumes up...Singapore, and Malaysia . A new semiconductor facility costs around $3 billion to build and takes about two years to become operational

  11. Disposable chemical sensors and biosensors made on cellulose paper.

    Science.gov (United States)

    Kim, Joo-Hyung; Mun, Seongcheol; Ko, Hyun-U; Yun, Gyu-Young; Kim, Jaehwan

    2014-03-07

    Most sensors are based on ceramic or semiconducting substrates, which have no flexibility or biocompatibility. Polymer-based sensors have been the subject of much attention due to their ability to collect molecules on their sensing surface with flexibility. Beyond polymer-based sensors, the recent discovery of cellulose as a smart material paved the way to the use of cellulose paper as a potential candidate for mechanical as well as electronic applications such as actuators and sensors. Several different paper-based sensors have been investigated and suggested. In this paper, we review the potential of cellulose materials for paper-based application devices, and suggest their feasibility for chemical and biosensor applications.

  12. Disposable chemical sensors and biosensors made on cellulose paper

    International Nuclear Information System (INIS)

    Kim, Joo-Hyung; Mun, Seongcheol; Ko, Hyun-U; Yun, Gyu-Young; Kim, Jaehwan

    2014-01-01

    Most sensors are based on ceramic or semiconducting substrates, which have no flexibility or biocompatibility. Polymer-based sensors have been the subject of much attention due to their ability to collect molecules on their sensing surface with flexibility. Beyond polymer-based sensors, the recent discovery of cellulose as a smart material paved the way to the use of cellulose paper as a potential candidate for mechanical as well as electronic applications such as actuators and sensors. Several different paper-based sensors have been investigated and suggested. In this paper, we review the potential of cellulose materials for paper-based application devices, and suggest their feasibility for chemical and biosensor applications. (topical review)

  13. Micromachining Lithium Niobate for Rapid Prototyping of Resonant Biosensors

    International Nuclear Information System (INIS)

    Al-Shibaany, Zeyad Yousif Abdoon; Hedley, John; Huo, Dehong; Hu, Zhongxu

    2014-01-01

    Lithium niobate material is widely used in MEMS application due to its piezoelectric properties. This paper presents the micromachining process of lithium niobate to rapid prototype a resonant biosensor design. A high precision CNC machine was used to machine a sample of lithium niobate material at 5 different spindle speeds to find out the best conditions to machine this brittle material. A qualitative visual check of the surface was performed by using scanning electron microscopy, surface roughness was quantitatively investigated using an optical surface profiler and Raman spectroscopy to check the strain of the surface. Results show that the surface quality of the lithium niobate was significantly affected by the spindle speed with optimum conditions at 70k rpm giving a strained surface with 500 nm rms roughness

  14. Protein-modified nanocrystalline diamond thin films for biosensor applications.

    Science.gov (United States)

    Härtl, Andreas; Schmich, Evelyn; Garrido, Jose A; Hernando, Jorge; Catharino, Silvia C R; Walter, Stefan; Feulner, Peter; Kromka, Alexander; Steinmüller, Doris; Stutzmann, Martin

    2004-10-01

    Diamond exhibits several special properties, for example good biocompatibility and a large electrochemical potential window, that make it particularly suitable for biofunctionalization and biosensing. Here we show that proteins can be attached covalently to nanocrystalline diamond thin films. Moreover, we show that, although the biomolecules are immobilized at the surface, they are still fully functional and active. Hydrogen-terminated nanocrystalline diamond films were modified by using a photochemical process to generate a surface layer of amino groups, to which proteins were covalently attached. We used green fluorescent protein to reveal the successful coupling directly. After functionalization of nanocrystalline diamond electrodes with the enzyme catalase, a direct electron transfer between the enzyme's redox centre and the diamond electrode was detected. Moreover, the modified electrode was found to be sensitive to hydrogen peroxide. Because of its dual role as a substrate for biofunctionalization and as an electrode, nanocrystalline diamond is a very promising candidate for future biosensor applications.

  15. Speciation of chromium using chronoamperometric biosensors based on screen-printed electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Calvo-Pérez, Ana, E-mail: anacp@ubu.es; Domínguez-Renedo, Olga, E-mail: olgado@ubu.es; Alonso-Lomillo, MAsunción, E-mail: malomillo@ubu.es; Arcos-Martínez, MJulia, E-mail: jarcos@ubu.es

    2014-06-23

    Highlights: • Chronoamperometric determination of Cr(III) on tyrosinase based biosensors using SPCEs. • Chronoamperometric determination of Cr(VI) on GOx based biosensors using SPCEs. • High degree of sensitivity and selectivity in the analysis of both chromium species. • Bipotentiostatic chronoamperometric determination of both chromium species in the same sample. - Abstract: Chronoamperometric assays based on tyrosinase and glucose oxidase (GOx) inactivation have been developed for the monitoring of Cr(III) and Cr(VI). Tyrosinase was immobilized by crosslinking on screen-printed carbon electrodes (SPCEs) containing tetrathiafulvalene (TTF) as electron transfer mediator. The tyrosinase/SPC{sub TTF}E response to pyrocatechol is inhibited by Cr(III). This process, that is not affected by Cr(VI), allows the determination of Cr(III) with a capability of detection of 2.0 ± 0.2 μM and a reproducibility of 5.5%. GOx modified screen-printed carbon platinised electrodes (SPC{sub Pt}Es) were developed for the selective determination of Cr(VI) using ferricyanide as redox mediator. The biosensor was able to discriminate two different oxidation states of chromium being able to reject Cr(III) and to detect the toxic species Cr(VI). Chronoamperometric response of the biosensor towards glucose decreases with the presence of Cr(VI), with a capability of detection of 90.5 ± 7.6 nM and a reproducibility of 6.2%. A bipotentiostatic chronoamperometric biosensor was finally developed using a tyrosinase/SPC{sub TTF}E and a GOx/SPC{sub Pt}E connected in array mode for the simultaneous determination of Cr(III) and Cr(VI) in spiked tap water and in waste water from a tannery factory samples.

  16. Speciation of chromium using chronoamperometric biosensors based on screen-printed electrodes

    International Nuclear Information System (INIS)

    Calvo-Pérez, Ana; Domínguez-Renedo, Olga; Alonso-Lomillo, MAsunción; Arcos-Martínez, MJulia

    2014-01-01

    Highlights: • Chronoamperometric determination of Cr(III) on tyrosinase based biosensors using SPCEs. • Chronoamperometric determination of Cr(VI) on GOx based biosensors using SPCEs. • High degree of sensitivity and selectivity in the analysis of both chromium species. • Bipotentiostatic chronoamperometric determination of both chromium species in the same sample. - Abstract: Chronoamperometric assays based on tyrosinase and glucose oxidase (GOx) inactivation have been developed for the monitoring of Cr(III) and Cr(VI). Tyrosinase was immobilized by crosslinking on screen-printed carbon electrodes (SPCEs) containing tetrathiafulvalene (TTF) as electron transfer mediator. The tyrosinase/SPC TTF E response to pyrocatechol is inhibited by Cr(III). This process, that is not affected by Cr(VI), allows the determination of Cr(III) with a capability of detection of 2.0 ± 0.2 μM and a reproducibility of 5.5%. GOx modified screen-printed carbon platinised electrodes (SPC Pt Es) were developed for the selective determination of Cr(VI) using ferricyanide as redox mediator. The biosensor was able to discriminate two different oxidation states of chromium being able to reject Cr(III) and to detect the toxic species Cr(VI). Chronoamperometric response of the biosensor towards glucose decreases with the presence of Cr(VI), with a capability of detection of 90.5 ± 7.6 nM and a reproducibility of 6.2%. A bipotentiostatic chronoamperometric biosensor was finally developed using a tyrosinase/SPC TTF E and a GOx/SPC Pt E connected in array mode for the simultaneous determination of Cr(III) and Cr(VI) in spiked tap water and in waste water from a tannery factory samples

  17. A hydrogel biosensor for high selective and sensitive detection of amyloid-beta oligomers

    Directory of Open Access Journals (Sweden)

    Sun LP

    2018-02-01

    Full Text Available Liping Sun,1 Yong Zhong,1 Jie Gui,1 Xianwu Wang,1 Xiaorong Zhuang,2 Jian Weng1 1Key Laboratory of Biomedical Engineering of Fujian Province, Research Center of Biomedical Engineering of Xiamen, Department of Biomaterials, College of Materials, Xiamen University, 2Department of Neurology, The Affiliated Zhongshan Hospital of Xiamen University, Xiamen, People’s Republic of China Background: Alzheimer’s disease (AD is a neurodegenerative disorder characterized by progressive cognitive and memory impairment. It is the most common neurological disease that causes dementia. Soluble amyloid-beta oligomers (AβO in blood or cerebrospinal fluid (CSF are the pathogenic biomarker correlated with AD. Methods: A simple electrochemical biosensor using graphene oxide/gold nanoparticles (GNPs hydrogel electrode was developed in this study. Thiolated cellular prion protein (PrPC peptide probe was immobilized on GNPs of the hydrogel electrode to construct an AβO biosensor. Electrochemical impedance spectroscopy was utilized for AβO analysis. Results: The specific binding between AβO and PrPC probes on the hydrogel electrode resulted in an increase in the electron-transfer resistance. The biosensor showed high specificity and sensitivity for AβO detection. It could selectively differentiate AβO from amyloid-beta (Aβ monomers or fibrils. Meanwhile, it was highly sensitive to detect as low as 0.1 pM AβO in artificial CSF or blood plasma. The linear range for AβO detection is from 0.1 pM to 10 nM. Conclusion: This biosensor could be used as a cost-effective tool for early diagnosis of AD due to its high electrochemical performance and bionic structure. Keywords: Alzheimer’s disease, amyloid-beta oligomer, graphene, gold nanoparticles, biosensor

  18. Glucose biosensor based on a glassy carbon electrode modified with polythionine and multiwalled carbon nanotubes.

    Directory of Open Access Journals (Sweden)

    Wenwei Tang

    Full Text Available A novel glucose biosensor was fabricated. The first layer of the biosensor was polythionine, which was formed by the electrochemical polymerisation of the thionine monomer on a glassy carbon electrode. The remaining layers were coated with chitosan-MWCNTs, GOx, and the chitosan-PTFE film in sequence. The MWCNTs embedded in FAD were like "conductive wires" connecting FAD with electrode, reduced the distance between them and were propitious to fast direct electron transfer. Combining with good electrical conductivity of PTH and MWCNTs, the current response was enlarged. The sensor was a parallel multi-component reaction system (PMRS and excellent electrocatalytic performance for glucose could be obtained without a mediator. The glucose sensor had a working voltage of -0.42 V, an optimum working temperature of 25°C, an optimum working pH of 7.0, and the best percentage of polytetrafluoroethylene emulsion (PTFE in the outer composite film was 2%. Under the optimised conditions, the biosensor displayed a high sensitivity of 2.80 µA mM(-1 cm(-2 and a low detection limit of 5 µM (S/N = 3, with a response time of less than 15 s and a linear range of 0.04 mM to 2.5 mM. Furthermore, the fabricated biosensor had a good selectivity, reproducibility, and long-term stability, indicating that the novel CTS+PTFE/GOx/MWCNTs/PTH composite is a promising material for immobilization of biomolecules and fabrication of third generation biosensors.

