WorldWideScience

Sample records for biosensor alarm devices

  1. 30 CFR 77.311 - Alarm devices.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Alarm devices. 77.311 Section 77.311 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY....311 Alarm devices. Thermal dryer systems shall be equipped with both audible and visual alarm...

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

    OpenAIRE

    Dey, D.; Goswami, T.

    2011-01-01

    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 biomedi...

  3. Graphene Electronic Device Based Biosensors and Chemical Sensors

    OpenAIRE

    Jiang, Shan

    2014-01-01

    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...

  4. Graphene-metal interfaces for biosensors devices

    Science.gov (United States)

    Zuppella, Paola; Gerlin, Francesca; Bacco, Davide; Corso, Alain J.; Tessarolo, Enrico; Nardello, Marco; Silvestrini, Simone; Maggini, Michele; Pelizzo, Maria G.

    2015-08-01

    Graphene-metals interfaces are investigated in many subject areas both applicative and speculative. The interest mainly stems from the possibility for CVD synthesis of large area graphene on metals. In this case the metal acts as a catalyst for complete dehydrogenetaion of hydrocarbon precursors that leaves carbon behind at the surface. Such bilayer are also very appealing for surface plasmon resonance devices, since graphene acts both as a protective layer and biorecognition element. Several pairs of graphene-metal interfaces have been studied in terms of SPR performance and physicalchemical properties at the interface. With regard to this last aspect, NEXAFS spectroscopy is a powerful method to study single-, double-, and few- layers graphene and to illustrate any evolution of the electronic states.

  5. Fabrication of polyimide based microfluidic channels for biosensor devices

    DEFF Research Database (Denmark)

    Zulfiqar, Azeem; Pfreundt, Andrea; Svendsen, Winnie Edith;

    2015-01-01

    microfluidics is inevitable. This paper demonstrates a novel technique of fabricating microfluidic devices using polyimide (PI) which fulfills the aforementioned properties criteria. A fabrication process to pattern microfluidic channels, using partially cured PI, has been developed by using a dry etching...... in uniformity of PI is also compared to the most commonly used SU8 polymer, which is a near UV sensitive epoxy resin. The potential applications of PI processing are POC and biosensor devices integrated with microelectronics.......The ever-increasing complexity of the fabrication process of Point-of-care (POC) devices, due to high demand of functional versatility, compact size and ease-of-use, emphasizes the need of multifunctional materials that can be used to simplify this process. Polymers, currently in use...

  6. 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)

  7. 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.

  8. Fabrication of polyimide based microfluidic channels for biosensor devices

    Science.gov (United States)

    Zulfiqar, Azeem; Pfreundt, Andrea; Svendsen, Winnie Edith; Dimaki, Maria

    2015-03-01

    The ever-increasing complexity of the fabrication process of Point-of-care (POC) devices, due to high demand of functional versatility, compact size and ease-of-use, emphasizes the need of multifunctional materials that can be used to simplify this process. Polymers, currently in use for the fabrication of the often needed microfluidic channels, have limitations in terms of their physicochemical properties. Therefore, the use of a multipurpose biocompatible material with better resistance to the chemical, thermal and electrical environment, along with capability of forming closed channel microfluidics is inevitable. This paper demonstrates a novel technique of fabricating microfluidic devices using polyimide (PI) which fulfills the aforementioned properties criteria. A fabrication process to pattern microfluidic channels, using partially cured PI, has been developed by using a dry etching method. The etching parameters are optimized and compared to those used for fully cured PI. Moreover, the formation of closed microfluidic channel on wafer level by bonding two partially cured PI layers or a partially cured PI to glass with high bond strength has been demonstrated. The reproducibility in uniformity of PI is also compared to the most commonly used SU8 polymer, which is a near UV sensitive epoxy resin. The potential applications of PI processing are POC and biosensor devices integrated with microelectronics.

  9. 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

  10. Rapid, Sensitive, and Reusable Detection of Glucose by a Robust Radiofrequency Integrated Passive Device Biosensor Chip

    OpenAIRE

    Nam-Young Kim; Kishor Kumar Adhikari; Rajendra Dhakal; Zorigt Chuluunbaatar; Cong Wang; Eun-Soo Kim

    2015-01-01

    Tremendous demands for sensitive and reliable label-free biosensors have stimulated intensive research into developing miniaturized radiofrequency resonators for a wide range of biomedical applications. Here, we report the development of a robust, reusable radiofrequency resonator based integrated passive device biosensor chip fabricated on a gallium arsenide substrate for the detection of glucose in water-glucose solutions and sera. As a result of the highly concentrated electromagnetic ener...

  11. BIOSENSORS

    Science.gov (United States)

    It has recently been proposed under the International Union of Pure and Applied Chemistry (IUPAC) Commission that biosensors be regarded as a subgroup of chemical sensors in which a biologically based mechanism is used for detection of the analyte. hemical sensors are defined und...

  12. A versatile biosensor device for continuous biomedical monitoring

    NARCIS (Netherlands)

    Rhemrev-Boom, MM; Korf, J; Venema, K; Urban, G; Vadgama, P

    2001-01-01

    Although biosensors are by means suitable for continuous biomedical monitoring, due to fouling and blood clotting, in vivo performance is far from optimal. For this reason, ultrafiltration, microdialysis or open tubular flow is frequently used as interface. To secure quantitative recoveries of the a

  13. A randomized controlled trial comparing the effects of counseling and alarm device on HAART adherence and virologic outcomes.

    Directory of Open Access Journals (Sweden)

    Michael H Chung

    2011-03-01

    Full Text Available BACKGROUND: Behavioral interventions that promote adherence to antiretroviral medications may decrease HIV treatment failure. Antiretroviral treatment programs in sub-Saharan Africa confront increasing financial constraints to provide comprehensive HIV care, which include adherence interventions. This study compared the impact of counseling and use of an alarm device on adherence and biological outcomes in a resource-limited setting. METHODS AND FINDINGS: A randomized controlled, factorial designed trial was conducted in Nairobi, Kenya. Antiretroviral-naïve individuals initiating free highly active antiretroviral therapy (HAART in the form of fixed-dose combination pills (d4T, 3TC, and nevirapine were randomized to one of four arms: counseling (three counseling sessions around HAART initiation, alarm (pocket electronic pill reminder carried for 6 months, counseling plus alarm, and neither counseling nor alarm. Participants were followed for 18 months after HAART initiation. Primary study endpoints included plasma HIV-1 RNA and CD4 count every 6 months, mortality, and adherence measured by monthly pill count. Between May 2006 and September 2008, 400 individuals were enrolled, 362 initiated HAART, and 310 completed follow-up. Participants who received counseling were 29% less likely to have monthly adherence <80% (hazard ratio [HR] = 0.71; 95% confidence interval [CI] 0.49-1.01; p = 0.055 and 59% less likely to experience viral failure (HIV-1 RNA ≥5,000 copies/ml (HR 0.41; 95% CI 0.21-0.81; p = 0.01 compared to those who received no counseling. There was no significant impact of using an alarm on poor adherence (HR 0.93; 95% CI 0.65-1.32; p = 0.7 or viral failure (HR 0.99; 95% CI 0.53-1.84; p = 1.0 compared to those who did not use an alarm. Neither counseling nor alarm was significantly associated with mortality or rate of immune reconstitution. CONCLUSIONS: Intensive early adherence counseling at HAART initiation resulted

  14. Electrochemical biosensors and logic devices based on aptamers

    Institute of Scientific and Technical Information of China (English)

    Zuo Xiaolei; Lin Meihua; Fan Chunhai

    2013-01-01

    Aptamers are molecular recognition elements with high specificity that are selected from deoxyribonucleic acid/ribonucleic acid (DNA/RNA) library.Compared with the traditional protein recognition elements,aptamers have excellent properties such as cost-effective,stable,easy for synthesis and modification.In recent years,electrochemistry plays an important role in biosensor field because of its high sensitivity,high stability,fast response and easy miniaturization.Through the combination of these two technologies and our rational design,we constructed a series of biosensors and biochips that are simple,fast,cheap and miniaturized.Firstly,we designed an adenosine triphosphate (ATP) electrochemical biosensor based on the strand displacement strategy.We can detect as low as 10 nmol/L of ATP both in pure solution and complicated cell lysates.Secondly,we creatively split the aptamers into two fragments and constructed the sandwich assay platform only based on single aptamer sequence.We successfully transferred this design on biochips with multiple micro electrodes (6×6) and accomplished multiplex detection.In the fields of biochips and biocomputers,we designed several DNA logic gates with electric (electrochemical) signal as output which paves a new way for the development of DNA computer.

  15. Fabrication of Optical Devices Based on Printable Photonics Technology and Its Application for Biosensor

    Science.gov (United States)

    Endo, Tatsuro; Okuda, Norimichi; Yanagida, Yasuko; Tanaka, Satoru; Hatsuzawa, Takeshi

    The specific optical characteristics which can be observed nanostructured optical device have great potentials for applying to several applications such as lifescience, optical communications, and data storage. Application of nanostrcutured optical device to industry, we suggest “printable photonics technology” for fabrication of nanostructured optical device based on nanoimprint lithography (NIL). In this study, using printable photonics technology, fabrication of flexible photonic crystal (PC) and its application for biosensor was performed. Using printable photonics technology-based PC for biosensing application, high sensitive detection of protein adsorption (detection limit: 1 pg/ml) could be detected.

  16. A biosensor based on graphene nanoribbon with nanopores: a first-principles devices-design

    Institute of Scientific and Technical Information of China (English)

    Ouyang Fang-Ping; Peng Sheng-Lin; Zhang Hua; Weng Li-Bo; Xu Hui

    2011-01-01

    A biosensor device, built from graphene nanoribbons (GNRs) with nanopores, was designed and studied by firstprinciples quantum transport simulation. We have demonstrated the intrinsic transport properties of the device and the effect of different nucleobases on device properties when they are located in the nanopores of GNRs. It was found that the device's current changes remarkably with the species of nucleobases, which originates from their different chemical compositions and coupling strengths with GNRs. In addition, our first-principles results clearly reveal that the distinguished ability of a device's current depends on the position of the pore to some extent. These results may present a new way to read off the nucleobases sequence of a single-stranded DNA (ssDNA) molecule by such GNRs-based device with designed nanopores

  17. Piezoelectric Mass-Sensing Devices as Biosensors-An Alternative to Optical Biosensors?

    Science.gov (United States)

    Janshoff; Galla; Steinem

    2000-11-17

    In the early days of electronic communication-as a result of the limited number of quartz resonators available-frequency adjustment was accomplished by a pencil mark depositing a foreign mass layer on the crystal. In 1959, Sauerbrey showed that the shift in resonance frequency of thickness-shear-mode resonators is proportional to the deposited mass. This was the starting point for the development of a new generation of piezoelectric mass-sensitive devices. However, it was the development of new powerful oscillator circuits that were capable of operating thickness shear mode resonators in fluids that enabled this technique to be introduced into bioanalytic applications. In the last decade adsorption of biomolecules on functionalized surfaces turned in to one of the paramount applications of piezoelectric transducers. These applications include the study of the interaction of DNA and RNA with complementary strands, specific recognition of protein ligands by immobilized receptors, the detection of virus capsids, bacteria, mammalian cells, and last but not least the development of complete immunosensors. Piezoelectric transducers allow a label-free detection of molecules; they are more than mere mass sensors since the sensor response is also influenced by interfacial phenomena, viscoelastic properties of the adhered biomaterial, surface charges of adsorbed molecules, and surface roughness. These new insights have recently been used to investigate the adhesion of cells, liposomes, and proteins onto surfaces, thus allowing the determination of the morphological changes of cells as a response to pharmacological substances and changes in the water content of biopolymers without employing labor-intense techniques. However, the future will show whether the quartz-crystal microbalance will assert itself against established label-free sensor devices such as surface plasmon resonance spectroscopy and interferometry. PMID:11093194

  18. 视觉报警信号检测工装设计%Designation of Visual Alarm Signals Test Device

    Institute of Scientific and Technical Information of China (English)

    许于春; 陈卓强; 邓潇彬

    2014-01-01

    As the state standard YY 0709 Medical electrical equipment-Part 1-8: General requirements for basic safety and essential performance-Col ateral standard: General requirements, tests and guidance for alarm systems in medical electrical equipment and medical electrical systems was to enforce. It is important to make the test easier and faster. This paper detailed description the designation of visual alarm signals test device.%国家行业标准Y Y 0709-2009《医用电气设备第1-8部分:安全通用要求并列标准:通用要求,医用电气设备和医用电气系统中报警系统的测试和指南》已于2010年12月01日实施,如何让检测工作变得更加简便快捷尤为重要。本文详细介绍了视觉报警信号检测工装的设计。

  19. Biosensors. Biosensoren

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, R.D. (TU Braunschweig (Germany) Gesellschaft fuer Biotechnologische Forschung (GBF), Braunschweig (Germany). Bereich Enzymtechnologie/Naturstoffchemie); Bilitewski, U. (Gesellschaft fuer Biotechnologische Forschung (GBF), Braunschweig (Germany). Abt. Enzymtechnologie)

    1992-08-01

    A biosensor is an analysis device in which a biological component (e.g. enzyme or antibody) is connected with a signal transducer. The signal transducer converts a biochemical primary reaction - or its chemical secondary reaction - into an optical or electrical signal. The most important measuring methods are described: Amperometric, potentiometric and optical biosensors; monomolecular films, flow injection systems and so on. Different applications for biosensors are introduced; e.g. in medicine, bioprocess control, food analysis and environmental protection. (orig.).

  20. A plastic total internal reflection-based photoluminescence device for enzymatic biosensors

    Science.gov (United States)

    Thakkar, Ishan G.

    Growing concerns for quality of water, food and beverages in developing and developed countries drive sizeable markets for mass-producible, low cost devices that can measure the concentration of contaminant chemicals in water, food, and beverages rapidly and accurately. Several fiber-optic enzymatic biosensors have been reported for these applications, but they exhibit very strong presence of scattered excitation light in the signal for sensing, requiring expensive thin-film filters, and their non-planar structure makes them challenging to mass-produce. Several other planar optical waveguide-based biosensors prove to be relatively costly and more fragile due to constituent materials and the techniques involved in their fabrication. So, a plastic total internal reflection (TIR)-based low cost, low scatter, field-portable device for enzymatic biosensors is fabricated and demonstrated. The design concept of the TIR-based photoluminescent enzymatic biosensor device is explained. An analysis of economical materials with appropriate optical and chemical properties is presented. PMMA and PDMS are found to be appropriate due to their high chemical resistance, low cost, high optical transmittance and low auto-fluorescence. The techniques and procedures used for device fabrication are discussed. The device incorporated a PMMA-based optical waveguide core and PDMS-based fluid cell with simple multi-mode fiber-optics using cost-effective fabrication techniques like molding and surface modification. Several techniques of robustly depositing photoluminescent dyes on PMMA core surface are discussed. A pH-sensitive fluorescent dye, fluoresceinamine, and an O2-sensitive phosphorescent dye, Ru(dpp) both are successfully deposited using Si-adhesive gel-based as well as HydroThane-based deposition methods. Two different types of pH-sensors using two different techniques of depositing fluoresceinamine are demonstrated. Also, the effect of concentration of fluoresceinamine-dye molecules

  1. Research of the Warning Alarm Device of Vehicle Rollover%汽车侧翻预警报警装置的研究

    Institute of Scientific and Technical Information of China (English)

    陈启鹏; 熊巧巧; 周成

    2012-01-01

    阐述了汽车侧翻的危害,以及我国汽车侧翻预警装置的研究现状.简述了汽车侧翻预警报警装置的工作原理,提出了一种基于侧向加速度和基于横向载荷转移率为侧翻判断条件的侧翻预警的方法.指出侧向加速度和横向载荷转移率是开发实用汽车侧翻预警报警系统的关键技术,并对汽车侧翻预警报警装置的实用性进行了探讨.%This paper states the damage of vehicle rollover, and the research status of the warning alarm device of vehicle rollover at home. Additionally, it supplely states the warning alarm device of vehicle rollover,which presents a rollover warning method that based on lateral acceleration and lateral load transfer ratio. And finally,it points out lateral acceleration and lateral load transfer ratio are the key technology of exploiting the application vehicle rollover warning alarm system, and discuss the practicability of vehicle rollover warning alarm device.