  19. A paper-based nanomodified electrochemical biosensor for ethanol detection in beers

    Energy Technology Data Exchange (ETDEWEB)

    Cinti, Stefano, E-mail: stefano.cinti@uniroma2.it; Basso, Mattia; Moscone, Danila; Arduini, Fabiana, E-mail: fabiana.arduini@uniroma2.it

    2017-04-01

    Herein, we report the first example of a paper-based screen-printed biosensor for the detection of ethanol in beer samples. Common office paper was adopted to fabricate the analytical device. The properties of this paper-based screen-printed electrode (SPE) were investigated by cyclic voltammetry, electrochemical impedance spectroscopy, and scanning electron microscopy, and they were compared with the well-established polyester-based SPEs as well. Paper demonstrated similar properties when compared with polyester, highlighting suitability towards its utilization in sensor development, with the advantages of low cost and simple disposal by incineration. A nanocomposite formed by Carbon Black (CB) and Prussian Blue nanoparticles (PBNPs), namely CB/PBNPs, was utilized as an electrocatalyst to detect the hydrogen peroxide generated by the enzymatic reaction between alcohol oxidase (AOx) and ethanol. After optimizing the analytical parameters, such as pH, enzyme, concentration, and working potential, the developed biosensor allowed a facile quantification of ethanol up to 10 mM (0.058 %{sub vol}), with a sensitivity of 9.13 μA/mM cm{sup 2} (1574 μA/%{sub vol} cm{sup 2}) and a detection limit equal to 0.52 mM (0.003%{sub vol}). These satisfactory performances rendered the realized paper-based biosensor reliable over the analysis of ethanol contained in four different types of beers, including Pilsner, Weiss, Lager, and alcohol-free. The proposed manufacturing approach offers an affordable and sustainable tool for food quality control and for the realization of different electrochemical sensors and biosensors as well. - Highlights: • Novel ethanol biosensor fabricated onto office paper. • Enhanced hydrogen peroxide detection using Carbon black/Prussian blue nanoparticles. • Only 100 μL required to perform measurements. • Paper-based electrochemical device coupled with a portable potentiostat. • Rapid quantification of ethanol in beer samples.

  20. A paper-based nanomodified electrochemical biosensor for ethanol detection in beers

    International Nuclear Information System (INIS)

    Cinti, Stefano; Basso, Mattia; Moscone, Danila; Arduini, Fabiana

    2017-01-01

    Herein, we report the first example of a paper-based screen-printed biosensor for the detection of ethanol in beer samples. Common office paper was adopted to fabricate the analytical device. The properties of this paper-based screen-printed electrode (SPE) were investigated by cyclic voltammetry, electrochemical impedance spectroscopy, and scanning electron microscopy, and they were compared with the well-established polyester-based SPEs as well. Paper demonstrated similar properties when compared with polyester, highlighting suitability towards its utilization in sensor development, with the advantages of low cost and simple disposal by incineration. A nanocomposite formed by Carbon Black (CB) and Prussian Blue nanoparticles (PBNPs), namely CB/PBNPs, was utilized as an electrocatalyst to detect the hydrogen peroxide generated by the enzymatic reaction between alcohol oxidase (AOx) and ethanol. After optimizing the analytical parameters, such as pH, enzyme, concentration, and working potential, the developed biosensor allowed a facile quantification of ethanol up to 10 mM (0.058 %_v_o_l), with a sensitivity of 9.13 μA/mM cm"2 (1574 μA/%_v_o_l cm"2) and a detection limit equal to 0.52 mM (0.003%_v_o_l). These satisfactory performances rendered the realized paper-based biosensor reliable over the analysis of ethanol contained in four different types of beers, including Pilsner, Weiss, Lager, and alcohol-free. The proposed manufacturing approach offers an affordable and sustainable tool for food quality control and for the realization of different electrochemical sensors and biosensors as well. - Highlights: • Novel ethanol biosensor fabricated onto office paper. • Enhanced hydrogen peroxide detection using Carbon black/Prussian blue nanoparticles. • Only 100 μL required to perform measurements. • Paper-based electrochemical device coupled with a portable potentiostat. • Rapid quantification of ethanol in beer samples.

  1. Disposable L-lactate biosensor based on a screen-printed carbon electrode enhanced by graphene

    Science.gov (United States)

    Tu, Dandan; He, Yu; Rong, Yuanzhen; Wang, You; Li, Guang

    2016-04-01

    In this work, an amperometric L-lactate biosensor based on a graphene-modified screen-printed carbon electrode (SPCE) was constructed. First, the electrocatalytic performance of the SPCE modified with graphene by a one-step electrodeposition process (OerGO/SPCE) was investigated. The cyclic voltammogram of OerGO/SPCE, which showed a well-defined redox peak, had a smaller peak potential separation than that of SPCE, revealing the improvement in electron transfer speed brought about by modifying with graphene. Next, lactate oxidase and potassium ferricyanide were dropped on the OerGO/SPCE to construct a graphene-modified L-lactate biosensor (LOD/K3[Fe(CN)6]/OerGO/SPCE). The proposed biosensor, with a detection limit of 60 μM, had a high sensitivity (42.42 μA mM-1 cm-2) when working at a low working potential (0.15 V). The linear range was 0.5 mM-15 mM, covering the detecting range of L-lactate in clinical applications. The L-lactate biosensor had a short response time (10 s) and required only 10 μl of the sample. This L-lactate sensor modified with electrodeposited graphene had a larger sensitivity than that based on the bare SPCE. Thus, our low-cost and disposable L-lactate biosensor enhanced by graphene can perform as an attractive electrochemical device that can be manufactured for point-of-care testing (POCT) devices and be employed in POCT applications.

  2. Disposable L-lactate biosensor based on a screen-printed carbon electrode enhanced by graphene

    International Nuclear Information System (INIS)

    Tu, Dandan; He, Yu; Rong, Yuanzhen; Wang, You; Li, Guang

    2016-01-01

    In this work, an amperometric L-lactate biosensor based on a graphene-modified screen-printed carbon electrode (SPCE) was constructed. First, the electrocatalytic performance of the SPCE modified with graphene by a one-step electrodeposition process (OerGO/SPCE) was investigated. The cyclic voltammogram of OerGO/SPCE, which showed a well-defined redox peak, had a smaller peak potential separation than that of SPCE, revealing the improvement in electron transfer speed brought about by modifying with graphene. Next, lactate oxidase and potassium ferricyanide were dropped on the OerGO/SPCE to construct a graphene-modified L-lactate biosensor (LOD/K 3 [Fe(CN) 6 ]/OerGO/SPCE). The proposed biosensor, with a detection limit of 60 μM, had a high sensitivity (42.42 μA mM −1 cm −2 ) when working at a low working potential (0.15 V). The linear range was 0.5 mM–15 mM, covering the detecting range of L-lactate in clinical applications. The L-lactate biosensor had a short response time (10 s) and required only 10 μl of the sample. This L-lactate sensor modified with electrodeposited graphene had a larger sensitivity than that based on the bare SPCE. Thus, our low-cost and disposable L-lactate biosensor enhanced by graphene can perform as an attractive electrochemical device that can be manufactured for point-of-care testing (POCT) devices and be employed in POCT applications. (paper)

  3. Future of biosensors: a personal view.

    Science.gov (United States)

    Scheller, Frieder W; Yarman, Aysu; Bachmann, Till; Hirsch, Thomas; Kubick, Stefan; Renneberg, Reinhard; Schumacher, Soeren; Wollenberger, Ulla; Teller, Carsten; Bier, Frank F

    2014-01-01

    Biosensors representing the technological counterpart of living senses have found routine application in amperometric enzyme electrodes for decentralized blood glucose measurement, interaction analysis by surface plasmon resonance in drug development, and to some extent DNA chips for expression analysis and enzyme polymorphisms. These technologies have already reached a highly advanced level and need minor improvement at most. The dream of the "100-dollar" personal genome may come true in the next few years provided that the technological hurdles of nanopore technology or of polymerase-based single molecule sequencing can be overcome. Tailor-made recognition elements for biosensors including membrane-bound enzymes and receptors will be prepared by cell-free protein synthesis. As alternatives for biological recognition elements, molecularly imprinted polymers (MIPs) have been created. They have the potential to substitute antibodies in biosensors and biochips for the measurement of low-molecular-weight substances, proteins, viruses, and living cells. They are more stable than proteins and can be produced in large amounts by chemical synthesis. Integration of nanomaterials, especially of graphene, could lead to new miniaturized biosensors with high sensitivity and ultrafast response. In the future individual therapy will include genetic profiling of isoenzymes and polymorphic forms of drug-metabolizing enzymes especially of the cytochrome P450 family. For defining the pharmacokinetics including the clearance of a given genotype enzyme electrodes will be a useful tool. For decentralized online patient control or the integration into everyday "consumables" such as drinking water, foods, hygienic articles, clothing, or for control of air conditioners in buildings and cars and swimming pools, a new generation of "autonomous" biosensors will emerge.

  4. Cytochrome c biosensor for determination of trace levels of cyanide and arsenic compounds

    International Nuclear Information System (INIS)

    Fuku, Xolile; Iftikar, Faiza; Hess, Euodia; Iwuoha, Emmanuel; Baker, Priscilla

    2012-01-01

    Highlights: ► Cytochrome c biosensor for detection of KCN, As 2 O 3 and Fe 2 K (CN) was constructed. ► Detection limits in the range of 4.3–9.1 μM for the analytes were obtained using CV, SWV and EIS. ► The detection limits for the biosensor were significantly lower than current EPA and WHO guidelines. - Abstract: An electrochemical method based on a cytochrome c biosensor was developed, for the detection of selected arsenic and cyanide compounds. Boron doped diamond (BDD) electrode was used as a transducer, onto which cytochrome c was immobilised and used for direct determination of Prussian blue, potassium cyanide and arsenic trioxide. The sensitivity as calculated from cyclic voltammetry (CV) and square wave voltammetry (SWV), for each analyte in phosphate buffer (pH = 7) was found to be in the range of (1.1–4.5) × 10 −8 A μM −1 and the detection limits ranged from 4.3 to 9.1 μM. The biosensor is therefore able to measure significantly lower than current Environmental Protection Agency (EPA) and World Health Organisation (WHO) guidelines, for these types of analytes. The protein binding was monitored as a decrease in biosensor peak currents by SWV and as an increase in biosensor charge transfer resistance by electrochemical impedance spectroscopy (EIS). EIS provided evidence that the electrocatalytic advantage of BDD electrode was not lost upon immobilisation of cytochrome c. The interfacial kinetics of the biosensor was modelled as equivalent electrical circuit based on electrochemical impedance spectroscopy data. UV–vis spectroscopy was used to confirm the binding of the protein in solution by monitoring the intensity of the soret bands and the Q bands. FTIR was used to characterise the protein in the immobilised state and to confirm that the protein was not denatured upon binding to the pre-treated bare BDD electrode. SNFTIR of cyt c immobilised at platinum electrode, was used to study the effect of oxidation state on the surface bond

  5. Preparation, characterization and application of urease nanoparticles for construction of an improved potentiometric urea biosensor.