  2. 21 CFR 870.1025 - Arrhythmia detector and alarm (including ST-segment measurement and alarm).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Arrhythmia detector and alarm (including ST... Diagnostic Devices § 870.1025 Arrhythmia detector and alarm (including ST-segment measurement and alarm). (a) Identification. The arrhythmia detector and alarm device monitors an electrocardiogram and is designed to...

  3. Selective in situ functionalization of biosensors on LOC devices using laminar co-flow.

    Science.gov (United States)

    Parra-Cabrera, C; Sporer, C; Rodriguez-Villareal, I; Rodriguez-Trujillo, R; Homs-Corbera, A; Samitier, J

    2012-10-21

    Many applications involving lab-on-a-chip (LOC) devices are prevented from entering the market because of difficulties to achieve mass production and impart suitable properties allowing long-term storage. To integrate biosensors on these microfluidic chips, one of the main restrictions is the fabrication and stability of the molecular modifications that must be performed on the surfaces of the sensors for a given application. The complexity of the problem increases exponentially when the LOC integrates several of these sensors. Here we present a system based on laminar co-flow to perform an on-chip selective surface bio-functionalization of LOC-integrated sensors. This method has the advantage that the surface modification protocols are performed in situ before analyte detection. This approach reduces the burdens during LOC fabrication, keeping the required reagents stored outside of the detection structure in suitable wet conditions. The proof of concept is demonstrated through an optical characterization followed by electronic detection based on a novel differential impedance measurement setup. The system can be easily scaled to incorporate several sensors with distinct biosensing targets in a single chip.

  4. 一种可控沸腾报警装置的设计与应用%Application and design of a controllable boiling alarm device

    Institute of Scientific and Technical Information of China (English)

    颜桂炀; 郑柳萍; 李传基; 陈文

    2012-01-01

    介绍一种新型可控的沸腾报警装置的设计原理,并结合电磁炉的加热特性,提出了适用于生态瓷壶的可控沸腾报警装置的具体措施.该设计方案结构简单,使用安全,成本低廉,避免了废旧电池对环境的污染.装置在水沸腾后自动切断电磁炉加热电路,既消除了安全隐患,又节省了能源,可适用于非金属电磁炉加热容器,具有很高的实用性.%This paper introduces the design principle of a novel controllable boiling alarm device.Combined with the heat characteristic of induction cooker,it proposes the detail measures on controllable boiling alarm device fit for the ecology ceramic pot.The design proposal is of simple structure,safety in use,and avoids the environmental pollution of waste battery.The device can automatically shut off the heater circuit of induction cooker,and eliminate the potential safety hazard and save energy.It is appropriate for nonmetal heat container of induction cooker,and has great practical applicability.

  5. 21 CFR 870.1100 - Blood pressure alarm.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Blood pressure alarm. 870.1100 Section 870.1100...) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1100 Blood pressure alarm. (a) Identification. A blood pressure alarm is a device that accepts the signal from a blood...

  6. In vivo continuous and simultaneous monitoring of brain energy substrates with a multiplex amperometric enzyme-based biosensor device.

    Science.gov (United States)

    Cordeiro, C A; de Vries, M G; Ngabi, W; Oomen, P E; Cremers, T I F H; Westerink, B H C

    2015-05-15

    Enzyme-based amperometric biosensors are widely used for monitoring key biomarkers. In experimental neuroscience there is a growing interest in in vivo continuous and simultaneous monitoring of metabolism-related biomarkers, like glucose, lactate and pyruvate. The use of multiplex biosensors will provide better understanding of brain energy metabolism and its role in neuropathologies such as diabetes, ischemia, and epilepsy. We have developed and characterized an implantable multiplex microbiosensor device (MBD) for simultaneous and continuous in vivo monitoring of glucose, lactate, and pyruvate. First, we developed and characterized amperometric microbiosensors for monitoring lactate and pyruvate. In vitro evaluation allowed us to choose the most suitable biosensors for incorporation into the MBD, along with glucose and background biosensors. Fully assembled MBDs were characterized in vitro. The calculated performance parameters (LOD, LR, LRS, IMAX and appKM) showed that the multiplex MBD was highly selective and sensitive (LRS≥100 nA/mM) for each analyte and within an adequate range for in vivo application. Finally, MBDs were implanted in the mPFC of anesthetized adult male Wistar rats for in vivo evaluation. Following an equilibration period, baseline brain levels of glucose (1.3±0.2 mM), lactate (1.5±0.4 mM) and pyruvate (0.3±0.1 mM) were established. Subsequently, the MBDs recorded the responses of the animals when submitted to hyperglycemic (40% glucose i.v.) and hypoglycemic (5 U/kg insulin i.v.) challenges. Afterwards, MBDs were recalibrated to convert electrochemical readings into accurate substrate concentrations and to assess biofouling. The presented MBD can monitor simultaneously multiple biomarkers in vivo. PMID:25459054

  7. Alarm system advances and innovations

    International Nuclear Information System (INIS)

    Alarm: 'a signal (as a loud noise or flashing light) that warns or alerts; also: a device that signals... '. This statement, this definition as simple as it is sums up every alarm system for every control system that has ever existed, but what it's missing from it is the complexity and uniqueness required by a Nuclear Power Plant. With advances in computerized control and engineering technologies within these plants, the need for more comprehensive alarm control and monitoring systems is as critical as the operation itself. (authors)

  8. Paper-based enzyme immobilization for flow injection electrochemical biosensor integrated with reagent-loaded cartridge toward portable modular device.

    Science.gov (United States)

    Tan, Swee Ngin; Ge, Liya; Tan, Hsih Yin; Loke, Weng Keong; Gao, Jinrong; Wang, Wei

    2012-11-20

    Paper-based enzyme immobilization for a flow injection electrochemical biosensor integrated with a reagent-loaded cartridge toward a portable device was developed. A paper disk was immobilized with enzyme, then it was integrated in a flow cell as an electrochemical biosensor. A silicon tube reagent-loaded cartridge was integrated into the system, a complicated procedure was simplified as a one-click operation toward development for point-of-care applications. In this research, glucose oxidase (GOx) was employed as a model enzyme, silver ion as an inhibition reagent for GOx, and EDTA as a regeneration reagent. When GOx was inhibited by silver ions, glucose was introduced for electrochemical measurements before and after inhibited enzyme regeneration and the difference was caused by silver inhibition. The modular device has great potential for other applications, e.g., detection of enzyme activity and substrate. The platform based on double-test mode provided accurate results due to elimination of an average or control value in comparison with classical routine approaches. PMID:23116304

  9. Means and methods used to check radiation detection, signalling and alarm devices in the centralized environment control systems of the INB of CEN-Saclay

    International Nuclear Information System (INIS)

    Having reviewed the prescribed technical measures concerning 'systematic environment controls' in INB (Installations nucleaires de base - basic nuclear facilities) and published in the J.O. (French Official Journal) the authors briefly describe the main radiation detection, signalling and alarm systems at present installed in INB of CEN-Saclay and weigh up the extent to which their characteristics comply with the statutory texts. They then develop the means and methods set up to check on the good working order of these devices which are integrated in centralised one-piece modular analogue or informatics type control systems possible functioning anomalies being classed in two categories: logic type anomalies corresonding to a straightforward breakdown where detection is permanent; developing anomalies corresponding to poor functioning where detection requires a more critical and periodic control. The authors demonstrate the advantages offered by centralised computer type control systems

  10. The effect of a SiO2 layer on the performance of a ZnO-based SAW device for high sensitivity biosensor applications

    International Nuclear Information System (INIS)

    The properties of ZnO/SiO2/Si surface acoustic wave (SAW) love mode biosensors are studied in this paper. This specific structure is very suitable for biosensors since the reactive ZnO surface offers the opportunity for effective bio–ZnO interfaces, and the development of sensors directly on Si substrates provides the chance for full integration with read-out and signal processing circuitry in the mature Si technology. However, investigations of the dependence of buffer layer SiO2 on the performance of biosensors are very few. Therefore, the main interest of this paper is to find the relation between the properties of biosensors and the SiO2 layer. Some important results are obtained by solving the coupled electromechanical field equations. It is found that the mass loading sensitivity can be further improved by adding the SiO2 layer; furthermore, the maximal sensitivity of the biosensors can be obtained by adjusting the thicknesses of the two layers. Accordingly, consideration of the buffer layer is very important in the optimization of devices. On the other hand, it is found that the thickness of the piezoelectric guiding layer has an evident effect on the electromechanical coupling coefficient, while that of the SiO2 layer has a tiny effect on it. Moreover, we find that the effect of initial stresses on the properties of biosensors depends on the distribution of acoustic flow power in the two layers. This analysis is meaningful for the manufacture and applications of the ZnO/SiO2/Si structure love wave biosensor

  11. Results from prototypes of environmental and health alarm devices based on gaseous detectors operating in air in counting mode

    CERN Document Server

    Martinengo, P; Peskov, V; Benaben, P; Charpak, G; Breuil, P

    2011-01-01

    We have developed and successfully tested two prototypes of detectors of dangerous gases based on wire-type counters operating in air in avalanche mode: one is for radon (Rn) detection whereas the other one is for the detection of gases with an ionization potential less than the air components. Due to the operation in pulse counting mode these prototypes have sensitivities comparable to (in the case of the Rn detector) or much higher than (in the case of the detector for low ionization gases) the best commercial devices currently available on the market. We believe that due to their high sensitivity, simplicity and low cost such new detectors will find massive applications. One of them, discussed in this paper, could be the on-line monitoring of Rn for the prediction of earthquakes. (C) 2010 Elsevier B.V. All rights reserved.

  12. 公路桥涵汽车用电子限高报警系统(Ⅰ)——电子限高报警装置的原理与基本要求%Electronic Height Limit Alarm System of Highway Bridge Culvert Automobile(Ⅰ)——principle and essential requirements of electronic height limit alarm device

    Institute of Scientific and Technical Information of China (English)

    刘长生

    2011-01-01

    公路桥涵车用电子限高报警装置,是一种防止超高车辆撞坏桥涵的自动检测报警装置。文中描述这种专用电子限高装置的工作原理、基本要求以及常用的激光检测器与红外检测器的性能,为下一步进行设计公路桥涵车用电子限高报警装置提供必要的理论依据。%Electronic height limit alarm device of highway bridge culvert vehicle is an automatic detection and alarm device that prevents bridge and culver being destroyed by high vehicles.The working principles and essential requirements of the special device together with the performance of laser and infrared detectors commonly used were described in this paper,which could provide necessary theoretical basis for the design of electronic height limit alarm device applied in highway bridge culvert vehicles.

  13. Biosensors for hepatitis B virus detection

    OpenAIRE

    Yao, Chun-Yan; Fu, Wei-Ling

    2014-01-01

    A biosensor is an analytical device used for the detection of analytes, which combines a biological component with a physicochemical detector. Recently, an increasing number of biosensors have been used in clinical research, for example, the blood glucose biosensor. This review focuses on the current state of biosensor research with respect to efficient, specific and rapid detection of hepatitis B virus (HBV). The biosensors developed based on different techniques, including optical methods (...

  14. In vivo continuous and simultaneous monitoring of brain energy substrates with a multiplex amperometric enzyme-based biosensor device

    NARCIS (Netherlands)

    De Lima Braga Lopes Cordeiro, Carlos; de Vries, M.G.; Ngabi, W; Oomen, P.E.; Cremers, T.I.F.H.; Westerink, B.H.C.

    2015-01-01

    Enzyme-based amperometric biosensors are widely used for monitoring key biomarkers. In experimental neuroscience there is a growing interest in in vivo continuous and simultaneous monitoring of metabolism-related biomarkers, like glucose, lactate and pyruvate. The use of multiplex biosensors will pr

  15. Optimal Alarm Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — An optimal alarm system is simply an optimal level-crossing predictor that can be designed to elicit the fewest false alarms for a fixed detection probability. It...

  16. Biosensor nanomaterials

    CERN Document Server

    Li, Songjun; Li, He; Banerjee, Ipsita A

    2011-01-01

    Focusing on the materials suitable for biosensor applications, such as nanoparticles, quantum dots, meso- and nanoporous materials and nanotubes, this text enables the reader to prepare the respective nanomaterials for use in actual devices by appropriate functionalization, surface processing or directed self-assembly. The main detection methods used are electrochemical, optical, and mechanical, providing solutions to challenging tasks.The result is a reference for researchers and developers, disseminating first-hand information on which nanomaterial is best suited to a particular applicat

  17. Portable axle temperature alarming device for railway train%铁路列车便携式轴温报警装置的研制

    Institute of Scientific and Technical Information of China (English)

    徐超凡; 姜璐; 刘飞; 康旭韡; 曹源

    2016-01-01

    The high temperature of the train axle could bring dangerous to the train operation, so it is very important to detect train axle temperature. This research was different from the design of other axle temperature detection. Mobile phone with Android platform and ARM11 development board was used to communicate with each other in order to implement real-time monitoring of temperature. Wi-Fi technology was used to receive real-time data from the development board, and the mobile phone was used to receive data in the socket communication process, while the ARM development board worked as the client to send temperature data, so that the mechanical engineer could observe the temperature values of each axle at any position of the train. After testing, the portable axle temperature alarming device for railway train could implement the function of axle temperature detection and transmit the data of axle temperature to the intelligent handheld terminal through wireless communication.%列车轴温过高会给列车运行带来危险,因此列车轴温检测系统的意义重大。本研究不同于其他轴温检测设计,采用Android平台手机与ARM11开发板相互通信以实现对温度的实时监测。设计中采用Wi-Fi技术进行实时接收开发板采集的轴温数据,并将手机作为Socket通信过程中的服务器端接收数据,ARM开发板作为客户端发送轴温数据,使机械师能够在列车的任意位置对每一车轴的温度值进行实时观测。经测试,研制的铁路列车便携式轴温报警装置基本实现了轴温检测和无线发送轴温数据到智能手持终端的功能。

  18. Simulation and fabrication of a new novel 3D injectable biosensor for high throughput genomics and proteomics in a lab-on-a-chip device

    International Nuclear Information System (INIS)

    Biosensors are used for the detection of biochemical molecules such as proteins and nucleic acids. Traditional techniques, such as enzyme-linked immuno-sorbent assay (ELISA), are sensitive but require several hours to yield a result and usually require the attachment of a fluorophore molecule to the target molecule. Micromachined biosensors that employ electrical detection are now being developed. Here we describe one such device, which is ultrasensitive, real-time, label free and localized. It is called the nanoneedle biosensor and shows promise to overcome some of the current limitations of biosensors. The key element of this device is a 10 nm wide annular gap at the end of the needle, which is the sensitive part of the sensor. The total diameter of the sensor is about 100 nm. Any change in the population of molecules in this gap results in a change of impedance across the gap. Single molecule detection should be possible because the sensory part of the sensor is in the range of bio-molecules of interest. To increase throughput we can flow the solution containing the target molecules over an array of such structures, each with its own integrated read-out circuitry to allow ‘real-time’ detection (i.e. several minutes) of label free molecules without sacrificing sensitivity. To fabricate the arrays we used electron beam lithography together with associated pattern transfer techniques. Preliminary measurements on individual needle structures in water are consistent with the design. Since the proposed sensor has a rigid nano-structure, this technology, once fully developed, could ultimately be used to directly monitor protein quantities within a single living cell, an application that would have significant utility for drug screening and studying various intracellular signaling pathways. (paper)

  19. Biosensors : Fundamentals and Applications

    OpenAIRE

    1987-01-01

    This truly interdisciplinary work is the first substantial and comprehensive book to describe the biosensor, an important new technology combining the specificity and sensitivity of biological systems with the computing capabilities of the micro-processor. Biosensors hold enormous potential: they can monitor personal health and fitness, the food we eat, and our environment. They can replace the large analytical facilities of industrial and health services with cheap and simple devices anyone ...

  20. Safety alarms at CERN

    CERN Document Server

    Ninin, P; Henny, L

    1998-01-01

    In order to operate the CERN accelerators complex safely, the acquisition, transport and management of safety alarms is of crucial importance. The French regulatory authority [Direction de Sûreté des Installations Nucléaires de Base (INB)] defines them as Level 3 alarms; they represent as such a danger for the life and require an immediate intervention of the Fire Brigade. Safety alarms are generated by fire and flammable gas detection systems, electrical emergency stops, and other safety related systems. Level 3 alarms are transmitted for reliability reasons to their operation centre: the CERN Safety Control Room (SCR) using two different media: the hard-wired network and a computer based system. The hard-wired networks are connected to local panels summarizing in 34 security areas the overall CERN geography. The computer based system offers data management facilities such as alarm acquisition, distribution, archiving and information correlation. The Level 3 alarms system is in constant evolution in order...

  1. Understanding Clinical Alarm Safety.

    Science.gov (United States)

    Lukasewicz, Carol L; Mattox, Elizabeth Andersson

    2015-08-01

    Patient safety organizations and health care accreditation agencies recognize the significance of clinical alarm hazards. The Association for the Advancement of Medical Instrumentation, a nonprofit organization focused on development and use of safe and effective medical equipment, identifies alarm management as a major issue for health care organizations. ECRI Institute, a nonprofit organization that researches approaches for improving patient safety and quality of care, identifies alarm hazards as the most significant of the "Top Ten Health Technology Hazards" for 2014. A new Joint Commission National Patient Safety Goal focusing on clinical alarm safety contains new requirements for accredited hospitals to be fully implemented by 2016. Through a fictional unfolding case study, this article reviews selected contributing factors to clinical alarm hazards present in inpatient, high-acuity settings. Understanding these factors improves contributions by nurses to clinical alarm safety practice.

  2. 一种简易医用输液器液面监测报警装置的研制%Development of Liquid Level Monitoring & Alarming Device for Medical Infusion Apparatus

    Institute of Scientific and Technical Information of China (English)

    周文光; 魏培德; 许新建; 孔悦

    2013-01-01

    Objective To design a liquid level monitoring & alarming device for medical infusion apparatus. Methods Infrared transmitter receiver circuit, EM78P458 SCM as the control chip, external A/D circuit, alarming display circuit and reference circuit were used to develop the device, with internal rechargeable batteries involved. Results The effectiveness of the device was proved by trial operation. Conclusion The liquid level monitoring & alarming device for medical infusion apparatus can be used in the field conditions, with simple structure, high reliability, easy operation and low price.%目的:设计一种医用输液器液面监测报警装置.方法:采用红外发射和接收电路监测输液瓶液面,以EM78P458单片机为控制芯片,外接A/D电路、报警显示电路、基准电路等,实时准确监测输液瓶液面.并且,该装置设计有内置电池,充电完毕可独立使用.结果:经过实践测试,该简易医用输液器械液面监测报警装置能够准确地监测输液瓶液面,并及时通过报警信号通知医务人员.结论:该装置结构简单、可靠性高、使用简便、价格低廉、实用性好,适合野战医疗.

  3. Fundamental Aspects of Biosensors

    Directory of Open Access Journals (Sweden)

    K.Sowjanya

    2016-06-01

    Full Text Available A biosensor is an analytical device which converts a biological response into an electrical signal. The term 'biosensor' is often used to cover sensor devices used in order to determine the concentration of substances and other parameters of biological interest even where they do not utilize a biological system directly. This very broad definition is used by some scientific journals (e.g. Biosensors, Elsevier Applied Science but will not be applied to the coverage here. The emphasis of this Chapter concerns enzymes as the biologically responsive material, but it should be recognized that other biological systems may be utilized by biosensors, for example, whole cell metabolism, ligand binding and the antibody-antigen reaction. Biosensors represent a rapidly expanding field, at the present time, with an estimated 60% annual growth rate; the major impetus coming from the health-care industry (e.g. 6% of the western world are diabetic and would benefit from the availability of a rapid, accurate and simple biosensor for glucose but with some pressure from other areas, such as food quality appraisal and environmental monitoring. The estimated world analytical market is about 12,000,000,000 year- 1 of which 30% is in the health care area. There is clearly a vast market expansion potential as less than 0.1% of this market is currently using biosensors. Research and development in this field is wide and multidisciplinary, spanning biochemistry, bioreactor science, physical chemistry, electrochemistry, electronics and software engineering. Most of this current endeavour concerns potentiometric and amperometric biosensors and colorimetric paper enzyme strips. However, all the main transducer types are likely to be thoroughly examined, for use in biosensors, over the next few years.

  4. Perspectives on use of personal alarms by older fallers

    Directory of Open Access Journals (Sweden)

    Kylie Johnston

    2010-08-01

    Full Text Available Kylie Johnston1, Karen Grimmer-Somers1, Michele Sutherland21International Centre for Allied Health Evidence, University of South Australia, Adelaide; 2Falls Prevention Unit, Department of Health, Government of South Australia, Adelaide, AustraliaBackground: Personal alarms are proposed as a reliable mechanism for older people to obtain assistance after falling. However, little is known about how older people feel about owning and using personal alarms.Aim: This paper reports on experiences of independently living older people, who have recently fallen, regarding alarm use and their independence.Method: Volunteers older than 65 years who had sustained a fall in the previous six months were sought via community invitations. Semistructured telephone interviews were conducted to gain information about their fall and their perspectives on personal alarm use. Interviews were content-analyzed to identify key concepts and themes.Results: Thirty-one interviews were conducted. Twenty callers owned personal alarms. Four subgroups of older fallers were identified; the first group used personal alarms effectively and were advocates for their benefits, the second group owned an alarm but did not use it effectively, the third group did not own alarms mostly because of cost, although were receptive to an alarm should one be provided, and the fourth group did not have an alarm and would not use it even if it was provided.Discussion: Personal alarms produce positive experiences when used effectively by the right people. The cost of personal alarms prohibits some older fallers from being effective alarm users. However, other elderly fallers remain unwilling to consider alarm use even if one was provided. In view of their cost, personal alarms should be targeted to people who will benefit most. ­Alternative strategies should be considered when alarms are unlikely to be used appropriately.Keywords: personal alarm devices, falls, older people, patient perspective

  5. Intelligent Alarm Management System (IAMS)

    International Nuclear Information System (INIS)

    A large number of alarms in a nuclear power plant (NPP) are related to one causative event/alarm. When such an event happens, it triggers a cascade of alarms (called alarm avalanche) that comes in quick succession. These alarms may or may not come in a particular time-sequence each time the cause event is triggered. Alarm avalanches in an emergency situation can affect the performance of even the most seasoned operators. If a cause-consequence relationship can be established among a set of alarms, then such avalanches can be avoided by annunciating only the rootcause alarm. Intelligent Alarm Management System (IAMS) is a knowledge-based alarm processing system to reduce the number of presented alarms. The processing is based on the functional cause-consequence knowledge-base of the plant, wherein an alarm on a function denotes degradation/unavailability of the function.The knowledge is modeled using a graphical construct called Function Graph. (author)

  6. Simultaneous real-time monitoring of oxygen consumption and hydrogen peroxide production in cells using our newly developed chip-type biosensor device

    Directory of Open Access Journals (Sweden)

    Ankush ePrasad

    2016-03-01

    Full Text Available All living organisms bear its defense mechanism. Immune cells during invasion by foreign body undergoes phagocytosis during which monocyte and neutrophil produces reactive oxygen species (ROS. The ROS generated in animal cells are known to be involved in several diseases and ailments, when generated in excess. Therefore, if the ROS generated in cells can be measured and analyzed precisely, it can be employed in immune function evaluation and disease detection. The aim of the current study is to introduce our newly developed chip-type biosensor device with high specificity and sensitivity. It comprises of counter electrode and working electrodes I and II. The counter electrode is a platinum plate while the working electrodes I and II are platinum microelectrode and osmium-horseradish peroxidase modified gold electrode, respectively which acts as oxygen and hydrogen peroxide (H2O2 detection sensors. Simultaneous measurement of oxygen consumption and H2O2 generation were measured in animal cells under the effect of exogenous addition of differentiation inducer, phorbol 12-myristate 13-acetate. The results obtained showed considerable changes in reduction currents in the absence and presence of inducer. Our newly developed chip-type biosensor device is claimed to be a useful tool for real-time monitoring of the respiratory activity and precise detection of H2O2 in cells. It can thus be widely applied in biomedical research and in clinical trials being an advancement over other H2O2 detection techniques.

  7. Simultaneous Real-Time Monitoring of Oxygen Consumption and Hydrogen Peroxide Production in Cells Using Our Newly Developed Chip-Type Biosensor Device

    Science.gov (United States)

    Prasad, Ankush; Kikuchi, Hiroyuki; Inoue, Kumi Y.; Suzuki, Makoto; Sugiura, Yamato; Sugai, Tomoya; Tomonori, Amano; Tada, Mika; Kobayashi, Masaki; Matsue, Tomokazu; Kasai, Shigenobu

    2016-01-01

    All living organisms bear its defense mechanism. Immune cells during invasion by foreign body undergoes phagocytosis during which monocyte and neutrophil produces reactive oxygen species (ROS). The ROS generated in animal cells are known to be involved in several diseases and ailments, when generated in excess. Therefore, if the ROS generated in cells can be measured and analyzed precisely, it can be employed in immune function evaluation and disease detection. The aim of the current study is to introduce our newly developed chip-type biosensor device with high specificity and sensitivity. It comprises of counter electrode and working electrodes I and II. The counter electrode is a platinum plate while the working electrodes I and II are platinum microelectrode and osmium-horseradish peroxidase modified gold electrode, respectively which acts as oxygen and hydrogen peroxide (H2O2) detection sensors. Simultaneous measurement of oxygen consumption and H2O2 generation were measured in animal cells under the effect of exogenous addition of differentiation inducer, phorbol 12-myristate 13-acetate. The results obtained showed considerable changes in reduction currents in the absence and presence of inducer. Our newly developed chip-type biosensor device is claimed to be a useful tool for real-time monitoring of the respiratory activity and precise detection of H2O2 in cells. It can thus be widely applied in biomedical research and in clinical trials being an advancement over other H2O2 detection techniques. PMID:27065878

  8. Smart smoke alarm

    Energy Technology Data Exchange (ETDEWEB)

    Warmack, Robert J. Bruce; Wolf, Dennis A; Frank, Steven Shane

    2015-04-28

    Methods and apparatus for smoke detection are disclosed. In one embodiment, a smoke detector uses linear discriminant analysis (LDA) to determine whether observed conditions indicate that an alarm is warranted.

  9. Speech Alarms Pilot Study

    Science.gov (United States)

    Sandor, Aniko; Moses, Haifa

    2016-01-01

    Speech alarms have been used extensively in aviation and included in International Building Codes (IBC) and National Fire Protection Association's (NFPA) Life Safety Code. However, they have not been implemented on space vehicles. Previous studies conducted at NASA JSC showed that speech alarms lead to faster identification and higher accuracy. This research evaluated updated speech and tone alerts in a laboratory environment and in the Human Exploration Research Analog (HERA) in a realistic setup.

  10. HOME INSECURITY: NO ALARMS, FALSE ALARMS, AND SIGINT

    Energy Technology Data Exchange (ETDEWEB)

    Lamb, Logan M [ORNL

    2014-01-01

    The market share of home security systems has substantially increased as vendors incorporate more desirable features: intrusion detection, automation, wireless, and LCD touch panel controls. Wireless connectivity allows vendors to manufacture cheaper, more featureful products that require little to no home modification to install. Consumer win, since adding devices is easier. The result: an ostensibly more secure, convenient, and connected home for a larger number of citizens. Sadly, this hypothesis is flawed; the idea of covering a home with more security sensors does not translate into a more secure home. Additionally, the number of homes using these vulnerable systems is large, and the growth rate is increasing producing a even larger problem. In this talk, I will demonstrate a generalized approach for compromising three systems: ADT, the largest home security dealer in North America; Honeywell, one of the largest manufacturers of security devices; and Vivint, a top 5 security dealer. We will suppress alarms, create false alarms, and collect artifacts that facilitate tracking the movements of individuals in their homes.

  11. The future of biosensors

    NARCIS (Netherlands)

    Bergveld, P.

    1996-01-01

    Since the development of the glucose sensor by Clark and Lyons in 1962, generally recognized as the first biosensor, many types of sensors have been developed in which a physical or chemical transducer is provided with a layer containing a biological sensing element. The resulting device is called a

  12. Biosensors for hepatitis B virus detection.

    Science.gov (United States)

    Yao, Chun-Yan; Fu, Wei-Ling

    2014-09-21

    A biosensor is an analytical device used for the detection of analytes, which combines a biological component with a physicochemical detector. Recently, an increasing number of biosensors have been used in clinical research, for example, the blood glucose biosensor. This review focuses on the current state of biosensor research with respect to efficient, specific and rapid detection of hepatitis B virus (HBV). The biosensors developed based on different techniques, including optical methods (e.g., surface plasmon resonance), acoustic wave technologies (e.g., quartz crystal microbalance), electrochemistry (amperometry, voltammetry and impedance) and novel nanotechnology, are also discussed. PMID:25253948

  13. Gynecological cancer alarm symptoms:

    DEFF Research Database (Denmark)

    Balasubramaniam, Kirubakaran; Ravn, Pernille; dePont Christensen, René;

    2016-01-01

    INTRODUCTION: To determine the proportion of patients who were referred to specialist care after reporting gynecological cancer alarm symptoms to their general practitioner. To investigate whether contact with specialist care was associated with lifestyle factors or socioeconomic status. MATERIAL...... and odds ratios (ORs) for associations between specialist care contact, lifestyle factors and socioeconomic status. RESULTS: The study included 25 866 non-pregnant women; 2957 reported the onset of at least one gynecological cancer alarm symptom, and 683 of these (23.1%) reported symptoms to their general......: Educational level influence contact with specialist care among patients with gynecological cancer alarm symptoms. Future studies should investigate inequalities in access to the secondary healthcare system. This article is protected by copyright. All rights reserved....