    Science.gov (United States)

    Jakhar, Seema; Pundir, C S

    2018-02-15

    The nanoparticles (NPs) aggregates of commercial urease from jack beans (Canavalia ensiformis) were prepared by desolvation and glutaraldehyde crosslinking and functionalized by cysteamine dihydrochloride. These enzyme nanoparticles (ENPs) were characterized by transmission electron microscopy (TEM), UV and Fourier transform infrared (FTIR) spectroscopy. The TEM images of urease NPs showed their size in the range, 18-100nm with an average of 51.2nm. The ENPs were more active and stable with a longer shelf life than native enzyme molecules. The ENPs were immobilized onto chitosan (CHIT) activated nitrocellulose (NC) membrane via glutaraldehyde coupling with 32.22% retention of initial activity of free ureaseNPs with a conjugation yield of 1.63mg/cm 2 . This NC membrane was mounted at the lower/sensitive end of the ammonium ion selective electrode (AISE) with O-ring and then electrode was connected to a digital pH meter to construct a potentiometric urea biosensor. The biosensor exhibited optimum response within 10s at pH 5.5and 40°C. The biosensor was employed for measurement of potentiometric determination of urea in sera of apparently healthy and persons suffering from kidney disorders. The biosensor displayed a low detection limit of 1µM/L with a wide working range of 2-80µM/L (0.002-0.08mM) and sensitivity of 23mV/decade. The analytical recovery of added urea in serum was 106.33%. The within and between-batch coefficient of variations (CVs) of present biosensor were 0.18% and 0.32% respectively. There was a good correlation (r = 0.99) between sera urea values obtained by reference method (Enzymic colorimetric kit method) and the present biosensor. The biosensor had negligible interference from Na + ,K + ,NH +4 and Ca 2+ but Mg 2+ ,Cu 2+ and ascorbic acid but had slight interference, which was overcome by specific ion selective electrode. The ENPs bound NC membrane was used maximally 8-9 times per day over a period of 180 days, when stored in 0.01M sodium

  6. Acetylcholinesterase biosensor based on SnO2 nanoparticles-carboxylic graphene-nafion modified electrode for detection of pesticides.

    Science.gov (United States)

    Zhou, Qing; Yang, Long; Wang, Guangcan; Yang, Yun

    2013-11-15

    A sensitive amperometric acetylcholinesterase (AChE) biosensor, based on SnO2 nanoparticles (SnO2 NPs), carboxylic graphene (CGR) and nafion (NF) modified glassy carbon electrode (GCE) for the detection of methyl parathion and carbofuran has been developed. The nanocomposites of SnO2 NPs and CGR was synthesized and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR), respectively. Chitosan (CS) was used to immobilize AChE on SnO2 NPs-CGR-NF/GCE and to improve electronic transmission between AChE and SnO2 NPs-CGR-NF/GCE. NF was used as the protective membrane for the AChE biosensor. The SnO2 NPs-CGR-NF nanocomposites with excellent conductivity, catalysis and biocompatibility offered an extremely hydrophilic surface for AChE adhesion. The AChE biosensor showed favorable affinity to acetylthiocholine chloride (ATCl) and could catalyze the hydrolysis of ATCl with an apparent Michaelis-Menten constant value of 131 μM. The biosensor detected methyl parathion in the linear range from 10(-13) to 10(-10)M and from 10(-10) to 10(-8)M. The biosensor detected carbofuran in the linear range from 10(-12) to 10(-10)M and from 10(-10) to 10(-8)M. The detection limits of methyl parathion and carbofuran were 5 × 10(-14)M and 5 × 10(-13)M, respectively. The biosensor exhibited low applied potential, high sensitivity and acceptable stability, thus providing a promising tool for analysis of pesticides. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Biosensors in the small scale: methods and technology trends.

    Science.gov (United States)

    Senveli, Sukru U; Tigli, Onur

    2013-03-01

    This study presents a review on biosensors with an emphasis on recent developments in the field. A brief history accompanied by a detailed description of the biosensor concepts is followed by rising trends observed in contemporary micro- and nanoscale biosensors. Performance metrics to quantify and compare different detection mechanisms are presented. A comprehensive analysis on various types and subtypes of biosensors are given. The fields of interest within the scope of this review are label-free electrical, mechanical and optical biosensors as well as other emerging and popular technologies. Especially, the latter half of the last decade is reviewed for the types, methods and results of the most prominently researched detection mechanisms. Tables are provided for comparison of various competing technologies in the literature. The conclusion part summarises the noteworthy advantages and disadvantages of all biosensors reviewed in this study. Furthermore, future directions that the micro- and nanoscale biosensing technologies are expected to take are provided along with the immediate outlook.

  8. A general strategy to construct small molecule biosensors in eukaryotes.

    Science.gov (United States)

    Feng, Justin; Jester, Benjamin W; Tinberg, Christine E; Mandell, Daniel J; Antunes, Mauricio S; Chari, Raj; Morey, Kevin J; Rios, Xavier; Medford, June I; Church, George M; Fields, Stanley; Baker, David

    2015-12-29

    Biosensors for small molecules can be used in applications that range from metabolic engineering to orthogonal control of transcription. Here, we produce biosensors based on a ligand-binding domain (LBD) by using a method that, in principle, can be applied to any target molecule. The LBD is fused to either a fluorescent protein or a transcriptional activator and is destabilized by mutation such that the fusion accumulates only in cells containing the target ligand. We illustrate the power of this method by developing biosensors for digoxin and progesterone. Addition of ligand to yeast, mammalian, or plant cells expressing a biosensor activates transcription with a dynamic range of up to ~100-fold. We use the biosensors to improve the biotransformation of pregnenolone to progesterone in yeast and to regulate CRISPR activity in mammalian cells. This work provides a general methodology to develop biosensors for a broad range of molecules in eukaryotes.

  9. Fundamental Design Principles for Transcription-Factor-Based Metabolite Biosensors.

    Science.gov (United States)

    Mannan, Ahmad A; Liu, Di; Zhang, Fuzhong; Oyarzún, Diego A

    2017-10-20

    Metabolite biosensors are central to current efforts toward precision engineering of metabolism. Although most research has focused on building new biosensors, their tunability remains poorly understood and is fundamental for their broad applicability. Here we asked how genetic modifications shape the dose-response curve of biosensors based on metabolite-responsive transcription factors. Using the lac system in Escherichia coli as a model system, we built promoter libraries with variable operator sites that reveal interdependencies between biosensor dynamic range and response threshold. We developed a phenomenological theory to quantify such design constraints in biosensors with various architectures and tunable parameters. Our theory reveals a maximal achievable dynamic range and exposes tunable parameters for orthogonal control of dynamic range and response threshold. Our work sheds light on fundamental limits of synthetic biology designs and provides quantitative guidelines for biosensor design in applications such as dynamic pathway control, strain optimization, and real-time monitoring of metabolism.

  10. Impedimetric biosensors for medical applications current progress and challenges

    CERN Document Server

    Rushworth, Jo V; Goode, Jack A; Pike, Douglas J; Ahmed, Asif; Millner, Paul

    2014-01-01

    In this monograph, the authors discuss the current progress in the medical application of impedimetric biosensors, along with the key challenges in the field. First, a general overview of biosensor development, structure and function is presented, followed by a detailed discussion of impedimetric biosensors and the principles of electrochemical impedance spectroscopy. Next, the current state-of-the art in terms of the science and technology underpinning impedance-based biosensors is reviewed in detail. The layer-by-layer construction of impedimetric sensors is described, including the design of electrodes, their nano-modification, transducer surface functionalization and the attachment of different bioreceptors. The current challenges of translating lab-based biosensor platforms into commercially-available devices that function with real patient samples at the POC are presented; this includes a consideration of systems integration, microfluidics and biosensor regeneration. The final section of this monograph ...

  11. Evaluation of three electronic report processing systems for preparing hydrologic reports of the U.S Geological Survey, Water Resources Division

    Science.gov (United States)

    Stiltner, G.J.

    1990-01-01

    In 1987, the Water Resources Division of the U.S. Geological Survey undertook three pilot projects to evaluate electronic report processing systems as a means to improve the quality and timeliness of reports pertaining to water resources investigations. The three projects selected for study included the use of the following configuration of software and hardware: Ventura Publisher software on an IBM model AT personal computer, PageMaker software on a Macintosh computer, and FrameMaker software on a Sun Microsystems workstation. The following assessment criteria were to be addressed in the pilot studies: The combined use of text, tables, and graphics; analysis of time; ease of learning; compatibility with the existing minicomputer system; and technical limitations. It was considered essential that the camera-ready copy produced be in a format suitable for publication. Visual improvement alone was not a consideration. This report consolidates and summarizes the findings of the electronic report processing pilot projects. Text and table files originating on the existing minicomputer system were successfully transformed to the electronic report processing systems in American Standard Code for Information Interchange (ASCII) format. Graphics prepared using a proprietary graphics software package were transferred to all the electronic report processing software through the use of Computer Graphic Metafiles. Graphics from other sources were entered into the systems by scanning paper images. Comparative analysis of time needed to process text and tables by the electronic report processing systems and by conventional methods indicated that, although more time is invested in creating the original page composition for an electronically processed report , substantial time is saved in producing subsequent reports because the format can be stored and re-used by electronic means as a template. Because of the more compact page layouts, costs of printing the reports were 15% to 25

  12. In Vitro Evaluation of Fluorescence Glucose Biosensor Response

    OpenAIRE

    Aloraefy, Mamdouh; Pfefer, T. Joshua; Ramella-Roman, Jessica C.; Sapsford, Kim E.

    2014-01-01

    Rapid, accurate, and minimally-invasive glucose biosensors based on Förster Resonance Energy Transfer (FRET) for glucose measurement have the potential to enhance diabetes control. However, a standard set of in vitro approaches for evaluating optical glucose biosensor response under controlled conditions would facilitate technological innovation and clinical translation. Towards this end, we have identified key characteristics and response test methods, fabricated FRET-based glucose biosensor...