  14. Tiny Medicine: Nanomaterial-Based Biosensors

    Directory of Open Access Journals (Sweden)

    Nelson Watts

    2009-11-01

    Full Text Available Tiny medicine refers to the development of small easy to use devices that can help in the early diagnosis and treatment of disease. Early diagnosis is the key to successfully treating many diseases. Nanomaterial-based biosensors utilize the unique properties of biological and physical nanomaterials to recognize a target molecule and effect transduction of an electronic signal. In general, the advantages of nanomaterial-based biosensors are fast response, small size, high sensitivity, and portability compared to existing large electrodes and sensors. Systems integration is the core technology that enables tiny medicine. Integration of nanomaterials, microfluidics, automatic samplers, and transduction devices on a single chip provides many advantages for point of care devices such as biosensors. Biosensors are also being used as new analytical tools to study medicine. Thus this paper reviews how nanomaterials can be used to build biosensors and how these biosensors can help now and in the future to detect disease and monitor therapies.

  15. 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.

  16. Biosensors in Endocrinology- Review Article

    Directory of Open Access Journals (Sweden)

    Farnoush FARIDBOD

    2015-10-01

    Full Text Available Biosensors are classes of sensors in which at least a biological process is used in sensing procedure. They are generally composed of three parts: a sensing element, a transducer, and a signal processor (or detector. They can be categorized by type of sensing materials or by detection techniques. From their invention time up to now, various biological species have been analyzed using variety of biosensors. They have been widely used for environmental, industrial, pharmaceutical and clinical applications in many research papers. Perhaps the number of biosensors which had a chance to commercialize and enter to the market is limited, but by recent developments in science and technology, day-by-day, the number of commercial biosensors are growing. Their importance in clinical medicine can be found in determination of biomarkers for early diagnosis of disease or for control and manage of them in point-of-care devices. Diagnosis and control of many endocrine diseases and metabolic disorders depend strongly on determination of chemicals, hormones and antibodies. A large number of biosensors research studies have focused on determination of these biomolecules. One of the famous commercial biosensor is widely used in management of diabetes is glucometer. They are portable commercial biosensors which measure the amount of glucose in a blood drop. The main challenges in designing biosensors are decrease the limit of detection, increasing the sensitivity and accuracy in an analysis, increasing lifetime and miniaturization. Even scientists are now trying to develop biosensors for non-invasive measurements of biomarkers in saliva or tears. Keywords: Biosensor, Endocrinology, Point-of-care device, Diabetes, Glucometer 

  17. 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.

  18. Recent Trends in Biosensors

    Science.gov (United States)

    Karube, Isao

    The determination of organic compounds in foods is very important in food industries. A various compounds are contained in foods, selective determination methods are required for food processing and analysis. Electrochemical monitoring devices (biosensors) employing immobilized biocatalysts such as immobilized enzymes, organelles, microorganisms, and tissue have definite advantages. The enzyme Sensors consisted of immobilized enzymes and electrochemical devices. Enzyme sensors could be used for the determination of sugars, amino acids, organic acids, alcohols, lipids, nucleic acid derivatives, etc.. Furthermore, a multifunctional biosensor for the determination of several compounds has been developed for food processing. On the other hand, microbial sensors consisted of immobilized microorganisms and electrodes have been used for industrial and environmental analysis. Microbial sensors were applied for the determination of sugars, organic acids, alcohols, amino acids, mutagens, me thane, ammonia, and BOD. Furthermore, micro-biosensors using immobilized biocatalysts and ion sensitive field effect transistor or microelectrodes prepared by silicon fabrication technologies have been developed for medical ap. plication and food processing. This review summarizes the design and application of biosensors.

  19. Dynamic alarm response procedures

    International Nuclear Information System (INIS)

    The Dynamic Alarm Response Procedure (DARP) system provides a robust, Web-based alternative to existing hard-copy alarm response procedures. This paperless system improves performance by eliminating time wasted looking up paper procedures by number, looking up plant process values and equipment and component status at graphical display or panels, and maintenance of the procedures. Because it is a Web-based system, it is platform independent. DARP's can be served from any Web server that supports CGI scripting, such as ApacheR, IISR, TclHTTPD, and others. DARP pages can be viewed in any Web browser that supports Javascript and Scalable Vector Graphics (SVG), such as NetscapeR, Microsoft Internet ExplorerR, Mozilla FirefoxR, OperaR, and others. (authors)

  20. 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

  1. A CMOS self-powered front-end architecture for subcutaneous event-detector devices

    CERN Document Server

    Colomer-Farrarons, Jordi

    2011-01-01

    A CMOS Self-Powered Front-End Architecture for Subcutaneous Event-Detector Devices presents the conception and prototype realization of a Self-Powered architecture for subcutaneous detector devices. The architecture is designed to work as a true/false (event detector) or threshold level alarm of some substances, ions, etc. that are detected through a three-electrodes amperometric BioSensor approach. The device is conceived as a Low-Power subcutaneous implantable application powered by an inductive link, one emitter antenna at the external side of the skin and the receiver antenna under the ski

  2. Bed-exit alarm effectiveness

    Science.gov (United States)

    Capezuti, Elizabeth; Brush, Barbara L.; Lane, Stephen; Rabinowitz, Hannah U.; Secic, Michelle

    2009-01-01

    This study describes the accuracy of two types of bed-exit alarms to detect bed-exiting body movements: pressure-sensitive and a pressure sensitive combined with infrared beam detectors (dual sensor system). We also evaluated the occurrence of nuisance alarms, or alarms that are activated when a participant does not attempt to get out of bed. Fourteen nursing home residents were directly observed for a total of 256 nights or 1,636.5 hours; an average of 18.3 ± 22.3 (± S.D.) nights/participant for an average of 6.4 ± 1.2 hours/night. After adjusting for body movements via repeated measures, Poisson regression modeling, the least squares adjusted means show a marginally significant difference between the type of alarm groups on the number of true positives (mean/S.E.M. = 0.086/1.617) for pressure-sensitive vs. dual sensor alarm (0.593/1.238; p = 0.0599) indicating that the dual sensor alarm may have a higher number of true positives. While the dual sensor bed-exit alarm was more accurate than the pressure sensitive alarm in identifying bed-exiting body movements and reducing the incidence of false alarms, false alarms were not eliminated altogether. Alarms are not a substitute for staff; adequate staff availability is still necessary when residents need or wish to exit bed. PMID:18508138

  3. 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.

  4. Implementation of alarm system for vibration monitoring of KOMAC facility

    International Nuclear Information System (INIS)

    For operating 100 MeV linac, Devices have to be operated in certain order. Thus malfunction of a device cause damage to linac and related devices. To protect linac, machine protect system (MPS) has been developed. The MPS protects the components by monitoring hardwired signals. When values of operating parameters go beyond or below limit, alarm will be generated and interlock system which stops related devices in certain sequence will run. Other factor, giving damage to linac is disaster. A strong vibration such as earthquake causes malfunction of devices and damage to linac. Against disaster, the monitoring system based on Experimental Physics and Industrial Control System (EPICS) was implemented. Configuration and Implementation of the monitoring system are presented and some preliminary results are reported. KOMAC implemented alarm system for a strong vibration and fire. Alarm is generated in unusual situation. Coping rapidly with situation, damages for Linac and related devices can be reduced

  5. Graphene-based biosensors

    Science.gov (United States)

    Lebedev, A. A.; Davydov, V. Yu.; Novikov, S. N.; Litvin, D. P.; Makarov, Yu. N.; Klimovich, V. B.; Samoilovich, M. P.

    2016-07-01

    Results of developing and testing graphene-based sensors capable of detecting protein molecules are presented. The biosensor operation was checked using an immunochemical system comprising fluorescein dye and monoclonal antifluorescein antibodies. The sensor detects fluorescein concentration on a level of 1-10 ng/mL and bovine serum albumin-fluorescein conjugate on a level of 1-5 ng/mL. The proposed device has good prospects for use for early diagnostics of various diseases.

  6. Biosensors in clinical chemistry: An overview

    OpenAIRE

    Sathish Babu Murugaiyan; Ramesh Ramasamy; Niranjan Gopal; Kuzhandaivelu, V.

    2014-01-01

    Biosensors are small devices that employ biological/biochemical reactions for detecting target analytes. Basically, the device consists of a biocatalyst and a transducer. The biocatalyst may be a cell, tissue, enzyme or even an oligonucleotide. The transducers are mainly amperometric, potentiometric or optical. The classification of biosensors is based on (a) the nature of the recognition event or (b) the intimacy between the biocatalyst and the transducer. Bioaffinity and biocatalytic device...

  7. Polymer Based Biosensors for Medical Applications

    DEFF Research Database (Denmark)

    Cherré, Solène; Rozlosnik, Noemi

    2015-01-01

    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...

  8. Zinc oxide interdigitated electrode for biosensor application

    Science.gov (United States)

    Sin L., L.; Arshad, M. K. Md.; Fathil, M. F. M.; Adzhri, R.; M. Nuzaihan M., N.; Ruslinda, A. R.; Gopinath, Subash C. B.; Hashim, U.

    2016-07-01

    In biosensors, zinc oxide (ZnO) thin film plays a crucial role in term of stability, sensitivity, biocompatibility and low cost. Interdigitated electrode (IDE) design is one of the device architecture in biosensor for label free, stability and sensitivity. In this paper, we discuss the fabrication of zinc oxide deposited on the IDE as a transducer for sensing of biomolecule. The formation of APTES had increase the performance of the surface functionalization..Furthermore we extend the discuss on the surface functionalization process which is utilized for probe attachment onto the surface of biosensor through surface immobilization process, thus enables the sensing of biomolecules for biosensor application.

  9. The Coast Alarm System Editor

    International Nuclear Information System (INIS)

    The OECD Halden Reactor Project has for several years worked in the field of alarm handling. COAST was developed based on long experience with several different methods for identification of plant status and detection of plant anomalies. COAST has been delivered to a number of different organisations which generate their own applications. With COAST one can implement many alarm generation or structuring methods. So far, the alarm system is defined using a COAST language, COLA. Now, a first version of an editor to implement alarm systems is available, to support alarm system designers to write and structure their COLA code. It is developed based on general guidelines for user interface design and a thorough discussion of different editor types. The most important functionality needed when designing alarm systems for complex processes was emphasized when choosing the type of editor. A structure-oriented editor is currently implemented, and the report gives a description for how to include graphic features towards a more complete editor in the future. Support and encouragement for reuse of code is obtained by defining classes in a class library browser. Separate applications with their specific object definitions are constructed in an application browser. In this way the alarm classes from the class libraries can easily be used in several applications. The application browser offers the possibility to organize the alarm objects in a structured hierarchy. In big complex alarm systems such a structuring feature is of vital importance to keep the overview of the alarm system and to perform maintenance. (author)

  10. 基于CAN总线技术的工业现场故障报警装置的设计%Design of Fault Alarm Device of Industry Field based on CAN Bus Technology

    Institute of Scientific and Technical Information of China (English)

    王斌

    2015-01-01

    随着工业生产的高度自动化和信息化,现场总线越来越多地应用于工业控制的各个领域。本文通过设计基于CAN总线通信协议的现场故障报警装置,实现了工业现场的故障检测系统与工业数字化信息平台的数据共享,软件上采用抗干扰的设计方法,保证了系统的稳定性与安全性,具有良好的市场前景。%With the development of super automation and information in the industrial production,more and more Field Bus are used in the control realm nowadays. In the paper, a field fault alarm device is designed based on CAN bus communication protocol to realize the field of industrial fault detection and data sharing, and an anti-interferance software design method is using for stability and security of system, so we believe that this system wil have good market potential.

  11. Alarm management a comprehensive guide

    CERN Document Server

    Hollifield, Bill R

    2011-01-01

    In this second edition, Alarm Management: A Comprehensive Guide, various problems of alarm systems are covered with precise guidance on how they come about and how to effectively correct them. It is written by individuals with vast experience in the different plants, processes, and environments requiring effective alarm management. The second edition is filled with good examples and explanations of procedures, with practical lists and tips on how one should proceed. It is based on hundreds of successful projects.

  12. Fundamental Principles of Alarm Design

    DEFF Research Database (Denmark)

    Us, Tolga; Jensen, Niels; Lind, Morten;

    2011-01-01

    Traditionally alarms are designed on the basis of empirical guidelines rather than on a sound scientific framework rooted in a theoretical foundation for process and control system design. This paper proposes scientific principles and a methodology for design of alarms based on a functional...... be applied to any engineering system which can be modeled by MFM. The methodology provides a set of alarms which can facilitate event interpretation and operator support for abnormal situation management. The proposed design methodology provides the information content of the alarms, but does not deal...

  13. Biosensoric potential of microbial fuel cells.

    Science.gov (United States)

    Schneider, György; Kovács, Tamás; Rákhely, Gábor; Czeller, Miklós

    2016-08-01

    Recent progress in microbial fuel cell (MFC) technology has highlighted the potential of these devices to be used as biosensors. The advantages of MFC-based biosensors are that they are phenotypic and can function in either assay- or flow-through formats. These features make them appropriate for contiguous on-line monitoring in laboratories and for in-field applications. The selectivity of an MFC biosensor depends on the applied microorganisms in the anodic compartment where electron transfer (ET) between the artificial surface (anode) and bacterium occurs. This process strongly determines the internal resistance of the sensoric system and thus influences signal outcome and response time. Despite their beneficial characteristics, the number of MFC-based biosensoric applications has been limited until now. The aim of this mini-review is to turn attention to the biosensoric potential of MFCs by summarizing ET mechanisms on which recently established and future sensoric devices are based. PMID:27401925

  14. Fiber based optofluidic biosensors

    Science.gov (United States)

    Lismont, M.; Vandewalle, N.; Joris, B.; Dreesen, L.

    2014-09-01

    Medicinal diagnosis requires the development of innovative devices allowing the detection of small amounts of biological species. Among the large variety of available biosensors, the ones based on fluorescence phenomenon are really promising. Here, we show a prototype of the basic unit of a multi-sensing biosensor combining optics and microfluidics benefits. This unit makes use of two crossed optical fibers: the first fiber is used to carry small probe molecules droplets and excite fluorescence, while the second one is devoted to target molecules droplets transport and fluorescence detection. Within this scheme, the interaction takes place in each fiber node. The main benefits of this detection setup are the absence of fibers functionalization, the use of microliter volumes of target and probe species, their separation before interaction, and a better detection limit compared to cuvettes setups.

  15. 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.