  13. Highly sensitive uric acid biosensor based on individual zinc oxide micro/nanowires

    International Nuclear Information System (INIS)

    Zhao, Yanguang; Yan, Xiaoqin; Kang, Zhuo; Lin, Pei; Fang, Xiaofei; Lei, Yang; Ma, Siwei; Zhang, Yue

    2013-01-01

    We describe the use of individual zinc oxide (ZnO) micro/nanowires in an electrochemical biosensor for uric acid. The wires were synthesized by chemical vapor deposition and possess uniform morphology and high crystallinity as revealed by scanning electron microscopy, X-ray diffraction, and photoluminescence studies. The enzyme uricase was then immobilized on the surface of the ZnO micro/nanowires by physical adsorption, and this was proven by Raman spectroscopy and fluorescence microscopy. The resulting uric acid biosensor undergoes fast electron transfer between the active site of the enzyme and the surface of the electrode. It displays high sensitivity (89.74 μA cm −2 mM −1 ) and a wide linear analytical range (between 0.1 mM and 0.59 mM concentrations of uric acid). This study also demonstrates the potential of the use of individual ZnO micro/nanowires for the construction of highly sensitive nano-sized biosensors. (author)

  14. Electronic resources of the rare books and valuable editions department of the Central Scientific Library of the V.N. Karazin Kharkiv National University: open access for research

    Directory of Open Access Journals (Sweden)

    І. К. Журавльова

    2014-12-01

    Full Text Available The article describes tasks that electronic collections of rare books fulfill: broad access for readers to rare and valuable editions providing, preservation of ensuring of the original. On the example of the electronic collection of the Central Scientific Library of the V.N. Karazin Kharkiv National University – «eScriptorium: electronic archive of rare books and manuscripts for research and education» the possibility of the full-text resources of the valuable editions using is shown. The principles of creation, structure, chronological frameworks, directions of adding the documents to the archive are represented. The perspectives of the project development are outlined as well as examples of the digital libraries of the European countries and Ukraine are provided, the actual task of preserving the originals of the rare books of the country is raised, the innovative approaches to serving users with electronic resources are considered. The evidences of cooperation of the Central Scientific Library of the V.N. Karazin Kharkiv National University with the largest world digital libraries: World Digital Library and Europeana are provided.

  15. The use of quality benchmarking in assessing web resources for the dermatology virtual branch library of the National electronic Library for Health (NeLH).

    Science.gov (United States)

    Kamel Boulos, M N; Roudsari, A V; Gordon, C; Muir Gray, J A

    2001-01-01

    In 1998, the U.K. National Health Service Information for Health Strategy proposed the implementation of a National electronic Library for Health to provide clinicians, healthcare managers and planners, patients and the public with easy, round the clock access to high quality, up-to-date electronic information on health and healthcare. The Virtual Branch Libraries are among the most important components of the National electronic Library for Health. They aim at creating online knowledge based communities, each concerned with some specific clinical and other health-related topics. This study is about the envisaged Dermatology Virtual Branch Libraries of the National electronic Library for Health. It aims at selecting suitable dermatology Web resources for inclusion in the forthcoming Virtual Branch Libraries after establishing preliminary quality benchmarking rules for this task. Psoriasis, being a common dermatological condition, has been chosen as a starting point. Because quality is a principal concern of the National electronic Library for Health, the study includes a review of the major quality benchmarking systems available today for assessing health-related Web sites. The methodology of developing a quality benchmarking system has been also reviewed. Aided by metasearch Web tools, candidate resources were hand-selected in light of the reviewed benchmarking systems and specific criteria set by the authors. Over 90 professional and patient-oriented Web resources on psoriasis and dermatology in general are suggested for inclusion in the forthcoming Dermatology Virtual Branch Libraries. The idea of an all-in knowledge-hallmarking instrument for the National electronic Library for Health is also proposed based on the reviewed quality benchmarking systems. Skilled, methodical, organized human reviewing, selection and filtering based on well-defined quality appraisal criteria seems likely to be the key ingredient in the envisaged National electronic Library for

  16. Barriers to electronic access and delivery of educational information in resource constrained public schools: a case of Greater Tubatse Municipality

    CSIR Research Space (South Africa)

    Pholotho, T

    2016-05-01

    Full Text Available Information and Communication Technologies (ICTs) are capable of expanding access to quality education, educational resources and provide teachers with new skills. Nevertheless, a majority of rural public schools have limited ICTs, mainly due...

  17. Hydrogen peroxide biosensor based on DNA-Hb modified gold electrode

    International Nuclear Information System (INIS)

    Kafi, A.K.M.; Fan Yin; Shin, Hoon-Kyu; Kwon, Young-Soo

    2006-01-01

    A hydrogen peroxide (H 2 O 2 ) biosensor based on DNA-hemoglobin (Hb) modified electrode is described in this paper. The sensor was designed by DNA and hemoglobin dropletting onto gold electrode surface layer by layer. The sensor based on the direct electron transfer of iron of hemoglobin showed a well electrocatalytic response to the reduction of the H 2 O 2 . This sensor offered an excellent electrochemical response for H 2 O 2 concentration below micromole level with high sensitivity and selectivity and short response time. Experimental conditions influencing the biosensor performance such as, pH, potential were optimized and assessed. The levels of the RSD's ( 2 O 2 was observed from 10 to 120 μM with the detection limit of 0.4 μM (based on the S/N = 3)

  18. Biosensor based on a glassy carbon electrode modified with tyrosinase immobilized on multiwalled carbon nanotubes

    International Nuclear Information System (INIS)

    Ren, J.; Kang, T.F.; Xue, R.; Ge, C.N.; Cheng, S.Y.

    2011-01-01

    We describe a biosensor for phenolic compounds that is based on a glassy carbon electrode modified with tyrosinase immobilized on multiwalled carbon nanotubes (MWNTs). The MWNTs possess excellent inherent electrical conductivity which enhances the electron transfer rate and results in good electrochemical catalytic activity towards the reduction of benzoquinone produced by enzymatic reaction. The biosensor was characterized by cyclic voltammetry, and the experimental conditions were optimized. The cathodic current is linearly related to the concentration of the phenols between 0.4 μM and 10 μM, and the detection limit is 0.2 μM. The method was applied to the determination of phenol in water samples (author)

  19. Designing a highly active soluble PQQ-glucose dehydrogenase for efficient glucose biosensors and biofuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Durand, Fabien [Universite de Bordeaux, Centre de Recherche Paul Pascal (CRPP), UPR 8641, Avenue Albert Schweitzer, 33600 Pessac (France); Stines-Chaumeil, Claire [Universite de Bordeaux, CNRS, Institut de Biochimie et de Genetique Cellulaires, 1 rue Camille Saint Saens, 33077 Bordeaux Cedex (France); Flexer, Victoria [Universite de Bordeaux, Centre de Recherche Paul Pascal (CRPP), UPR 8641, Avenue Albert Schweitzer, 33600 Pessac (France); Andre, Isabelle [Universite de Toulouse, INSA, UPS, INP, LISBP, 135 Avenue de Rangueil, F-31077 Toulouse (France); CNRS, UMR5504, F-31400 Toulouse (France); INRA, UMR 792 Ingenierie des Systemes Biologiques et des Procedes, F-31400 Toulouse (France); Mano, Nicolas, E-mail: mano@crpp-bordeaux.cnrs.fr [Universite de Bordeaux, Centre de Recherche Paul Pascal (CRPP), UPR 8641, Avenue Albert Schweitzer, 33600 Pessac (France)

    2010-11-26

    Research highlights: {yields} A new mutant of PQQ-GDH designed for glucose biosensors application. {yields} First mutant of PQQ-GDH with higher activity for D-glucose than the Wild type. {yields} Position N428 is a key point to increase the enzyme activity. {yields} Molecular modeling shows that the N428 C mutant displays a better interaction for PQQ than the WT. -- Abstract: We report for the first time a soluble PQQ-glucose dehydrogenase that is twice more active than the wild type for glucose oxidation and was obtained by combining site directed mutagenesis, modelling and steady-state kinetics. The observed enhancement is attributed to a better interaction between the cofactor and the enzyme leading to a better electron transfer. Electrochemical experiments also demonstrate the superiority of the new mutant for glucose oxidation and make it a promising enzyme for the development of high-performance glucose biosensors and biofuel cells.

  20. Nanotechnology: A Tool for Improved Performance on Electrochemical Screen-Printed (BioSensors

    Directory of Open Access Journals (Sweden)

    Elena Jubete

    2009-01-01

    Full Text Available Screen-printing technology is a low-cost process, widely used in electronics production, especially in the fabrication of disposable electrodes for (biosensor applications. The pastes used for deposition of the successive layers are based on a polymeric binder with metallic dispersions or graphite, and can also contain functional materials such as cofactors, stabilizers and mediators. More recently metal nanoparticles, nanowires and carbon nanotubes have also been included either in these pastes or as a later stage on the working electrode. This review will summarize the use of nanomaterials to improve the electrochemical sensing capability of screen-printed sensors. It will cover mainly disposable sensors and biosensors for biomedical interest and toxicity monitoring, compiling recent examples where several types of metallic and carbon-based nanostructures are responsible for enhancing the performance of these devices.

  1. Characterization of immobilization methods of antiviral antibodies in serum for electrochemical biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Huy, Tran Quang, E-mail: huytq@nihe.org.vn [National Institute of Hygiene and Epidemiology (NIHE), No1 Yersin St., Hanoi (Viet Nam); International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology (HUST), No1 Dai Co Viet, Hanoi (Viet Nam); Hanh, Nguyen Thi Hong; Van Chung, Pham; Anh, Dang Duc; Nga, Phan Thi [National Institute of Hygiene and Epidemiology (NIHE), No1 Yersin St., Hanoi (Viet Nam); Tuan, Mai Anh, E-mail: tuanma-itims@mail.hut.edu.vn [International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology (HUST), No1 Dai Co Viet, Hanoi (Viet Nam)

    2011-06-01

    In this paper, we describes different methods to immobilize Japanese encephalitis virus (JEV) antibodies in human serum onto the interdigitated surface of a microelectrode sensor for optimizing electrochemical detection: (1) direct covalent binding to the silanized surface, (2) binding to the silanized surface via a cross-linker of glutaraldehyde (GA), (3) binding to glutaraldehyde/silanized surface via goat anti-human IgG polyclonal antibody and (4) binding to glutaraldehyde/silanized surface via protein A (PrA). Field emission scanning electron microscopy, Fourier transform infrared spectrometry, and fluorescence microscopy are used to verify the characteristics of antibodies on the interdigitated surface after the serum antibodies immobilization. The analyzed results indicate that the use of protein A is an effective choice for immobilization and orientation of antibodies in serum for electrochemical biosensors. This study provides an advantageous immobilization method of serum containing antiviral antibodies to develop electrochemical biosensors for preliminary screening of viruses in clinical samples from outbreaks.