  16. Electrochemical biosensors and nanobiosensors.

    Science.gov (United States)

    Hammond, Jules L; Formisano, Nello; Estrela, Pedro; Carrara, Sandro; Tkac, Jan

    2016-06-30

    Electrochemical techniques have great promise for low-cost miniaturised easy-to-use portable devices for a wide range of applications-in particular, medical diagnosis and environmental monitoring. Different techniques can be used for biosensing, with amperometric devices taking the central role due to their widespread application in glucose monitoring. In fact, glucose biosensing takes an approximately 70% share of the biosensor market due to the need for diabetic patients to monitor their sugar levels several times a day, making it an appealing commercial market.In this review, we present the basic principles of electrochemical biosensor devices. A description of the different generations of glucose sensors is used to describe in some detail the operation of amperometric sensors and how the introduction of mediators can enhance the performance of the sensors. Electrochemical impedance spectroscopy is a technique being increasingly used in devices due to its ability to detect variations in resistance and capacitance upon binding events. Novel advances in electrochemical sensors, due to the use of nanomaterials such as carbon nanotubes and graphene, are presented as well as future directions that the field is taking. PMID:27365037

  17. Electrochemical biosensors and nanobiosensors.

    Science.gov (United States)

    Hammond, Jules L; Formisano, Nello; Estrela, Pedro; Carrara, Sandro; Tkac, Jan

    2016-06-30

    Electrochemical techniques have great promise for low-cost miniaturised easy-to-use portable devices for a wide range of applications-in particular, medical diagnosis and environmental monitoring. Different techniques can be used for biosensing, with amperometric devices taking the central role due to their widespread application in glucose monitoring. In fact, glucose biosensing takes an approximately 70% share of the biosensor market due to the need for diabetic patients to monitor their sugar levels several times a day, making it an appealing commercial market.In this review, we present the basic principles of electrochemical biosensor devices. A description of the different generations of glucose sensors is used to describe in some detail the operation of amperometric sensors and how the introduction of mediators can enhance the performance of the sensors. Electrochemical impedance spectroscopy is a technique being increasingly used in devices due to its ability to detect variations in resistance and capacitance upon binding events. Novel advances in electrochemical sensors, due to the use of nanomaterials such as carbon nanotubes and graphene, are presented as well as future directions that the field is taking.

  18. Electrochemical biosensors and nanobiosensors

    Science.gov (United States)

    Hammond, Jules L.; Formisano, Nello; Carrara, Sandro; Tkac, Jan

    2016-01-01

    Electrochemical techniques have great promise for low-cost miniaturised easy-to-use portable devices for a wide range of applications–in particular, medical diagnosis and environmental monitoring. Different techniques can be used for biosensing, with amperometric devices taking the central role due to their widespread application in glucose monitoring. In fact, glucose biosensing takes an approximately 70% share of the biosensor market due to the need for diabetic patients to monitor their sugar levels several times a day, making it an appealing commercial market. In this review, we present the basic principles of electrochemical biosensor devices. A description of the different generations of glucose sensors is used to describe in some detail the operation of amperometric sensors and how the introduction of mediators can enhance the performance of the sensors. Electrochemical impedance spectroscopy is a technique being increasingly used in devices due to its ability to detect variations in resistance and capacitance upon binding events. Novel advances in electrochemical sensors, due to the use of nanomaterials such as carbon nanotubes and graphene, are presented as well as future directions that the field is taking. PMID:27365037

  19. The Quantitative Overhead Analysis for Effective Task Migration in Biosensor Networks

    OpenAIRE

    Sung-Min Jung; Tae-Kyung Kim; Jung-Ho Eom; Tai-Myoung Chung

    2013-01-01

    We present a quantitative overhead analysis for effective task migration in biosensor networks. A biosensor network is the key technology which can automatically provide accurate and specific parameters of a human in real time. Biosensor nodes are typically very small devices, so the use of computing resources is restricted. Due to the limitation of nodes, the biosensor network is vulnerable to an external attack against a system for exhausting system availability. Since biosensor nodes gener...

  20. 40 CFR 267.34 - When must personnel have access to communication equipment or an alarm system?

    Science.gov (United States)

    2010-07-01

    ... to an internal alarm or emergency communication device, either directly or through visual or voice... communication equipment or an alarm system? 267.34 Section 267.34 Protection of Environment ENVIRONMENTAL... have access to communication equipment or an alarm system? (a) Whenever hazardous waste is being...

  1. Alarming increase in refugees.

    Science.gov (United States)

    1992-01-01

    Over the past decade and half there has been an alarming worldwide increase in refugees. The total rose form 2.8 million in 1976 to 8.2 million in 1980, to 17.3 million in 1990. Africa's refugees rose from 1.2 million in 1976 to 5.6 million in 1990. Asia's increase over this period was much more rapid--from a mere 180,000 to 8 million. In the Americas the numbers more than trebled, from 770,000 to 2.7 million. Europe was the smallest increase, from 570,000 to 894,000. International law defines a refugee as someone outside of their own country, who has a well-founded fear of persecution because of their political or religious beliefs or ethnic origin, and who cannot turn to their own country for protection. Most refugees are genuine by this definition. The increase reflects, in part, fallout from the cold war. Ethiopia, Mozambique and Angola accounted for almost 1/2 of Africa's refugees; Afghanistan alone for 3/4 of Asia's total. They fled, for the most part, from 1 poor country into another, where they added to shortages of land and fuelwood, and intensified environmental pressure. Malawi, 1 of the poorest countries in the world, is sheltering perhaps as many as 750,000 refugees from the war in Mozambique. But among these refugees--especially among those who turned to the rich countries for asylum--were an increasing number of people who were not suffering political persecution. Driven out of their homes by the collapse of their environment or economic despair, and ready to take any means to get across borders, they are a new category: economic and environmental refugees. The most spectacular attempts hit the television screens: the Vietnamese boat people, ships festooned with Albanians. Behind the headlines there was a growing tide of asylum seekers. The numbers rose 10-fold in Germany from 1983 to 1990. In Switzerland they multiplied by 4 times. In Europe, as a whole, they grew from 71,000 in 1983 to an estimated 550,000 in 1990. In 1990 the numbers threatened to

  2. Biosensors: tool for food borne pathogen detection

    Directory of Open Access Journals (Sweden)

    Heena Sharma

    2013-12-01

    Full Text Available A paramount and alluring sphere of research, now-a-days, is food analysis, because of the breakneck augmentation of food enterprise and highly hightened maneuverability of today's populations. The management of food quality is very indispensable both for consumer safeguard as well as the food corporations. The biosensors' application in the field of food analysis is quite propitious for the revealing of food borne pathogens. Biosensor, an analytical device, transforms a biological response into an electrical signal. Bioreceptors and transducers are the two main components of a biosensor. Bioreceptor or biorecognition element is the one which leads to the recognition of target analyte and a transducer, for the conversion of recognized event into a measurable electrical signal. The development of biosensors improved the sensitivity and selectivity of detection techniques for food borne pathogens and is rapid, reliable, effective and highly suitable when used in in situ analysis. Since the security in the food supply becomes crucial because of increased perception among consumers and vying nature of food industries, the necessity for expeditious, low volume and sensitive biosensor devices has productively increased. Nevertheless, till date, a very few biosensor systems are available commercially such as Biacore, SpreetaTM, Reichert SR 7000, Analyte 2000, RAPTOR etc. Since, there is ever growing concern regarding safe food and water supply, it is very obvious that the demand for rapid detecting biosensors will also be increasing at par.

  3. Design Strategies for Aptamer-Based Biosensors

    Directory of Open Access Journals (Sweden)

    Kun Han

    2010-05-01

    Full Text Available 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.

  4. Biosensors a promising future in measurements

    International Nuclear Information System (INIS)

    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

  5. REVIEW ARTICLE: Environmental applications of analytical biosensors

    Science.gov (United States)

    Marco, María-Pilar; Barceló, Damià

    1996-11-01

    A review of the fundamental aspects and environmental applications of biosensors is presented. The bases of different transducer principles such as electrochemical, optical and piezoelectric are discussed. Various examples are given of the applications of such principles to develop immunosensor devices to determine common environmental contaminants. Attention is also paid to catalytic biosensors, using enzymes as sensing elements. Biosensor devices based on the use of cholinesterase and various oxidase enzymes such as tyrosinase, laccase, peroxidase and aldehyde dehydrogenase are reported. Some examples are given of the applications of other biomolecules such as whole cells, DNA or proteins, to determine pollution. Validation studies are presented comparing biosensors with chromatographic techniques to determine organophosphorus pesticides and phenolic compounds in environmental samples.

  6. Multiplexed Biosensors for Mycotoxins.

    Science.gov (United States)

    Maragos, Chris M

    2016-07-01

    Significant progress has been made in the development of biosensors that can be used to detect low-MW toxins produced by fungi (mycotoxins). The number of formats that have been investigated is impressive and is an indication of the importance attached to finding easy-to-use, accurate, and rapid methods for detecting these toxins in commodities and foods. This review explores the details of multiplexed biosensors based on many formats, including multiplexed immunoassays, suspension arrays, membrane-based devices (flow-through and immunochromatographic), and planar microarrays. Each assay format has its own strengths and areas that need improvement. Certain formats, such as multiplexed immunochromatographic devices, are well developed and relatively easy to use, and in some cases, commercial products are being sold. Others, such as the suspension arrays and microarrays, are laboratory-based assays that, although more complicated, are also more amenable to a larger scale of multiplexing. The diversity of such efforts and the multitude of formats under investigation suggest that multiple solutions will be found to satisfy the need for multiplexed toxin detection. PMID:27455928

  7. 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.

  8. Biosensors in clinical chemistry: An overview

    Directory of Open Access Journals (Sweden)

    Sathish Babu Murugaiyan

    2014-01-01

    Full Text Available Biosensors are small devices that employ biological/biochemical reactions for detecting target analytes. Basically, the device consists of a biocatalyst and a transducer. The biocatalyst may be a cell, tissue, enzyme or even an oligonucleotide. The transducers are mainly amperometric, potentiometric or optical. The classification of biosensors is based on (a the nature of the recognition event or (b the intimacy between the biocatalyst and the transducer. Bioaffinity and biocatalytic devices are examples for the former and the first, whereas second and third generation instruments are examples for the latter. Cell-based biosensors utilizing immobilized cells, tissues as also enzyme immunosensors and DNA biosensors find variegated uses in diagnostics. Enzyme nanoparticle-based biosensors make use of small particles in the nanometer scale and are currently making a mark in laboratory medicine. Nanotechnology can help in optimizing the diagnostic biochips, which would facilitate sensitive, rapid, accurate and precise bedside monitoring. Biosensors render themselves as capable diagnostic tools as they meet most of the above-mentioned criteria.

  9. Biosensors in clinical chemistry: An overview.

    Science.gov (United States)

    Murugaiyan, Sathish Babu; Ramasamy, Ramesh; Gopal, Niranjan; Kuzhandaivelu, V

    2014-01-01

    Biosensors are small devices that employ biological/biochemical reactions for detecting target analytes. Basically, the device consists of a biocatalyst and a transducer. The biocatalyst may be a cell, tissue, enzyme or even an oligonucleotide. The transducers are mainly amperometric, potentiometric or optical. The classification of biosensors is based on (a) the nature of the recognition event or (b) the intimacy between the biocatalyst and the transducer. Bioaffinity and biocatalytic devices are examples for the former and the first, whereas second and third generation instruments are examples for the latter. Cell-based biosensors utilizing immobilized cells, tissues as also enzyme immunosensors and DNA biosensors find variegated uses in diagnostics. Enzyme nanoparticle-based biosensors make use of small particles in the nanometer scale and are currently making a mark in laboratory medicine. Nanotechnology can help in optimizing the diagnostic biochips, which would facilitate sensitive, rapid, accurate and precise bedside monitoring. Biosensors render themselves as capable diagnostic tools as they meet most of the above-mentioned criteria. PMID:24627875

  10. Functional alarming and information retrieval

    International Nuclear Information System (INIS)

    This paper deals with two facets of the design and efficient utilisation by operating personnel of computer-based interfaces for monitoring and the supervisory control of complex industrial systems - e.g., power stations, chemical plants, etc. These are alarming and information retrieval both of which are extremely sensitive to computerisation. For example, the advent of computers for display requires that some means of assuring easy and rapid access to large amounts of relevant stored information be found. In this paper, alarming and information retrieval are linked together through a multilevel functional description of the target plant. This representation serves as a framework for structuring the access to information as well as defining associated ''alarms'' at the various descriptive levels. Particular attention is paid to the level where mass and energy flows and balances are relevant. It is shown that the number of alarms here is reduced considerably while information about content and interrelationships is enhanced - which at the same time eases the retrieval problem. (author)

  11. Integration of biosensors into digital microfluidics: Impact of hydrophilic surface of biosensors on droplet manipulation.

    Science.gov (United States)

    Samiei, Ehsan; Luka, George S; Najjaran, Homayoun; Hoorfar, Mina

    2016-07-15

    Several studies have been performed on the integration of biosensors into digital microfluidics (DMF). Despite the general success in their detection capabilities, there are still two challenges associated with the integration of biosensors into DMF: (1) complete removal of the droplet containing the analytes from the sensing surface; and (2) biochemical regeneration of the biosensor involving detaching the target analyte from the receptor after each round of sensing. The latter is case dependent and the solution can vary from one application to another. Our research aims at addressing the former, the solution to which is applicable to all biosensors integrated to DMF. This paper presents a thorough characterization of the hydrophilic surface of the biosensor in terms of wettability and geometry, taking into account the overall configuration of the DMF platform. Consequently, we identify the optimal geometry of the sensing surface and the DMF platform providing successful removal of the target droplet from the sensing surface after detection. Based on the results, the gap height is suggested to be chosen at the upper limit of the applicable range. Also, the biosensor, patterned on the device top plate, is recommended to be designed with a high aspect ratio and aligned with the center of the actuating electrode. As a proof of concept, the optimum configuration is implemented on a DMF platform with an interdigitated capacitive biosensor to detect different concentrations of Cryptosporidium, for which it is shown that the sample droplet is removed successfully from the superhydrophilic surface of the biosensor. PMID:27016626

  12. Design strategies of alarm system for SMART

    International Nuclear Information System (INIS)

    The high level goal of the SMART-AS (Alarm System for System-integrated Modular Advanced ReacTor) is for operators to enthusiastically accept a new technology that will improve their response to alarms during plant transient conditions. Three alarm system design characteristics were included: (1) alarm processing (degree of alarm reduction); (2) alarm availability (prioritization and suppression); and (3) alarm display (a dedicated tile format, a mixed tile and message list format, and a format in which alarm information is integrated into the process displays). The SMART-AS prioritizes alarms based on the state of the plant; reduces the amount of information presented to the operator by grouping and display the arms in accordance with the present state of the plant; and allows nuisance alarms to be suppressed. This paper provides an introduction into applying the data mining techniques for the alarm processing of SMART-AS. In this paper, we describe our data mining algorithms, and illustrate how to apply these algorithms to generate an alarm suppression model from the alarm data. (authors)

  13. Fire auto alarm system intelligent trend

    International Nuclear Information System (INIS)

    The author gives the course and trend of the fire alarm system going to more computerized and more intelligent. It is described that only the system applied artificial intelligent and confusion control is the true intelligent fire alarm system. The author gives the detailed analysis on the signal treatment of artificial intelligent applied to analogue fire alarm system as well as the alarm system controlled by confusion technology and artificial nervous net

  14. 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. PMID:27365040

  15. 10 CFR 74.57 - Alarm resolution.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Alarm resolution. 74.57 Section 74.57 Energy NUCLEAR... Quantities of Strategic Special Nuclear Material § 74.57 Alarm resolution. (a) Licensees subject to § 74.51 shall provide the MC&A alarm resolution capabilities described in paragraphs (b) through (f) of...

  16. SUBSURFACE VISUAL ALARM SYSTEM ANALYSIS

    International Nuclear Information System (INIS)

    The ''Subsurface Fire Hazard Analysis'' (CRWMS M andO 1998, page 61), and the document, ''Title III Evaluation Report for the Surface and Subsurface Communication System'', (CRWMS M andO 1999a, pages 21 and 23), both indicate the installed communication system is adequate to support Exploratory Studies Facility (ESF) activities with the exception of the mine phone system for emergency notification purposes. They recommend the installation of a visual alarm system to supplement the page/party phone system The purpose of this analysis is to identify data communication highway design approaches, and provide justification for the selected or recommended alternatives for the data communication of the subsurface visual alarm system. This analysis is being prepared to document a basis for the design selection of the data communication method. This analysis will briefly describe existing data or voice communication or monitoring systems within the ESF, and look at how these may be revised or adapted to support the needed data highway of the subsurface visual alarm. system. The existing PLC communication system installed in subsurface is providing data communication for alcove No.5 ventilation fans, south portal ventilation fans, bulkhead doors and generator monitoring system. It is given that the data communication of the subsurface visual alarm system will be a digital based system. It is also given that it is most feasible to take advantage of existing systems and equipment and not consider an entirely new data communication system design and installation. The scope and primary objectives of this analysis are to: (1) Briefly review and describe existing available data communication highways or systems within the ESF. (2) Examine technical characteristics of an existing system to disqualify a design alternative is paramount in minimizing the number of and depth of a system review. (3) Apply general engineering design practices or criteria such as relative cost, and degree

  17. Applications of Nanomaterials in Electrogenerated Chemiluminescence Biosensors

    Directory of Open Access Journals (Sweden)

    Honglan Qi

    2009-01-01

    Full Text Available Electrogenerated chemiluminescence (also called electrochemiluminescence and abbreviated ECL involves the generation of species at electrode surfaces that then undergo electron-transfer reactions to form excited states that emit light. ECL biosensor, combining advantages offered by the selectivity of the biological recognition elements and the sensitivity of ECL technique, is a powerful device for ultrasensitive biomolecule detection and quantification. Nanomaterials are of considerable interest in the biosensor field owing to their unique physical and chemical properties, which have led to novel biosensors that have exhibited high sensitivity and stability. Nanomaterials including nanoparticles and nanotubes, prepared from metals, semiconductor, carbon or polymeric species, have been widely investigated for their ability to enhance the efficiencies of ECL biosensors, such as taking as modification electrode materials, or as carrier of ECL labels and ECL-emitting species. Particularly useful application of nanomaterials in ECL biosensors with emphasis on the years 2004-2008 is reviewed. Remarks on application of nanomaterials in ECL biosensors are also surveyed.

  18. Alarm-Processing in Nuclear Power Plants

    International Nuclear Information System (INIS)

    Information overload due to the activation of a great number of alarms in a short time is a common problem for the operator in the control room of a industrial plant, mainly in complex process like the nuclear power plants.The problem is the conventional conception of the alarm system, that defines each alarm like a separated and independent entity of the global situation of the plant.A direct consequence is the generation of multiple alarms during a significative disturbance in the process, being most of them redundant and irrelevant to the actual process state wich involves an extra load to the operator, who wastes time in acting selecting the important alarms of the group that appears or lead to a an erroneous action.The present work first describes the techniques developed in the last years to attack the avalanche of alarms problem.Later we present our approach to alarm-processing: an expert system as alarm-filter.Our objective is collect in the system the state of the art in the development of advanced alarm systems, offering an improvement of the information flow to the operators through the suppression of nonsignificant alarms and a structured visualization of the process state.Such support is important during a disturbance for the identification of plant state, diagnosis, consequence prediction and corrective actions.The system is arranged in three stages: alarm-generation, alarm-filter and alarm-presentation.The alarm-generation uses conventional techniques or receives them from an external system.The alarm-filter uses suppression techniques based on: irrelevance analysis with the operation mode and the state of components, causal reasoning and static importance analysis.The alarm presentation is made through a structured way using a priority scheme with three level.The knowledge representation of each alarm is based on frames and a graph of alarms for global knowledge, where the connections between nodes represent causal and irrelevance relations

  19. Development and implementation of miniature impedimetric systems for biosensor readout

    OpenAIRE

    BROEDERS, Jeroen

    2013-01-01

    Research in the field of biosensors, i.e. sensors that are based on a biological recognition layer, has steadily increased in popularity over the last few decades. Sensors suited for a wide variety of bio-medically relevant target molecules are constantly being developed. The number of biosensor devices that actually reach the commercial market is however highly limited. Very few examples of such devices can be found, aside from the well-known glucose sensor and pregnancy test strips. Recent ...

  20. Alarming Rise In Birth Defects

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A rapid rise in birth defects has prompted China to look for causes and solutionsEvery 60 seconds two children are born in China with a handicap.It’s an alarming fact,but one that young adults across the country who hope to have children face every day. At a conference on the prevention of birth defects in Chengdu of Sichuan Province in September,Vice Minister of the National Population and Family Planning Commission Jiang Fan revealed this inconvenient truth, supported by shocking statistics.

  1. Video systems for alarm assessment

    International Nuclear Information System (INIS)

    The purpose of this NUREG is to present technical information that should be useful to NRC licensees in designing closed-circuit television systems for video alarm assessment. There is a section on each of the major components in a video system: camera, lens, lighting, transmission, synchronization, switcher, monitor, and recorder. Each section includes information on component selection, procurement, installation, test, and maintenance. Considerations for system integration of the components are contained in each section. System emphasis is focused on perimeter intrusion detection and assessment systems. A glossary of video terms is included. 13 figs., 9 tabs

  2. Biosensors for termite control

    Science.gov (United States)

    Farkhanda, M.

    2013-12-01

    Termites are major urban pests in Pakistan and cause damage to wooden structures and buildings. Termite management has two parts: prevention and control. The most difficult part of termite control is termite detection as most of them are subterranean in Pakistan and have tunneling habit.Throughout the world, chemical termiticides are going to be replaced by baits, microwave and sensor technology. Termite species are distinct biologically and have specific foraging behaviors. Termite Detection Radar, Moisture meter and Remote Thermal Sensor with Laser are available throughout the world. These can detect termites underground and use fewer chemicals than traditional methods. For wooden buildings, a termite sensor and an intrusion detection system for detecting termites are designed. A pair of electrodes is disposed inside the container. A pair of terminals is connected to these electrodes, these extend outside the container. Termites are detected by a change of conductivity between the electrodes, when termites are detected a warning device generates a warning signal. In Pakistan, there is dire need to develop such biosensoring devices locally, then apply control methods that would save money and protect the environment.

  3. Biosensors for termite control

    International Nuclear Information System (INIS)

    Termites are major urban pests in Pakistan and cause damage to wooden structures and buildings. Termite management has two parts: prevention and control. The most difficult part of termite control is termite detection as most of them are subterranean in Pakistan and have tunneling habit.Throughout the world, chemical termiticides are going to be replaced by baits, microwave and sensor technology. Termite species are distinct biologically and have specific foraging behaviors. Termite Detection Radar, Moisture meter and Remote Thermal Sensor with Laser are available throughout the world. These can detect termites underground and use fewer chemicals than traditional methods. For wooden buildings, a termite sensor and an intrusion detection system for detecting termites are designed. A pair of electrodes is disposed inside the container. A pair of terminals is connected to these electrodes, these extend outside the container. Termites are detected by a change of conductivity between the electrodes, when termites are detected a warning device generates a warning signal. In Pakistan, there is dire need to develop such biosensoring devices locally, then apply control methods that would save money and protect the environment

  4. Alarm management for storage and transportation terminals; Gerenciamento de alarmes para terminais de transferencia e estocagem

    Energy Technology Data Exchange (ETDEWEB)

    Loureiro, Patricia [PETROBRAS, Rio de Janeiro, RJ (Brazil); Feldman, Rafael Noac [PETROBRAS Transporte S.A. (TRANSPETRO), Rio de Janeiro, RJ (Brazil)

    2005-07-01

    Recently, in many industrial segments, it has been taken into account the issues related to the high amount of alarms that are announced in the control rooms, even if the industrial process is under normal conditions. Recent studies and surveys have shown that the three major problems related to it are: alarms that remain active during normal operation; alarms that remain chattering during an operational period; the phenomenon called Alarm flood, that occurs when an extensive amount of alarms is announced and the operator does not have enough time to take effective actions. In order to reduce or to eliminate the two above mentioned causes, alarm analysis and housekeeping, called Alarm Rationalization, have been efficient in major cases, because such facts occur mainly due to inadequate limits definition and/or equipment and instruments out of service or in maintenance. Such alarms are called in the literature as bad-actors or villains, and their occurrences may reach up to 50% of the daily total amount of alarms. This paper aims to present the main results of a project named Alarm Management for Transfer and Storage Terminals. The project development is based on two different terminal surveys, in order not only to identify the most frequent causes of undesirable alarms, but also to generate design standards. The main phases of the project are: alarm rationalization based on bad-actors detection; generate a set of design and operation standards; generate an Alarm Philosophy document for the Terminals. (author)

  5. 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...

  6. Silicon Photonic Biosensors for Lab-on-a-Chip Applications

    Directory of Open Access Journals (Sweden)

    Laura M. Lechuga

    2008-06-01

    Full Text Available In the last two decades, we have witnessed a remarkable progress in the development of biosensor devices and their application in areas such as environmental monitoring, biotechnology, medical diagnostics, drug screening, food safety, and security, among others. The technology of optical biosensors has reached a high degree of maturity and several commercial products are on the market. But problems of stability, sensitivity, and size have prevented the general use of optical biosensors for real field applications. Integrated photonic biosensors based on silicon technology could solve such drawbacks, offering early diagnostic tools with better sensitivity, specificity, and reliability, which could improve the effectiveness of in-vivo and in-vitro diagnostics. Our last developments in silicon photonic biosensors will be showed, mainly related to the development of portable and highly sensitive integrated photonic sensing platforms.

  7. Biosensors for environmental monitoring of endocrine disruptors: a review article

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Mozaz, Sara; Lopez de Alda, Maria J.; Barcelo, Damia [Department of Environmental Chemistry, IIQAB-CSIC, C/ Jordi Girona 18-26, 08034, Barcelona (Spain); Marco, Maria-Pilar [Department of Biological Organic Chemistry, IIQAB-CSIC, C/ Jordi Girona 18-26, 08034, Barcelona (Spain)

    2004-02-01

    This article provides an overview of the applications of biosensors in analysis and monitoring of endocrine-disrupting compounds (EDCs) in the environment. Special attention is devoted to the various types of physical-chemical signal transduction elements, biological mechanisms employed as sensing elements and techniques used for immobilisation of the bioreceptor molecules on the transducer surface. Two different classes of biosensors for EDCs are considered: biosensors that measure endocrine-disrupting effects, and biosensors that respond to the presence of a specific substance (or group of substances) based on the specific recognition of a biomolecule. Several examples of them are presented to illustrate the power of the biosensor technology for environmental applications. Future trends in the development of new, more advanced devices are also outlined. (orig.)

  8. TMACS test procedure TP001: Alarm management. Revision 6

    International Nuclear Information System (INIS)

    The TMACS Software Project Test Procedures translate the project's acceptance criteria into test steps. Software releases are certified when the affected Test Procedures are successfully performed and the customers authorize installation of these changes. This Test Procedure addresses the Alarm Management requirements of the TMACS. The features to be tested are: real-time alarming on high and low level and discrete alarms, equipment alarms, dead-band filtering, alarm display color coding, alarm acknowledgement, and alarm logging

  9. Research and development of a miniaturized and high-throughput SPR biosensor device%一种小型高通量SPR生物传感检测装置的研制

    Institute of Scientific and Technical Information of China (English)

    杨军; 黄小玲; 张丽果; 曹毅; 杨静

    2011-01-01

    针对一种角度扫描型SPR生物传感检测装置的小型化、高通量研究,包括系统的硬、软件研制及实验测试.在现有 SPR传感研究基础上,提出了实现仪器小型化的设计方案,可以在仪器体积明显减小的情况下,保持检测精度基本不变.同时,利用入射光分束,靶标阵列,以及相应的阵列图像采集、处理及分析方法,实现了多样品的同时检测分析.针对新的系统设计,利用计算仿真确定了相应的实验参数.在新建立的SPR检测装置上完成了不同金膜厚度及芯片表面修饰后的共振曲线检测,并实现了C反应蛋白的检测分析.结果表明,该系统能够有效地分析表面介质特性改变所引起的共振角度变化,同时,设备的 小型化和高通量基本实现.%The research and development of a miniaturized, high-throughput angle-scanning SPR biosensor device. Based on the existing SPR research, a new device design was brought forward in order to keep the detection precision while obviously miniaturize the size of the device. Meanwhile, multiple light beam, target molecule array and image processing methods were used to detect multiple samples. Computer simulation was used to determine the related design parameters. SPR curves of gold film with different thickness and different surface modification were detected using this prototype device. Test results indicate that the developed new device can effectively analyze the change of resonance angle due to the change of surface medium characteristics. At the same time, the miniaturization and high-throughput analysis of the device are basically realized.

  10. False alarm reduction in critical care.

    Science.gov (United States)

    Clifford, Gari D; Silva, Ikaro; Moody, Benjamin; Li, Qiao; Kella, Danesh; Chahin, Abdullah; Kooistra, Tristan; Perry, Diane; Mark, Roger G

    2016-08-01

    High false alarm rates in the ICU decrease quality of care by slowing staff response times while increasing patient delirium through noise pollution. The 2015 PhysioNet/Computing in Cardiology Challenge provides a set of 1250 multi-parameter ICU data segments associated with critical arrhythmia alarms, and challenges the general research community to address the issue of false alarm suppression using all available signals. Each data segment was 5 minutes long (for real time analysis), ending at the time of the alarm. For retrospective analysis, we provided a further 30 seconds of data after the alarm was triggered. A total of 750 data segments were made available for training and 500 were held back for testing. Each alarm was reviewed by expert annotators, at least two of whom agreed that the alarm was either true or false. Challenge participants were invited to submit a complete, working algorithm to distinguish true from false alarms, and received a score based on their program's performance on the hidden test set. This score was based on the percentage of alarms correct, but with a penalty that weights the suppression of true alarms five times more heavily than acceptance of false alarms. We provided three example entries based on well-known, open source signal processing algorithms, to serve as a basis for comparison and as a starting point for participants to develop their own code. A total of 38 teams submitted a total of 215 entries in this year's Challenge. This editorial reviews the background issues for this challenge, the design of the challenge itself, the key achievements, and the follow-up research generated as a result of the Challenge, published in the concurrent special issue of Physiological Measurement. Additionally we make some recommendations for future changes in the field of patient monitoring as a result of the Challenge. PMID:27454172

  11. Knowledge Discovery from Communication Network Alarm Databases

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The technique of Knowledge Discovery in Databases(KDD) to learn valuable knowledge hidden in network alarm databases is introduced. To get such knowledge, we propose an efficient method based on sliding windows (named as Slidwin) to discover different episode rules from time sequential alarm data. The experimental results show that given different thresholds parameters, large amount of different rules could be discovered quickly.

  12. 46 CFR 130.450 - Machinery alarms.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Machinery alarms. 130.450 Section 130.450 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS VESSEL CONTROL, AND MISCELLANEOUS EQUIPMENT AND SYSTEMS Automation of Unattended Machinery Spaces § 130.450 Machinery alarms....