  2. Highly sensitive voltammetric biosensor for nitric oxide based on its high affinity with hemoglobin

    International Nuclear Information System (INIS)

    Fan Chunhai; Liu Xinjian; Pang Jiantao; Li Genxi; Scheer, Hugo

    2004-01-01

    Although heme protein-based, amperometric nitric oxide (NO) biosensors have been well documented in previous studies, most have been conducted in anaerobic conditions. Herein we report a novel hemoglobin-based NO biosensor that is not only very sensitive but also usable in air. The heme protein was entrapped in a sodium montmorillonite film, which was immobilized at a pyrolytic graphite electrode surface. Film-entrapped hemoglobin can directly exchange electrons with the electrode, and this process has proven to favor the catalytic reduction of oxygen. In addition, NO induced a cathodic potential shift of the catalytic reduction peak of oxygen. This potential shift was proportional to the logarithm of NO concentration ranging from 4.0 x 10 -11 to 5.0 x 10 -6 mol/L. The detection limit has been estimated to be 20 pM, approximately four orders lower than previously reported amperometric detectors

  3. Electronic Grey Literature in Accelerator Science and Its Allied Subjects : Selected Web Resources for Scientists and Engineers

    CERN Document Server

    Rajendiran, P

    2006-01-01

    Grey literature Web resources in the field of accelerator science and its allied subjects are collected for the scientists and engineers of RRCAT (Raja Ramanna Centre for Advanced Technology). For definition purposes the different types of grey literature are described. The Web resources collected and compiled in this article (with an overview and link for each) specifically focus on technical reports, preprints or e-prints, which meet the main information needs of RRCAT users.

  4. A global benchmark study using affinity-based biosensors

    DEFF Research Database (Denmark)

    Rich, Rebecca L; Papalia, Giuseppe A; Flynn, Peter J

    2009-01-01

    To explore the variability in biosensor studies, 150 participants from 20 countries were given the same protein samples and asked to determine kinetic rate constants for the interaction. We chose a protein system that was amenable to analysis using different biosensor platforms as well as by users...... the remaining panel of participants was 620 pM with a standard deviation of 980 pM. These results demonstrate that when this biosensor assay was designed and executed appropriately, the reported rate constants were consistent, and independent of which protein was immobilized and which biosensor was used....

  5. A Highly Responsive Silicon Nanowire/Amplifier MOSFET Hybrid Biosensor

    Science.gov (United States)

    2015-07-21

    Hybrid Biosensor Jieun Lee1,2, Jaeman Jang1, Bongsik Choi1, Jinsu Yoon1, Jee-Yeon Kim3, Yang-Kyu Choi3, Dong Myong Kim1, Dae Hwan Kim1 & Sung-Jin Choi1...This study demonstrates a hybrid biosensor comprised of a silicon nanowire (SiNW) integrated with an amplifier MOSFET to improve the current response...of field-effect-transistor (FET)-based biosensors . The hybrid biosensor is fabricated using conventional CMOS technology, which has the potential

  6. Stepped piezoresistive microcantilever designs for biosensors

    International Nuclear Information System (INIS)

    Ansari, Mohd Zahid; Cho, Chongdu; Urban, Gerald

    2012-01-01

    The sensitivity of a piezoresistive microcantilever biosensor strongly depends on its ability to convert the surface stress-induced deflections into large resistance change. To improve the sensitivity, we present stepped microcantilever biosensor designs that show significant resistance change compared with commonly used rectangular designs. The cantilever is made of silicon dioxide with a u-shaped silicon piezoresistor. The surface stress-induced deflections, bimorph deflection, fundamental resonant frequency and self-heating properties of the cantilever are studied using the FEM software. The surface stress-induced deflections are compared against the analytical model derived in this work. Results show that stepped designs have better signal-to-noise ratio than the rectangular ones and cantilevers with l/L between 0.5 and 0.75 are better designs for improving sensitivity. (paper)

  7. FET-biosensor for cardiac troponin biomarker

    Directory of Open Access Journals (Sweden)

    Md Arshad Mohd Khairuddin

    2017-01-01

    Full Text Available Acute myocardial infarction or myocardial infarction (MI is a major health problem, due to diminished flow of blood to the heart, leads to higher rates of mortality and morbidity. The most specific markers for cardiac injury are cardiac troponin I (cTnI and cardiac troponin T (cTnT which have been considered as ‘gold standard’. Due to higher specificity, determination of the level of cardiac troponins became a predominant indicator for MI. Currently, field-effect transistor (FET-based biosensors have been main interest to be implemented in portable sensors with the ultimate application in point-of-care testing (POCT. In this paper, we review on the FET-based biosensor based on its principle of operation, integration with nanomaterial, surface functionalization as well as immobilization, and the introduction of additional gate (for ambipolar conduction on the device architecture for the detection of cardiac troponin I (cTnI biomarker.

  8. Biosensors for security and bioterrorism applications

    CERN Document Server

    Nikoleli, Georgia-Paraskevi

    2016-01-01

    This book offers comprehensive coverage of biomarker/biosensor interactions for the rapid detection of weapons of bioterrorism, as well as current research trends and future developments and applications. It will be useful to researchers in this field who are interested in new developments in the early detection of such. The authors have collected very valuable and, in some aspects indispensable experience in the area i.e. in the development and application of portable biosensors for the detection of potential hazards. Most efforts are centered on the development of immunochemical assays including flow-lateral systems and engineered antibodies and their fragments. In addition, new approaches to the detection of enzyme inhibitors, direct enzymatic and microbial detection of metabolites and nutrients are elaborated. Some realized prototypes and concept devices applicable for the further use as a basis for the cooperation programs are also discussed. There is a particular focus on electrochemical and optical det...

  9. Biosensor discovery of thyroxine transport disrupting chemicals

    International Nuclear Information System (INIS)

    Marchesini, Gerardo R.; Meimaridou, Anastasia; Haasnoot, Willem; Meulenberg, Eline; Albertus, Faywell; Mizuguchi, Mineyuki; Takeuchi, Makoto; Irth, Hubertus; Murk, Albertinka J.

    2008-01-01

    Ubiquitous chemicals may interfere with the thyroid system that is essential in the development and physiology of vertebrates. We applied a surface plasmon resonance (SPR) biosensor-based screening method for the fast screening of chemicals with thyroxine (T4) transport disrupting activity. Two inhibition assays using the main thyroid hormone transport proteins, T4 binding globulin (TBG) and transthyretin (TTR), in combination with a T4-coated biosensor chip were optimized and automated for screening chemical libraries. The transport protein-based biosensor assays were rapid, high throughput and bioeffect-related. A library of 62 chemicals including the natural hormones, polychlorinated biphenyls (PCBs), polybrominated diphenylethers (PBDEs) and metabolites, halogenated bisphenol A (BPA), halogenated phenols, pharmaceuticals, pesticides and other potential environmentally relevant chemicals was tested with the two assays. We discovered ten new active compounds with moderate to high affinity for TBG with the TBG assay. Strikingly, the most potent binding was observed with hydroxylated metabolites of the brominated diphenyl ethers (BDEs) BDE 47, BDE 49 and BDE 99, that are commonly found in human plasma. The TTR assay confirmed the activity of previously identified hydroxylated metabolites of PCBs and PBDEs, halogenated BPA and genistein. These results show that the hydroxylated metabolites of the ubiquitous PBDEs not only target the T4 transport at the TTR level, but also, and to a great extent, at the TBG level where most of the T4 in humans is circulating. The optimized SPR biosensor-based transport protein assay is a suitable method for high throughput screening of large libraries for potential thyroid hormone disrupting compounds

  10. Biosensor discovery of thyroxine transport disrupting chemicals.

    Science.gov (United States)

    Marchesini, Gerardo R; Meimaridou, Anastasia; Haasnoot, Willem; Meulenberg, Eline; Albertus, Faywell; Mizuguchi, Mineyuki; Takeuchi, Makoto; Irth, Hubertus; Murk, Albertinka J

    2008-10-01

    Ubiquitous chemicals may interfere with the thyroid system that is essential in the development and physiology of vertebrates. We applied a surface plasmon resonance (SPR) biosensor-based screening method for the fast screening of chemicals with thyroxine (T4) transport disrupting activity. Two inhibition assays using the main thyroid hormone transport proteins, T4 binding globulin (TBG) and transthyretin (TTR), in combination with a T4-coated biosensor chip were optimized and automated for screening chemical libraries. The transport protein-based biosensor assays were rapid, high throughput and bioeffect-related. A library of 62 chemicals including the natural hormones, polychlorinated biphenyls (PCBs), polybrominated diphenylethers (PBDEs) and metabolites, halogenated bisphenol A (BPA), halogenated phenols, pharmaceuticals, pesticides and other potential environmentally relevant chemicals was tested with the two assays. We discovered ten new active compounds with moderate to high affinity for TBG with the TBG assay. Strikingly, the most potent binding was observed with hydroxylated metabolites of the brominated diphenyl ethers (BDEs) BDE 47, BDE 49 and BDE 99, that are commonly found in human plasma. The TTR assay confirmed the activity of previously identified hydroxylated metabolites of PCBs and PBDEs, halogenated BPA and genistein. These results show that the hydroxylated metabolites of the ubiquitous PBDEs not only target the T4 transport at the TTR level, but also, and to a great extent, at the TBG level where most of the T4 in humans is circulating. The optimized SPR biosensor-based transport protein assay is a suitable method for high throughput screening of large libraries for potential thyroid hormone disrupting compounds.

  11. Nanostructured ZnO-based biosensor: DNA immobilization and hybridization

    Directory of Open Access Journals (Sweden)

    Ahmed Mishaal Mohammed

    2017-09-01

    Full Text Available An electrochemical DNA biosensor was successfully fabricated by using (3-aminopropyl triethoxysilane (APTES with zinc oxide (ZnO nanorods synthesized using microwave-assisted chemical bath deposition method on thermally oxidized SiO2 thin films. The structural quality and morphology of the ZnO nanorods were determined by employing scanning electron microscopy (SEM and X-ray diffraction (XRD, which show a hexagonal wurtzite structure with a preferred orientation along the (101 direction. The surface of the SiO2 thin films was chemically modified with ZnO. Label-free detection DNA immobilization and hybridization were performed using potassium hexacyanoferrate with cyclic voltammetry (CV measurements. The capacitance, permittivity, and conductivity profiles of the fabricated sensor clearly indicate DNA immobilization and hybridization. Results show that the capacitance values of bare, ZnO- modified surface immobilization, and target DNA hybridization were 46×10−12F, 47×10−8F, 27μF, and 17μF, respectively, at 1Hz. The permittivity measurement increased from 3.94×103 to 251×103 and 165×103 at the frequency range of approximately 200 to 1Hz for bare and DNA immobilization and hybridization, respectively. The measured conductivity values for the bare, ZnO, immobilized, and hybridization device were 2.4×10−9, 10×10−8, 1.6×10−7, and 1.3×10−7Scm−1, respectively. Keywords: Zinc oxide, Biosensor, Capacitance, Permittivity, Conductivity

  12. Synthesis and characterization of microparticles based on poly-methacrylic acid with glucose oxidase for biosensor applications.