  13. Implantable electronic medical devices

    CERN Document Server

    Fitzpatrick, Dennis

    2014-01-01

    Implantable Electronic Medical Devices provides a thorough review of the application of implantable devices, illustrating the techniques currently being used together with overviews of the latest commercially available medical devices. This book provides an overview of the design of medical devices and is a reference on existing medical devices. The book groups devices with similar functionality into distinct chapters, looking at the latest design ideas and techniques in each area, including retinal implants, glucose biosensors, cochlear implants, pacemakers, electrical stimulation t

  14. From alarm systems to smart houses.

    Science.gov (United States)

    Vlaskamp, F J

    1992-01-01

    The percentage of senior citizens in the Netherlands will rise in coming years. The expected percentage for the year 2010 of persons over age 65 in the total population is 15%. More persons over age 65 than ever before will continue to live in their own environment. Emergency response systems (ERS) can support independent living. The most common type of organization distributing ERS is a small, partly subsidized local alarm organization run by a social welfare office for the elderly. Government subsidy has been reduced in recent years which has motivated small organizations to join together into larger regional organizations in order to get a more solid financial base. On the other hand new semi-commercial and commercial organizations have come into being. These developments are part of the growing importance of home care, leading to more medical applications of ERS. User satisfaction with ERS is high. Portable triggers can enhance the effectiveness of the system. However, many users do not wear the portable trigger when feeling well. Future technical developments will result in multifunctionality of ERS-devices. In the long term the hardware of today will be integrated in a multimedia home terminal replacing the telephone. The portable trigger will remain the only specific hardware at home for ERS. PMID:10126436

  15. Design of voice alarm device for automobile handbrake misuse and overspeed based on MCU%基于单片机的汽车手刹使用不当和超速语音提示装置的设计

    Institute of Scientific and Technical Information of China (English)

    贾萍; 梁文鑫

    2012-01-01

    以STC89C52单片机为核心,综合运用霍尔传感、热释电红外传感、无线传输、数字语音等技术,设计了汽车手刹使用不当和超速行驶语音提示装置.该装置增加了无线发射接收模块编码加载道路限速标准,实现了对汽车的智能限速提示,且安装简单、易于实现.%Voice alarm device for misuse of automobile handbrake and overspeed driving were designed. The device comprehensively applied technologies with Holzer sensing, pyroelectric infrared sensor, wireless transmission and digital voice and so on with STC89C52 MCU as the core, thus increasing standards for speed limit to loading road of wireless transmitting and receiving module code and achieving smart prompt to speed limit of automobile, which was characterized by simple installation and easy realization.

  16. Applications of Nanomaterials in Electrochemical Enzyme Biosensors

    Directory of Open Access Journals (Sweden)

    Xiaodi Yang

    2009-10-01

    Full Text Available A biosensor is defined as a kind of analytical device incorporating a biological material, a biologically derived material or a biomimic intimately associated with or integrated within a physicochemical transducer or transducing microsystem. Electrochemical biosensors incorporating enzymes with nanomaterials, which combine the recognition and catalytic properties of enzymes with the electronic properties of various nanomaterials, are new materials with synergistic properties originating from the components of the hybrid composites. Therefore, these systems have excellent prospects for interfacing biological recognition events through electronic signal transduction so as to design a new generation of bioelectronic devices with high sensitivity and stability. In this review, we describe approaches that involve nanomaterials in direct electrochemistry of redox proteins, especially our work on biosensor design immobilizing glucose oxidase (GOD, horseradish peroxidase (HRP, cytochrome P450 (CYP2B6, hemoglobin (Hb, glutamate dehydrogenase (GDH and lactate dehydrogenase (LDH. The topics of the present review are the different functions of nanomaterials based on modification of electrode materials, as well as applications of electrochemical enzyme biosensors.

  17. Wallac automatic alarm dosimeter type RAD21

    International Nuclear Information System (INIS)

    The Automatic Alarm Dosimeter type RAD 21 is a batterypowered personal dosemeter and exposure rate alarm monitor, designed to be worn on the body, covering an exposure range from 0.1 to 999.9 mR and has an audible alarm which can be pre-set over the range 1 mR h-1 to 250 mR h-1. The instrument is designed to measure x- and γ radiation over the energy range 50 keV to 3 MeV. The facilities and controls, the radiation, electrical, environmental and mechanical characteristics, and the manual, have been evaluated. (U.K.)

  18. Alarm points for fixed oxygen monitors

    International Nuclear Information System (INIS)

    Oxygen concentration monitors were installed in a vault where numerous pipes carried inert cryogens and gases to the Mirror Fusion Test Facility (MFTF-B) experimental vessel at Lawrence Livermore National Laboratory (LLNL). The problems associated with oxygen-monitoring systems and the reasons why such monitors were installed were reviewed. As a result of this review, the MFTF-B monitors were set to sound an evacuation alarm when the oxygen concentration fell below 18%. We chose the 18% alarm criterion to minimize false alarms and to allow time for personnel to escape in an oxygen-deficient environment

  19. User experience network. Supply gas failure alarm on Cardinal Health Infant Flow SiPAP units may not activate.

    Science.gov (United States)

    2009-07-01

    The supply gas failure alarm on Cardinal Health Infant Flow SiPAP units manufactured before April 2009 may not activate in the event of a gas supply loss if the device's silencer accessory is attached. However, the unit's FiO2 (fraction of inspired oxygen) and low-airway-pressure alarms will activate in such cases. If both of these alarms activate simultaneously, users should suspect a failure of the gas supply pressure. Identifying affected units requires testing that can be conducted during the device's next scheduled maintenance.

  20. Biosensors Incorporating Bimetallic Nanoparticles

    Directory of Open Access Journals (Sweden)

    John Rick

    2015-12-01

    Full Text Available This article presents a review of electrochemical bio-sensing for target analytes based on the use of electrocatalytic bimetallic nanoparticles (NPs, which can improve both the sensitivity and selectivity of biosensors. The review moves quickly from an introduction to the field of bio-sensing, to the importance of biosensors in today’s society, the nature of the electrochemical methods employed and the attendant problems encountered. The role of electrocatalysts is introduced with reference to the three generations of biosensors. The contributions made by previous workers using bimetallic constructs, grouped by target analyte, are then examined in detail; following which, the synthesis and characterization of the catalytic particles is examined prior to a summary of the current state of endeavor. Finally, some perspectives for the future of bimetallic NPs in biosensors are given.

  1. Recommendations for the LHC safety alarm system

    CERN Document Server

    Laeger, H

    1999-01-01

    A working group was set up to define the LHC safety alarm system, also known as Alarm-of-Level-3-System (AL3S). The mandate asked for recommendations to be elaborated on four items: the overall concept of the AL3S for machine and experiments, the transmission and display of safety alarms, the AL3S during civil engineering construction, and the transition from the present LEP to the final LHC safety alarm system. The members of the working group represented a wide range of interest and experience including the CERN Fire Brigade, safety officers from experiments and machines, and specialists for safety and control systems. The recommendations highlight the need for a clear definition of responsibilities and procedures, well-engineered homogeneous systems across CERN, and they point to several important issues outside the mandate of the working group. These recommendations were presented, discussed and accepted by several CERN and LHC committees.

  2. A NEW INVENTION OF ALARM REMINDER LOCKING (ARL SECURITY SYSTEM

    Directory of Open Access Journals (Sweden)

    M.S.M. Effendi

    2016-02-01

    Full Text Available Alarm Reminder Locking (ARL Security System mainly focuses on a door security system, which can install in the door area to increase the security level for home, office room, hostel or other places. This system used Arduino Controller and Global System for Mobile Communication (GSM technology, which is the cheapest source to embed the security system to transmit the Short Message Service (SMS alert data. This device integrates three functions that are alarming, reminder and locked for a purpose of safety and connecting via mobile phone to remind the users through SMS. This device has a 3 modes of operation which is the system will be functional when the door is not improperly closed for the first reminder with the buzzer alert. The second mode is automated locked will be activated when users closed the door, but did not lock manually. Intrusion mode will activate while auto locked modes are interrupted without proper access. All this integrated system will provide high security access against intrusion occurrence. This security device will bring a new benefit to the user to consider about the userfriendly application, low power consumption and reasonable cost to install.

  3. Cantilever-Based Biosensors in CMOS Technology

    CERN Document Server

    Kirstein, K -U; Zimmermann, M; Vancura, C; Volden, T; Song, W H; Lichtenberg, J; Hierlemannn, A

    2011-01-01

    Single-chip CMOS-based biosensors that feature microcantilevers as transducer elements are presented. The cantilevers are functionalized for the capturing of specific analytes, e.g., proteins or DNA. The binding of the analyte changes the mechanical properties of the cantilevers such as surface stress and resonant frequency, which can be detected by an integrated Wheatstone bridge. The monolithic integrated readout allows for a high signal-to-noise ratio, lowers the sensitivity to external interference and enables autonomous device operation.

  4. Nanobiocatalysts for biofuel cells and biosensor systems

    Directory of Open Access Journals (Sweden)

    Radivoje M. Prodanović

    2011-10-01

    Full Text Available This overview summarizes the application of enzymes in the manufacture and design of biofuel cells and biosensors. The emphasis will be put on the protein engineering techniques used for improving the properties of enzymes such as nanobiocatalysts, e.g. immobilization orientation, stability, activity and efficiency of electron transfer between immobilized enzymes and electrodes. Some possible applications in the military and some future designs of these electric devices will be discussed as well.

  5. 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.

  6. Paper electrodes for bioelectrochemistry: Biosensors and biofuel cells.

    Science.gov (United States)

    Desmet, Cloé; Marquette, Christophe A; Blum, Loïc J; Doumèche, Bastien

    2016-02-15

    Paper-based analytical devices (PAD) emerge in the scientific community since 2007 as low-cost, wearable and disposable devices for point-of-care diagnostic due to the widespread availability, long-time knowledge and easy manufacturing of cellulose. Rapidly, electrodes were introduced in PAD for electrochemical measurements. Together with biological components, a new generation of electrochemical biosensors was born. This review aims to take an inventory of existing electrochemical paper-based biosensors and biofuel cells and to identify, at the light of newly acquired data, suitable methodologies and crucial parameters in this field. Paper selection, electrode material, hydrophobization of cellulose, dedicated electrochemical devices and electrode configuration in biosensors and biofuel cells will be discussed.

  7. Glucose Biosensors: An Overview of Use in Clinical Practice

    Directory of Open Access Journals (Sweden)

    Eun-Hyung Yoo

    2010-05-01

    Full Text Available Blood glucose monitoring has been established as a valuable tool in the management of diabetes. Since maintaining normal blood glucose levels is recommended, a series of suitable glucose biosensors have been developed. During the last 50 years, glucose biosensor technology including point-of-care devices, continuous glucose monitoring systems and noninvasive glucose monitoring systems has been significantly improved. However, there continues to be several challenges related to the achievement of accurate and reliable glucose monitoring. Further technical improvements in glucose biosensors, standardization of the analytical goals for their performance, and continuously assessing and training lay users are required. This article reviews the brief history, basic principles, analytical performance, and the present status of glucose biosensors in the clinical practice.

  8. Engineered PQQ-Glucose Dehydrogenase as a Universal Biosensor Platform.

    Science.gov (United States)

    Guo, Zhong; Murphy, Lindy; Stein, Viktor; Johnston, Wayne A; Alcala-Perez, Siro; Alexandrov, Kirill

    2016-08-17

    Biosensors with direct electron output hold promise for nearly seamless integration with portable electronic devices. However, so far, they have been based on naturally occurring enzymes that significantly limit the spectrum of detectable analytes. Here, we present a novel biosensor architecture based on analyte-driven intermolecular recombination and activity reconstitution of a re-engineered component of glucometers: PQQ-glucose dehydrogenase. We demonstrate that this sensor architecture can be rapidly adopted for the detection of immunosuppressant drugs, α-amylase protein, or protease activity of thrombin and Factor Xa. The biosensors could be stored in dried form without appreciable loss of activity. We further show that ligand-induced activity of the developed biosensors could be directly monitored by chronoamperometry, enabling construction of disposable sensory electrodes. We expect that this architecture could be expanded to the detection of other biochemical activities, post-translational modifications, nucleic acids, and inorganic molecules. PMID:27463000

  9. Design architecture of double spiral interdigitated electrode with back gate electrode for biosensor application

    Science.gov (United States)

    Fathil, M. F. M.; Arshad, M. K. Md.; Hashim, U.; Ruslinda, A. R.; Gopinath, Subash C. B.; M. Nuzaihan M., N.; Ayub, R. M.; Adzhri, R.; Zaki, M.; Azman, A. H.

    2016-07-01

    This paper presents the preparation method of photolithography chrome mask design used in fabrication process of double spiral interdigitated electrode with back gate biasing based biosensor. By learning the fabrication process flow of the biosensor, the chrome masks are designed through drawing using the AutoCAD software. The overall width and length of the device is optimized at 7.0 mm and 10.0 mm, respectively. Fabrication processes of the biosensor required three chrome masks, which included back gate opening, spiral IDE formation, and passivation area formation. The complete chrome masks design will be sent for chrome mask fabrication and for future use in biosensor fabrication.

  10. 46 CFR 108.627 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide alarm. 108.627 Section 108.627 Shipping... EQUIPMENT Equipment Markings and Instructions § 108.627 Carbon dioxide alarm. Each carbon dioxide alarm must be identified by marking: “WHEN ALARM SOUNDS VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED” next...

  11. 46 CFR 78.47-9 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Carbon dioxide alarm. 78.47-9 Section 78.47-9 Shipping... and Emergency Equipment, Etc. § 78.47-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.” (b)...

  12. 46 CFR 169.732 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide alarm. 169.732 Section 169.732 Shipping... Control, Miscellaneous Systems, and Equipment Markings § 169.732 Carbon dioxide alarm. Each carbon dioxide alarm must be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.”...

  13. 46 CFR 97.37-9 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide alarm. 97.37-9 Section 97.37-9 Shipping... Markings for Fire and Emergency Equipment, Etc. § 97.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE...

  14. 46 CFR 196.37-9 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide alarm. 196.37-9 Section 196.37-9 Shipping... Markings for Fire and Emergency Equipment, etc. § 196.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE...