    Science.gov (United States)

    Hervás Pérez, J P; López-Ruiz, B; López-Cabarcos, E

    2016-01-01

    In the line of the applicability of biocompatible monomers pH and temperature dependent, we assayed poly-methacrylic acid (p-MAA) microparticles as immobilization system in the design of enzymatic biosensors. Glucose oxidase was used as enzyme model for the study of microparticles as immobilization matrices and as biological material in the performance of glucose biosensors. The enzyme immobilization method was optimized by investigating the influence of monomer concentration and cross-linker content (N',N'-methylenebisacrylamide), used in the preparation of the microparticles in the response of the biosensors. The kinetics of the polymerization and the effects of the temperature were studied, also the conversion of the polymerization was determinates by a weight method. The structure of the obtained p-MAA microparticles were studied through scanning electron microscopy (SEM) and differential scanning microscopy (DSC). The particle size measurements were performed with a Galai-Cis 1 particle analyzer system. Furthermore, the influence of the swelling behavior of hydrogel matrix as a function of pH and temperature were studied. Analytical properties such as sensitivity, linear range, response time and detection limit were studied for the glucose biosensors. The sensitivity for glucose detection obtained with poly-methacrylic acid (p-MAA) microparticles was 11.98mAM(-1)cm(-2) and 10μM of detection limit. A Nafion® layer was used to eliminate common interferents of the human serum such as uric and ascorbic acids. The biosensors were used to determine glucose in human serum samples with satisfactory results. When stored in a frozen phosphate buffer solution (pH 6.0) at -4°C, the useful lifetime of all biosensors was at least 550 days. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Porous photonic crystal external cavity laser biosensor

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Qinglan [Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Peh, Jessie; Hergenrother, Paul J. [Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Cunningham, Brian T. [Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

    2016-08-15

    We report the design, fabrication, and testing of a photonic crystal (PC) biosensor structure that incorporates a porous high refractive index TiO{sub 2} dielectric film that enables immobilization of capture proteins within an enhanced surface-area volume that spatially overlaps with the regions of resonant electromagnetic fields where biomolecular binding can produce the greatest shifts in photonic crystal resonant wavelength. Despite the nanoscale porosity of the sensor structure, the PC slab exhibits narrowband and high efficiency resonant reflection, enabling the structure to serve as a wavelength-tunable element of an external cavity laser. In the context of sensing small molecule interactions with much larger immobilized proteins, we demonstrate that the porous structure provides 3.7× larger biosensor signals than an equivalent nonporous structure, while the external cavity laser (ECL) detection method provides capability for sensing picometer-scale shifts in the PC resonant wavelength caused by small molecule binding. The porous ECL achieves a record high figure of merit for label-free optical biosensors.

  14. L-arginine biosensors: A comprehensive review

    Directory of Open Access Journals (Sweden)

    Neelam Verma

    2017-12-01

    Full Text Available Arginine has been considered as the most potent nutraceutics discovered ever, due to its powerful healing property, and it's been known to scientists as the Miracle Molecule. Arginine detection in fermented food products is necessary because, high level of arginine in foods forms ethyl carbamate (EC during the fermentation process. Therefore, L-arginine detection in fermented food products is very important as a control measure for quality of fermented foods, food supplements and beverages including wine. In clinical analysis arginine detection is important due to their enormous inherent versatility in various metabolic pathways, topmost in the synthesis of Nitric oxide (NO and tumor growth. A number of methods are being used for arginine detection, but biosensors technique holds prime position due to rapid response, high sensitivity and high specificity. However, there are many problems still to be addressed, including selectivity, real time analysis and interference of urea presence in the sample. In the present review we aim to emphasize the significant role of arginine in human physiology and foods. A small attempt has been made to discuss the various techniques used for development of arginine biosensor and how these techniques affect their performance. The choice of transducers for arginine biosensor ranges from optical, pH sensing, ammonia gas sensing, ammonium ion-selective, conductometric and amperometric electrodes because ammonia is formed as a final product.

  15. An aptamer-based biosensor for colorimetric detection of Escherichia coli O157:H7.

    Directory of Open Access Journals (Sweden)

    Wenhe Wu

    Full Text Available BACKGROUND: An aptamer based biosensor (aptasensor was developed and evaluated for rapid colorimetric detection of Escherichia coli (E. coli O157:H7. METHODOLOGY/PRINCIPAL FINDINGS: The aptasensor was assembled by modifying the truncated lipopolysaccharides (LPS-binding aptamer on the surface of nanoscale polydiacetylene (PDA vesicle using peptide bonding between the carboxyl group of the vesicle and the amine group of the aptamer. Molecular recognition between E. coli O157:H7 and aptamer at the interface of the vesicle lead to blue-red transition of PDA which was readily visible to the naked eyes and could be quantified by colorimetric responses (CR. Confocal laser scanning microscope (CLSM and transmission electron microscopy (TEM was used to confirm the specific interactions between the truncated aptamer and E. coli O157:H7. The aptasensor could detect cellular concentrations in a range of 10(4~ 10(8 colony-forming units (CFU/ml within 2 hours and its specificity was 100% for detection of E. coli O157:H7. Compared with the standard culture method, the correspondent rate was 98.5% for the detection of E. coli O157:H7 on 203 clinical fecal specimens with our aptasensor. CONCLUSIONS: The new aptasensor represents a significant advancement in detection capabilities based on the combination of nucleic acid aptamer with PDA vesicle, and offers a specific and convenient screening method for the detection of pathogenic bacteria. This technic could also be applied in areas from clinical analysis to biological terrorism defense, especially in low-resource settings.

  16. Recent Development of Nano-Materials Used in DNA Biosensors

    Directory of Open Access Journals (Sweden)

    Yibin Ying

    2009-07-01

    Full Text Available As knowledge of the structure and function of nucleic acid molecules has increased, sequence-specific DNA detection has gained increased importance. DNA biosensors based on nucleic acid hybridization have been actively developed because of their specificity, speed, portability, and low cost. Recently, there has been considerable interest in using nano-materials for DNA biosensors. Because of their high surface-to-volume ratios and excellent biological compatibilities, nano-materials could be used to increase the amount of DNA immobilization; moreover, DNA bound to nano-materials can maintain its biological activity. Alternatively, signal amplification by labeling a targeted analyte with nano-materials has also been reported for DNA biosensors in many papers. This review summarizes the applications of various nano-materials for DNA biosensors during past five years. We found that nano-materials of small sizes were advantageous as substrates for DNA attachment or as labels for signal amplification; and use of two or more types of nano-materials in the biosensors could improve their overall quality and to overcome the deficiencies of the individual nano-components. Most current DNA biosensors require the use of polymerase chain reaction (PCR in their protocols. However, further development of nano-materials with smaller size and/or with improved biological and chemical properties would substantially enhance the accuracy, selectivity and sensitivity of DNA biosensors. Thus, DNA biosensors without PCR amplification may become a reality in the foreseeable future.

  17. A global benchmark study using affinity-based biosensors

    NARCIS (Netherlands)

    Rich, Rebecca L.; Papalia, Giusseppe A.; Krishnamoorthy, G.; Beusink, J.B.; Pak, Brian J.; Myszka, David G.; more, more

    2009-01-01

    To explore the variability in biosensor studies, 150 participants from 20 countries were given the same protein samples and asked to determine kinetic rate constants for the interaction. We chose a protein system that was amenable to analysis using different biosensor platforms as well as by users

  18. In vitro evaluation of fluorescence glucose biosensor response.

    Science.gov (United States)

    Aloraefy, Mamdouh; Pfefer, T Joshua; Ramella-Roman, Jessica C; Sapsford, Kim E

    2014-07-08

    Rapid, accurate, and minimally-invasive glucose biosensors based on Förster Resonance Energy Transfer (FRET) for glucose measurement have the potential to enhance diabetes control. However, a standard set of in vitro approaches for evaluating optical glucose biosensor response under controlled conditions would facilitate technological innovation and clinical translation. Towards this end, we have identified key characteristics and response test methods, fabricated FRET-based glucose biosensors, and characterized biosensor performance using these test methods. The biosensors were based on competitive binding between dextran and glucose to concanavalin A and incorporated long-wavelength fluorescence dye pairs. Testing characteristics included spectral response, linearity, sensitivity, limit of detection, kinetic response, reversibility, stability, precision, and accuracy. The biosensor demonstrated a fluorescence change of 45% in the presence of 400 mg/dL glucose, a mean absolute relative difference of less than 11%, a limit of detection of 25 mg/dL, a response time of 15 min, and a decay in fluorescence intensity of 72% over 30 days. The battery of tests presented here for objective, quantitative in vitro evaluation of FRET glucose biosensors performance have the potential to form the basis of future consensus standards. By implementing these test methods for a long-visible-wavelength biosensor, we were able to demonstrate strengths and weaknesses with a new level of thoroughness and rigor.

  19. Silicon-on-Insulator Nanowire Based Optical Waveguide Biosensors

    International Nuclear Information System (INIS)

    Li, Mingyu; Liu, Yong; Chen, Yangqing; He, Jian-Jun

    2016-01-01

    Optical waveguide biosensors based on silicon-on-insulator (SOI) nanowire have been developed for label free molecular detection. This paper reviews our work on the design, fabrication and measurement of SOI nanowire based high-sensitivity biosensors employing Vernier effect. Biosensing experiments using cascaded double-ring sensor and Mach-Zehnder- ring sensor integrated with microfluidic channels are demonstrated (paper)

  20. Biosensors engineered from conditionally stable ligand-binding domains

    Science.gov (United States)

    Church, George M.; Feng, Justin; Mandell, Daniel J.; Baker, David; Fields, Stanley; Jester, Benjamin Ward; Tinberg, Christine Elaine

    2017-09-19

    Disclosed is a biosensor engineered to conditionally respond to the presence of specific small molecules, the biosensors including conditionally stable ligand-binding domains (LBDs) which respond to the presence of specific small molecules, wherein readout of binding is provided by reporter genes or transcription factors (TFs) fused to the LBDs.

  1. In Vitro Evaluation of Fluorescence Glucose Biosensor Response

    Directory of Open Access Journals (Sweden)

    Mamdouh Aloraefy

    2014-07-01

    Full Text Available Rapid, accurate, and minimally-invasive glucose biosensors based on Förster Resonance Energy Transfer (FRET for glucose measurement have the potential to enhance diabetes control. However, a standard set of in vitro approaches for evaluating optical glucose biosensor response under controlled conditions would facilitate technological innovation and clinical translation. Towards this end, we have identified key characteristics and response test methods, fabricated FRET-based glucose biosensors, and characterized biosensor performance using these test methods. The biosensors were based on competitive binding between dextran and glucose to concanavalin A and incorporated long-wavelength fluorescence dye pairs. Testing characteristics included spectral response, linearity, sensitivity, limit of detection, kinetic response, reversibility, stability, precision, and accuracy. The biosensor demonstrated a fluorescence change of 45% in the presence of 400 mg/dL glucose, a mean absolute relative difference of less than 11%, a limit of detection of 25 mg/dL, a response time of 15 min, and a decay in fluorescence intensity of 72% over 30 days. The battery of tests presented here for objective, quantitative in vitro evaluation of FRET glucose biosensors performance have the potential to form the basis of future consensus standards. By implementing these test methods for a long-visible-wavelength biosensor, we were able to demonstrate strengths and weaknesses with a new level of thoroughness and rigor.

  2. Biosensor Urea Berbasis Biopolimer Khitin Sebagai Matriks Immobilisasi

    OpenAIRE

    Nazruddin Nazaruddin

    2007-01-01

    Penelitian tentang biosensor urea menggunakan biopolimer khitin sebagai matriks immobilisasi telah dilakukan. Penelitian ini dilakukan untuk mengetahui kinerja biosensor yang dihasilkan yang meliputi sensitivitas, trayek pengukuran, limit deteksi, waktu respon, koefisien selektifitas, dan waktu hidup. Penelitian meliputi beberapa tahap yaitu pembuatan membran polimer khitin dan immobilisasi enzim urease, pelekatan membran khitin pada elektroda pH, dan pengukuran parameter kinerja elektroda. H...

  3. A biosensor device and a method of manufacturing the same

    NARCIS (Netherlands)

    2017-01-01

    A biosensor device (100) for detecting biological particles, the biosensor device (100) comprising a substrate (102), a regular pattern of pores (104) formed in the substrate (102), and a plurality of sensor active structures (106) each of which being arranged on a surface of a corresponding one of

  4. Translating University Biosensor Research to a High School Laboratory Experience

    Science.gov (United States)

    Heldt, Caryn L.; Bank, Alex; Turpeinen, Dylan; King, Julia A.

    2016-01-01

    The need to increase science, technology, engineering, and mathematics (STEM) graduates is great. To interest more students into STEM degrees, we made our graphene biosensor research portable, inexpensive, and safe to demonstrate technology development to high school students. The students increased their knowledge of biosensors and proteins, and…

  5. A biosensor device and a method of manufacturing the same

    NARCIS (Netherlands)

    2009-01-01

    A biosensor device (100) for detecting biological particles, the biosensor device (100) comprising a substrate (102), a regular pattern of pores (104) formed in the substrate (102), and a plurality of sensor active structures (106) each of which being arranged on a surface of a corresponding one of

  6. A novel biosensor based on the direct electrochemistry of horseradish peroxidase immobilized in the three-dimensional flower-like Bi_2WO_6 microspheres

    International Nuclear Information System (INIS)

    Liu, Hui; Guo, Kai; Duan, Congyue; Chen, Xianjin; Zhu, Zhenfeng

    2016-01-01

    Three-dimensional flower-like Bi_2WO_6 microspheres (3D-Bi_2WO_6 MSs) have been synthesized through a simple hydrothermal method. The morphology and structure of 3D-Bi_2WO_6 MSs were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The 3D-Bi_2WO_6 MSs subsequently were used to immobilize horseradish peroxidase (HRP) and fabricate a mediator-free biosensor for the detection of H_2O_2. Spectroscopic and electrochemical results reveal that 3D-Bi_2WO_6 MSs constitute an excellent immobilization matrix with biocompatibility for enzymes. Meanwhile, due to unique morphology of the flower-like microspheres, the direct electron transfer of HRP is facilitated and the prepared biosensors display good performances for the detection of H_2O_2 with a wide linear range, including two linear sections: 0.5–100 μM (R"2 = 0.9983) and 100–250 μM (R"2 = 0.9981), as well as an extremely low method detection limit of 0.18 μM. - Highlights: • 3D-Bi_2WO_6 microspheres are used to fabricate a mediator-free biosensor firstly. • The biosensor displays a wide linear range of 0.5–250 μM for H_2O_2. • The biosensor exhibits a low detection limit of 0.18 μM for H_2O_2.

  7. A potentiometric biosensor for the detection of notch 3 using functionalized ZnO nanorods.

    Science.gov (United States)

    Ibupoto, Z H; Khun, K; Liu, X; Willander, M

    2014-09-01

    The notch signalling plays a vital and radical role for the activity of cellular proliferation, differentiation and apoptosis. In this study, for the first time a particular biosensor is developed for the detection of notch 3. ZnO nanorods were fabricated on the gold coated glass substrate by hydrothermal method and afterwards were decorated with the gold nanoparticles by electrodepositing technique. Scanning electron microscopy (SEM) has shown the perpendicular to the substrate growth pattern of ZnO nanorods. X-ray diffraction (XRD) studies showed the c-axis oriented growth direction with wurtzite crystal structure of ZnO nanorods. X-ray Photoelectron Spectroscopy (XPS) and energy dispersive X-ray (EDX) techniques have shown the presence of Zn, O and Au atoms in the prepared functional material. Furthermore, the anti-notch 3 was physically adsorbed on the gold nanoparticles functionalized ZnO nanorods. The developed potentiometric immunosensor has shown response to the wide range of notch 3 molecules. The detected range included 1.00 x 10(-5)-1.50 x 10(0 ) μg/mL with a sensitivity of 23.15 ± 0.31 mV/decade. The analytical parameters including reproducibility, stability, and selectivity were also investigated and the observed results indicate the acceptable performance of the notch 3 biosensor. Moreover, the proposed notch 3 biosensor exhibited a fast response time of 10 s.

  8. A heparin-functionalized carbon nanotube-based affinity biosensor for dengue virus.

    Science.gov (United States)

    Wasik, Daniel; Mulchandani, Ashok; Yates, Marylynn V

    2017-05-15

    Dengue virus is an arthropod-borne virus transmitted primarily by Aedes mosquitos and is major cause of disease in tropical and subtropical regions. Colloquially known as Dengue Fever, infection can cause hemorrhagic disorders and death in humans and non-human primates. We report a novel electronic biosensor based on a single-walled carbon nanotube network chemiresistive transducer that is functionalized with heparin for low-cost, label-free, ultra-sensitive, and rapid detection of whole dengue virus (DENV). Heparin, an analog of the heparan sulfate proteoglycans that are receptors for dengue virus during infection of Vero cells and hepatocytes, was used for the first time in a biosensor as a biorecognition element instead of traditional antibody. Detection of DENV in viral culture supernatant has similar sensitivity as the corresponding viral titer in phosphate buffer despite the presence of growth media and Vero cell lysate. The biosensor demonstrated sensitivity within the clinically relevant range for humans and infected Aedes aegypti. It has potential application in clinical diagnosis and can improve point-of-care diagnostics of dengue infection. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Development and surface characterization of a glucose biosensor based on a nanocolumnar ZnO film

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, A., E-mail: adriana.rodrigues@partner.kit.edu [Instituto de Física − UFRGS, P.O. Box 15051, 91501-970 Porto Alegre, RS (Brazil); Castegnaro, M.V. [Instituto de Física − UFRGS, P.O. Box 15051, 91501-970 Porto Alegre, RS (Brazil); Arguello, J.; Alves, M.C.M. [Instituto de Química − UFRGS, P.O. Box 15003, 91501-970 Porto Alegre, RS (Brazil); Morais, J., E-mail: jonder@if.ufrgs.br [Instituto de Física − UFRGS, P.O. Box 15051, 91501-970 Porto Alegre, RS (Brazil)

    2017-04-30

    Highlights: • Glucose biosensor based on self-assembled nanocolumnar ZnO deposited on stainless steel. • XPS applied to investigate the GOx immobilization on the ZnO nanocolumns surface. • Observable chemical shifts on O1s and Zn2p corroborates enzime immobilization. - Abstract: Highly oriented nanostructured ZnO films were grown on the surface of stainless steel plates (ZnO/SS) by chemical bath deposition (CBD). The films consisted of vertically aligned ZnO nanocolumns, ∼1 μm long and ∼80 nm wide, as observed by SEM (scanning electron microscopy) and FIB (focused ion beam). XRD (X-ray diffraction) confirmed the c-axis preferred orientation of the ZnO columns, which were functionalized with the glucose oxidase (GOx) enzyme into a biosensor of glucose. The electrochemical response studied by CV (cyclic voltammetry) proved that the biosensor was capable of detecting glucose from 1.5 up to 16 mM concentration range. XPS (X-ray photoelectron spectroscopy) analysis, excited with synchrotron radiation, probed the atom specific chemical environment at the electrode’s surface and shed some light on the nature of the ZnO-GOx interaction.

  10. Preparing cuprous oxide nanomaterials by electrochemical method for non-enzymatic glucose biosensor

    Science.gov (United States)

    Nguyen, Thu-Thuy; Huy, Bui The; Hwang, Seo-Young; Vuong, Nguyen Minh; Pham, Quoc-Thai; Nghia, Nguyen Ngoc; Kirtland, Aaron; Lee, Yong-Ill

    2018-05-01

    Cuprous oxide (Cu2O) nanostructure has been synthesized using an electrochemical method with a two-electrode system. Cu foils were used as electrodes and NH2(OH) was utilized as the reducing agent. The effects of pH and applied voltages on the morphology of the product were investigated. The morphology and optical properties of Cu2O particles were characterized using scanning electron microscopy, x-ray diffraction, and diffuse reflectance spectra. The synthesized Cu2O nanostructures that formed in the vicinity of the anode at 2 V and pH = 11 showed high uniform distribution, small size, and good electrochemical sensing. These Cu2O nanoparticles were coated on an Indium tin oxide substrate and applied to detect non-enzyme glucose as excellent biosensors. The non-enzyme glucose biosensors exhibited good performance with high response, good selectivity, wide linear detection range, and a low detection limit at 0.4 μM. Synthesized Cu2O nanostructures are potential materials for a non-enzyme glucose biosensor.

  11. Comparison between a Conductometric Biosensor and ELISA in the Evaluation of Johne’s Disease

    Directory of Open Access Journals (Sweden)

    Chika Okafor

    2014-10-01

    Full Text Available Johne’s disease (JD, caused by Mycobacterium avium subspecies paratuberculosis (MAP, is an important gastrointestinal disease of cattle worldwide because of the economic losses encountered in JD-affected herds. These losses include reduction in milk yield in cows, premature culling and reduced carcass weight of culled diseased animals. In the U.S. dairy industry, economic losses from reduced productivity associated with JD are estimated to cost between $200 and $250 million annually. The development of non-laboratory-based assays would support more frequent testing of animals for JD and could improve its control. Conductometric biosensors combine immunomigration technology with electronic signal detection and have been adapted for the detection of IgG antibody against MAP. In the present study, a capture membrane with limited variability in the immunomigration channel and an optimal concentration of the secondary anti-bovine antibody used in a previously developed conductometric biosensor were compared with a commercially available antibody detection ELISA in their evaluation of JD, using samples of serum from cattle whose JD status where unknown. There was a moderate strength of agreement (kappa = 0.41 between the two assays. Findings from this preliminary study support the continued development of conductometric biosensors for use in the diagnosis of JD.

  12. Two-dimensional MoS2: A promising building block for biosensors.

    Science.gov (United States)

    Gan, Xiaorong; Zhao, Huimin; Quan, Xie

    2017-03-15

    Recently, two-dimensional (2D) layered nanomaterials have trigged intensive interest due to the intriguing physicochemical properties that stem from a quantum size effect connected with their ultra-thin structure. In particular, 2D molybdenum disulfide (MoS 2 ), as an emerging class of stable inorganic graphene analogs with intrinsic finite bandgap, would possibly complement or even surpass graphene in electronics and optoelectronics fields. In this review, we first discuss the historical development of ultrathin 2D nanomaterials. Then, we are concerned with 2D MoS 2 including its structure-property relationships, synthesis methods, characterization for the layer thickness, and biosensor applications over the past five years. Thereinto, we are highlighting recent advances in 2D MoS 2 -based biosensors, especially emphasize the preparation of sensing elements, roles of 2D MoS 2 , and assay strategies. Finally, on the basis of the current achievements on 2D MoS 2 and other ultrathin layered nanomaterials, perspectives on the challenges and opportunities for the exploration of 2D MoS 2 -based biosensors are put forward. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Nanostructured Tip-Shaped Biosensors: Application of Six Sigma Approach for Enhanced Manufacturing.

    Science.gov (United States)

    Kahng, Seong-Joong; Kim, Jong-Hoon; Chung, Jae-Hyun

    2016-12-23

    Nanostructured tip-shaped biosensors have drawn attention for biomolecule detection as they are promising for highly sensitive and specific detection of a target analyte. Using a nanostructured tip, the sensitivity is increased to identify individual molecules because of the high aspect ratio structure. Various detection methods, such as electrochemistry, fluorescence microcopy, and Raman spectroscopy, have been attempted to enhance the sensitivity and the specificity. Due to the confined path of electrons, electrochemical measurement using a nanotip enables the detection of single molecules. When an electric field is combined with capillary action and fluid flow, target molecules can be effectively concentrated onto a nanotip surface for detection. To enhance the concentration efficacy, a dendritic nanotip rather than a single tip could be used to detect target analytes, such as nanoparticles, cells, and DNA. However, reproducible fabrication with relation to specific detection remains a challenge due to the instability of a manufacturing method, resulting in inconsistent shape. In this paper, nanostructured biosensors are reviewed with our experimental results using dendritic nanotips for sequence specific detection of DNA. By the aid of the Six Sigma approach, the fabrication yield of dendritic nanotips increases from 20.0% to 86.6%. Using the nanotips, DNA is concentrated and detected in a sequence specific way with the detection limit equivalent to 1000 CFU/mL. The pros and cons of a nanotip biosensor are evaluated in conjunction with future prospects.

  14. Preparation of DNA biosensor application from fuel oil waste by functionalization and characterization of MWCNT

    Directory of Open Access Journals (Sweden)

    Ahmed Mishaal Mohammed

    2017-11-01

    Full Text Available The potential of using a multi-wall carbon nanotube (MWCNT synthesized from a fuel oil waste of power plants has discovered for the first time for DNA biosensors application. The MWCNT surface morphologies were examined by field emission scanning electron microscopy (FE-SEM and atomic force microscopy (AFM. The thickness of the MWCNT was found 203nm and confirmed by FESEM. The electrochemical DNA biosensor was successfully developed using a MWCNT modified on SiO2 thin films. The capacitance measurements were performed to detect the sensitivity of DNA detection. The change in capacitance before and after immobilization of the DNA was measured in the frequency range of 1Hz to 1MHz. The results indicate that bare device exhibited the lowest capacitance value, which was 32.7μF. The capacitance value of the DNA immobilization increase to 52μF. The permittivity and conductivity also were examined to study the effect of the DNA immobilization toward the MWCNT modified surface. This present demonstrated that the MWCNT modified SiO2 a thin film was successfully fabricated for DNA biosensor detection. Keywords: Carbon nanotubes, Sensors, Thin films, Electrochemical DNA

  15. Gold and TiO2 Nanostructure Surfaces for Assembling of Electrochemical Biosensors

    International Nuclear Information System (INIS)

    Curulli, A.; Zane, D.

    2008-01-01

    Devices based on nano materials are emerging as a powerful and general class of ultrasensitive sensors for the direct detection of biological and chemical species. In this work, we report the preparation and the full characterization of nano materials such as gold nano wires and TiO 2 nano structured films to be used for assembling of electrochemical biosensors. Gold nano wires were prepared by electroless deposition within the pores of polycarbonate particle track-etched membranes (PMS). Glucose oxidase was deposited onto the nano wires using self-assembling monolayer as an anchor layer for the enzyme molecules. Finally, cyclic voltammetry was performed for different enzymes to test the applicability of gold nano wires as biosensors. Considering another interesting nano material, the realization of functionalized TiO 2 thin films on Si substrates for the immobilization of enzymes is reported. Glucose oxidase and horseradish peroxidase immobilized onto TiO 2 -based nano structured surfaces exhibited a pair of well-defined and quasi reversible voltammetric peaks. The electron exchange between the enzyme and the electrodes was greatly enhanced in the TiO 2 nano structured environment. The electrocatalytic activity of HRP and GOD embedded in TiO 2 electrodes toward H 2 O 2 and glucose, respectively, may have a potential perspective in the fabrication of third-generation biosensors based on direct electrochemistry of enzymes.

  16. Impedimetric Dengue Biosensor based on Functionalized Graphene Oxide Wrapped Silica Particles

    International Nuclear Information System (INIS)

    Jin, Seon-Ah; Poudyal, Shishir; Marinero, Ernesto E.; Kuhn, Richard J.; Stanciu, Lia A.

    2016-01-01

    Highlights: • 3D graphene oxide based material design. • Fabrication of a label-free dengue DNA and RNA impedimetric biosensor. • Design of a surface-based dengue sensor with good selectivity and detection limit. - Abstract: A composite of 3-Aminopropyltriethoxysilane (APTES) functionalized graphene oxide (APTES-GO) wrapped on SiO 2 particles (SiO 2 @APTES-GO) was prepared via self-assembly. Transmission electron microscopy (TEM) and ATR-Fourier Transform Infrared spectroscopy (ATR-FTIR) confirmed wrapping of the SiO 2 particles by the APTES-GO sheets. An impedimetric biosensor was constructed and used to sensitively detect dengue DNA and dengue RNA via primer hybridization using different oligonucleotide sequences. The results demonstrated that the SiO 2 @APTES-GO electrode material led to enhanced dengue RNA detection sensitivity with selectivity and detection limit (1 femto-Molar), compared to both APTES-GO and APTES-SiO 2 . The three-dimensional structure, higher contact area, electrical properties and the ability for rapid hybridization offered by the SiO 2 @APTES-GO led to the successful design of a dengue biosensor with the lowest detection limit reported to date.

  17. Clinician‐selected Electronic Information Resources do not Guarantee Accuracy in Answering Primary Care Physicians’ Information Needs. A review of: McKibbon, K. Ann, and Douglas B. Fridsma. “Effectiveness of Clinician‐selected Electronic Information Resources for Answering Primary Care Physicians’ Information Needs.” Journal of the American Medical Informatics Association 13.6 (2006: 653‐9.

    Directory of Open Access Journals (Sweden)

    Martha Ingrid Preddie

    2008-03-01

    Full Text Available Objective – To determine if electronic information resources selected by primary care physicians improve their ability to answer simulated clinical questions.Design – An observational study utilizing hour‐long interviews and think‐aloud protocols.Setting – The offices and clinics of primary care physicians in Canada and the United States.Subjects – Twenty‐five primary care physicians of whom 4 were women, 17 were from Canada, 22 were family physicians,and 24 were board certified.Methods – Participants provided responses to 23 multiple‐choice questions. Each physician then chose two questions and looked for the answers utilizing information resources of their own choice. The search processes, chosen resources and search times were noted. These were analyzed along with data on the accuracy of the answers and certainties related to the answer to each clinical question prior to the search.Main results – Twenty‐three physicians sought answers to 46 simulated clinical questions. Utilizing only electronic information resources, physicians spent a mean of 13.0 (SD 5.5 minutes searching for answers to the questions, an average of 7.3(SD 4.0 minutes for the first question and 5.8 (SD 2.2 minutes to answer the second question. On average, 1.8 resources were utilized per question. Resources that summarized information, such as the Cochrane Database of Systematic Reviews, UpToDate and Clinical Evidence, were favored 39.2% of the time, MEDLINE (Ovid and PubMed 35.7%, and Internet resources including Google 22.6%. Almost 50% of the search and retrieval strategies were keyword‐based, while MeSH, subheadings and limiting were used less frequently. On average, before searching physicians answered 10 of 23 (43.5% questions accurately. For questions that were searched using clinician‐selected electronic resources, 18 (39.1% of the 46 answers were accurate before searching, while 19 (42.1% were accurate after searching. The difference of

  18. Disease-Related Detection with Electrochemical Biosensors: A Review

    Directory of Open Access Journals (Sweden)

    Ying Huang

    2017-10-01

    Full Text Available Rapid diagnosis of diseases at their initial stage is critical for effective clinical outcomes and promotes general public health. Classical in vitro diagnostics require centralized laboratories, tedious work and large, expensive devices. In recent years, numerous electrochemical biosensors have been developed and proposed for detection of various diseases based on specific biomarkers taking advantage of their features, including sensitivity, selectivity, low cost and rapid response. This article reviews research trends in disease-related detection with electrochemical biosensors. Focus has been placed on the immobilization mechanism of electrochemical biosensors, and the techniques and materials used for the fabrication of biosensors are introduced in details. Various biomolecules used for different diseases have been listed. Besides, the advances and challenges of using electrochemical biosensors for disease-related applications are discussed.

  19. Introduction to Biosensors From Electric Circuits to Immunosensors

    CERN Document Server

    Yoon, Jeong-Yeol

    2013-01-01

    Introduction to Biosensors: From Electric Circuits to Immunosensors discusses underlying circuitry of sensors for biomedical and biological engineers as well as biomedical sensing modalities for electrical engineers while providing an applications-based approach to the study of biosensors with over 13 extensive, hands-on labs. The material is presented using a building-block approach, beginning with the fundamentals of sensor design and temperature sensors and ending with more complicated biosensors. This book also: Provides electrical engineers with the specific knowledge they need to understand biological sensing modalities Provides biomedical engineers with a solid background in circuits and systems Includes complete coverage of temperature sensors, electrochemical sensors, DNA and immunosensors, piezoelectric sensors and immunosensing in a micofluidic device Introduction to Biosensors: From Electric Circuits to Immunosensors aims to provide an interdisciplinary approach to biosensors that will be apprecia...

  20. Android integrated urea biosensor for public health awareness

    Directory of Open Access Journals (Sweden)

    Pranali P. Naik

    2015-03-01

    Full Text Available Integration of a biosensor with a wireless network on the Android 4.2.1 (Jelly Bean platform has been demonstrated. The present study reports an android integrated user friendly Flow injection analysis-Enzyme thermistor (FIA-ET urea biosensor system. This android-integrated biosensor system will facilitate enhanced consumer health and awareness alongside abridging the gap between the food testing laboratory and the concerned higher authorities. Data received from a flow injection mode urea biosensor has been exploited as an integration point among the analyst, the food consumer and the responsible higher authorities. Using the urea biosensor as an example, an alarm system has also been demonstrated both graphically and through text message on a mobile handset. The presented sensor integrated android system will also facilitate decision making support system in various fields of food quality monitoring and clinical analysis.