  15. System for alarms analysis and optimization in petrochemicals plants; Sistema para analise e otimizacao de alarmes em plantas petroquimicas

    Energy Technology Data Exchange (ETDEWEB)

    Leitao, Gustavo; Pifer, Aderson; Guedes, Luiz Affonso [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Saito, Kaku; Aquino, Leonardo [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2008-07-01

    The present work presents a group of algorithms, techniques and functionalities on alarms management which can be used efficiently on the treatment of 'disturbances' caused by the informal management of the alarm systems. Among the disturbances handled by these techniques, there is the recognition of intermittent alarms and false alarms, location of alarm floods and correlation between alarms, aiming the identification of communal root causes. The results will be presented through a case study on petrochemical alarm plants. At last, the results obtained by the utilization of such functionalities will be presented and discussed. (author)

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

    International Nuclear Information System (INIS)

    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

  17. Cultured neuronal networks as environmental biosensors.

    Science.gov (United States)

    O'Shaughnessy, Thomas J; Gray, Samuel A; Pancrazio, Joseph J

    2004-01-01

    Contamination of water by toxins, either intentionally or unintentionally, is a growing concern for both military and civilian agencies and thus there is a need for systems capable of monitoring a wide range of natural and industrial toxicants. The EILATox-Oregon Workshop held in September 2002 provided an opportunity to test the capabilities of a prototype neuronal network-based biosensor with unknown contaminants in water samples. The biosensor is a portable device capable of recording the action potential activity from a network of mammalian neurons grown on glass microelectrode arrays. Changes in the action potential fi ring rate across the network are monitored to determine exposure to toxicants. A series of three neuronal networks derived from mice was used to test seven unknown samples. Two of these unknowns later were revealed to be blanks, to which the neuronal networks did not respond. Of the five remaining unknowns, a significant change in network activity was detected for four of the compounds at concentrations below a lethal level for humans: mercuric chloride, sodium arsenite, phosdrin and chlordimeform. These compounds--two heavy metals, an organophosphate and an insecticide--demonstrate the breadth of detection possible with neuronal networks. The results generated at the workshop show the promise of the neuronal network biosensor as an environmental detector but there is still considerable effort needed to produce a device suitable for routine environmental threat monitoring. PMID:15478174

  18. Design & fabrication of cantilever array biosensors

    Directory of Open Access Journals (Sweden)

    Anja Boisen

    2009-09-01

    Full Text Available 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 of samples. Currently available fabrication technology will allow the integration of electronic readout and sample introduction into a single unit, decreasing the device size, detection time, and cost. Biosensing technologies based on microfabricated cantilever arrays involving multiple cantilevers, 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.

  19. 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...

  20. Microbial fuel cells for biosensor applications.

    Science.gov (United States)

    Yang, Huijia; Zhou, Minghua; Liu, Mengmeng; Yang, Weilu; Gu, Tingyue

    2015-12-01

    Microbial fuel cells (MFCs) face major hurdles for real-world applications as power generators with the exception of powering small sensor devices. Despite tremendous improvements made in the last two decades, MFCs are still too expensive to build and operate and their power output is still too small. In view of this, in recently years, intensive researches have been carried out to expand the applications into other areas such as acid and alkali production, bioremediation of aquatic sediments, desalination and biosensors. Unlike power applications, MFC sensors have the immediate prospect to be practical. This review covers the latest developments in various proposed biosensor applications using MFCs including monitoring microbial activity, testing biochemical oxygen demand, detection of toxicants and detection of microbial biofilms that cause biocorrosion.

  1. A revival of the alarm system: Making the alarm list useful during incidents

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, J. E.; Oehman, B.; Calzada, A. [GoalArt, Scheelevaegen 17, 223 70 Lund (Sweden); Nihlwing, C.; Jokstad, H.; Kristianssen, L. I.; Kvalem, J. [IFE, OS alle 13, 1777 Halden (Norway); Lind, M. [Oested-DTU, Technical Univ. of Denmark, DK-2800, Kongens Lyngby (Denmark)

    2006-07-01

    In control rooms there are often problems with information overload, which means that the operators may receive more information than they are able to interpret. The most serious information overload occurs in two types of situations. The first is when the operating state of the plant changes, which often gives raise to a shower of alarms and events. Such an alarm shower is expected, but can be dangerous, because it may hide other alarms originating from unrelated faults. The second problem occurs when a fault causes several consequential faults, leading to a so-called alarm cascade. Because the alarms seldom arrive in correct time order, it can be very difficult to analyze such a cascade, and the information overload occurs in exactly the moment when a potentially dangerous situation starts. In an ongoing project, GoalArt and IFE are cooperating in testing and evaluating GoalArt's methods for alarm reduction and root cause analysis. The testing comprises two specific algorithms, root cause analysis and state-based alarm priority. The GoalArt system has been integrated with the HAMBO simulator so that operators can evaluate the algorithms on-line. (authors)

  2. Attitude of resident doctors towards intensive care units′ alarm settings

    Directory of Open Access Journals (Sweden)

    Rakesh Garg

    2010-01-01

    Full Text Available Intensive care unit (ICU monitors have alarm options to intimate the staff of critical incidents but these alarms needs to be adjusted in every patient. With this objective in mind, this study was done among resident doctors, with the aim of assessing the existing attitude among resident doctors towards ICU alarm settings. This study was conducted among residents working at ICU of a multispeciality centre, with the help of a printed questionnaire. The study involved 80 residents. All residents were in full agreement on routine use of ECG, pulse oximeter, capnograph and NIBP monitoring. 86% residents realised the necessity of monitoring oxygen concentration, apnoea monitoring and expired minute ventilation monitoring. 87% PGs and 70% SRs routinely checked alarm limits for various parameters. 50% PGs and 46.6% SRs set these alarm limits. The initial response to an alarm among all the residents was to disable the alarm temporarily and try to look for a cause. 92% of PGs and 98% of SRs were aware of alarms priority and colour coding. 55% residents believed that the alarm occurred due to patient disturbance, 15% believed that alarm was due to technical problem with monitor/sensor and 30% thought it was truly related to patient′s clinical status. 82% residents set the alarms by themselves, 10% believed that alarms should be adjusted by nurse, 4% believed the technical staff should take responsibility of setting alarm limits and 4% believed that alarm levels should be pre-adjusted by the manufacturer. We conclude that although alarms are an important, indispensable, and lifesaving feature, they can be a nuisance and can compromise quality and safety of care by frequent false positive alarms. We should be familiar of the alarm modes, check and reset the alarm settings at regular interval or after a change in clinical status of the patient.

  3. Attitude of resident doctors towards intensive care units' alarm settings.

    Science.gov (United States)

    Garg, Rakesh; Bhalotra, Anju R; Goel, Nitesh; Pruthi, Amit; Bhadoria, Poonam; Anand, Raktima

    2010-11-01

    Intensive care unit (ICU) monitors have alarm options to intimate the staff of critical incidents but these alarms needs to be adjusted in every patient. With this objective in mind, this study was done among resident doctors, with the aim of assessing the existing attitude among resident doctors towards ICU alarm settings. This study was conducted among residents working at ICU of a multispeciality centre, with the help of a printed questionnaire. The study involved 80 residents. All residents were in full agreement on routine use of ECG, pulse oximeter, capnograph and NIBP monitoring. 86% residents realised the necessity of monitoring oxygen concentration, apnoea monitoring and expired minute ventilation monitoring. 87% PGs and 70% SRs routinely checked alarm limits for various parameters. 50% PGs and 46.6% SRs set these alarm limits. The initial response to an alarm among all the residents was to disable the alarm temporarily and try to look for a cause. 92% of PGs and 98% of SRs were aware of alarms priority and colour coding. 55% residents believed that the alarm occurred due to patient disturbance, 15% believed that alarm was due to technical problem with monitor/sensor and 30% thought it was truly related to patient's clinical status. 82% residents set the alarms by themselves, 10% believed that alarms should be adjusted by nurse, 4% believed the technical staff should take responsibility of setting alarm limits and 4% believed that alarm levels should be pre-adjusted by the manufacturer. We conclude that although alarms are an important, indispensable, and lifesaving feature, they can be a nuisance and can compromise quality and safety of care by frequent false positive alarms. We should be familiar of the alarm modes, check and reset the alarm settings at regular interval or after a change in clinical status of the patient. PMID:21224968

  4. Integration of criticality alarm system at a fuel manufacturing facility

    Energy Technology Data Exchange (ETDEWEB)

    Longinov, M.; Pant, A. [Zircatec Precision Industries, Port Hope, Ontario (Canada)

    2005-07-01

    In response to the Power Uprate program at Bruce Power, Zircatec has committed to introduce, by Spring 2006 a new manufacturing line for the production of 43 element CANFLEX bundles containing Slightly Enriched Uranium (SEU) with a centre pin of blended dysprosia/urania (BDU). This is a new fuel design and is the first change in fuel design since the introduction of the current 37 element fuel over 20 years ago. As the primary fuel supplier to the reactor site that has chosen to utilize this new fuel design, Zircatec has agreed to manufacture and supply this new fuel at their facility in Port Hope, Ontario. Under this agreement, Zircatec is challenged with converting a fuel manufacturing facility to include the processing of enriched uranium. The challenge is to introduce the new concept of criticality control to a facility that traditionally does not have to deal with such a concept. One of the elements of the implementation is the criticality detection and alarm system - CIDAS. Since a criticality could go undetected by human senses, one of the methods of ensuring safety from radiation exposure in the event of a criticality is the installation of a criticality incident detection and alarm system. This early warning device could be the difference between low dose exposure and lethal exposure. This paper describes the challenges that Zircatec has faced with the installation of a criticality incident detection and alarm system. These challenges include determining the needs and requirements, determining appropriate specifications, selecting the right equipment, installing the equipment and training personnel in the operation of the new equipment. (author)

  5. HISTAMINE BIOSENSOR: A REVIEW

    Directory of Open Access Journals (Sweden)

    Niraj*, M. M. Gupta and Shweta Pandey

    2012-11-01

    Full Text Available Some biogenic amine like Histamine, cadaverine and putrescine have been confirmed as useful chemical indicators to estimate bacterial spoilage of foods, particularly fish and fish products, cheese, meat and fermented foods. Histamine is toxic at high intakes, while cadaverine and putrescine potentiate the effects of Histamine. Histamine has regulated level of 200 mg/kg (200 ppm. Basic principle involved in Biogenic amines biosensor is the action of diamine oxidase (DAO that catalyzes the oxidative deamination of primary amines to the corresponding aldehydes, hydrogen peroxide and ammonia. Two different approaches for the histamine biosensor design were studied, i.e. the enzyme DAO was directly immobilized on the surface of the oxygen electrode membrane using glutaraldehyde or entrapped in a hydrogel film. In histamine biosensor consisting of diamine oxidase (DAO and a conventional oxygen electrode transducer was developed and applied for the determination of standard histamine solutions. For immobilisation with glutaraldehyde, the enzyme was cross-linked with glutaraldehyde as a bifunctional reagent on the electrode surface. For entrapment, DAO was entrapped in a polymeric hydrogel film, i.e. poly(hydroxyl ethyl methacrylate (pHEMA polymer and deposited onto the teflon membrane of the oxygen electrode. Good linear correlation response obtained of the histamine biosensors with immobilized DAO showed between the changes of oxygen level with changes in concentration of histamine at both high concentration ranges (200-1000 mg/L and low concentrations (20-100 mg/L. However, the sensitivity of the biosensor response decreased at high concentration range of histamine, for the direct DAO immobilisation with glutaraldehyde. Biogenic amines concentration can be measured by monitoring either the decrease in oxygen or the increase of hydrogen peroxide concentration.

  6. An Undergraduate Experiment in Alarm System Design.

    Science.gov (United States)

    Martini, R. A.; And Others

    1988-01-01

    Describes an experiment involving data acquisition by a computer, digital signal transmission from the computer to a digital logic circuit and signal interpretation by this circuit. The system is being used at the Illinois Institute of Technology. Discusses the fundamental concepts involved. Demonstrates the alarm experiment as it is used in…

  7. 46 CFR 63.15-7 - Alarms.

    Science.gov (United States)

    2010-10-01

    ... reset. (c) For steam boilers, operation of the lower low water cutoff must automatically sound an... periodically unattended machinery space, the auxiliary boiler trip alarm required by 46 CFR 62.35-50, Table 62..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING AUTOMATIC AUXILIARY BOILERS...

  8. Lipase Based Biosensors for Triglyceride Determination

    OpenAIRE

    Rosli Nurul Huwaida; Mohd Zain Zainiharyati; Ahmad Nor Monica

    2016-01-01

    A review of methods development in lipase based biosensor for triglyceride determination was briefly discussed. This review focuses on the basic principle of triglyceride biosensor that includes performances of triglyceride biosensor such as limit of detection, response time, and optimization.

  9. Orthos, an alarm system for the ALICE DAQ operations

    Science.gov (United States)

    Chapeland, Sylvain; Carena, Franco; Carena, Wisla; Chibante Barroso, Vasco; Costa, Filippo; Denes, Ervin; Divia, Roberto; Fuchs, Ulrich; Grigore, Alexandru; Simonetti, Giuseppe; Soos, Csaba; Telesca, Adriana; Vande Vyvre, Pierre; von Haller, Barthelemy

    2012-12-01

    ALICE (A Large Ion Collider Experiment) is the heavy-ion detector studying the physics of strongly interacting matter and the quark-gluon plasma at the CERN LHC (Large Hadron Collider). The DAQ (Data Acquisition System) facilities handle the data flow from the detectors electronics up to the mass storage. The DAQ system is based on a large farm of commodity hardware consisting of more than 600 devices (Linux PCs, storage, network switches), and controls hundreds of distributed hardware and software components interacting together. This paper presents Orthos, the alarm system used to detect, log, report, and follow-up abnormal situations on the DAQ machines at the experimental area. The main objective of this package is to integrate alarm detection and notification mechanisms with a full-featured issues tracker, in order to prioritize, assign, and fix system failures optimally. This tool relies on a database repository with a logic engine, SQL interfaces to inject or query metrics, and dynamic web pages for user interaction. We describe the system architecture, the technologies used for the implementation, and the integration with existing monitoring tools.

  10. Gold nanoparticles embedded silicon channel biosensor for improved sensitivity

    Science.gov (United States)

    Chang, H. Y.; Arshad, M. K. Md.; M. Nuzaihan M., N.; Fathil, M. F. M.; Hashim, U.

    2016-07-01

    This project discusses the fabrication steps of a biosensor device on silicon-on-insulator (SOI) wafer. Conventional photolithography technique is used to fabricate the device. The gold nanoparticles (GNPs) are then used to enhance the sensitivity of the device. By incorporating the GNPs, it is expected to get higher current compared with the device without GNPs due to better conductivity of gold and higher volume-to-ratio. Hence, with the addition of GNPs, it may boost up the signal and enhance the sensitivity of the device.

  11. Electrochemical biosensors in pharmaceutical analysis

    OpenAIRE

    Eric de Souza Gil; Giselle Rodrigues de Melo

    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...

  12. Panic, Suffocation False Alarms, Separation Anxiety and Endogenous Opioids

    OpenAIRE

    Preter, Maurice; KLEIN, DONALD F.

    2007-01-01

    This review paper presents an amplification of the suffocation false alarm theory (SFA) of spontaneous panic (Klein, 1993). SFA postulates the existence of an evolved physiologic suffocation alarm system that monitors information about potential suffocation. Panic attacks maladaptively occur when the alarm is erroneously triggered. That panic is distinct from Cannon’s emergency fear response and Selye’s General Alarm Syndrome is shown by the prominence of intense air hunger during these attac...

  13. 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.

  14. 30 CFR 57.4360 - Underground alarm systems.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Underground alarm systems. 57.4360 Section 57... MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Fire Prevention and Control Firefighting Procedures/alarms/drills § 57.4360 Underground alarm systems. (a) Fire...

  15. 46 CFR 130.460 - Placement of machinery alarms.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Placement of machinery alarms. 130.460 Section 130.460..., AND MISCELLANEOUS EQUIPMENT AND SYSTEMS Automation of Unattended Machinery Spaces § 130.460 Placement of machinery alarms. (a) Visible and audible alarms must be installed at the pilothouse to...

  16. Optimal alarm system applied in coffee rust

    Directory of Open Access Journals (Sweden)

    Luciene Resende Gonçalves

    2014-02-01

    Full Text Available Alarm systems have very great utility in detecting and warning of catastrophes. This methodology was applied via TARSO model with Bayesian estimation, serving as a forecasting mechanism for coffee rust disease. The coffee culture is very susceptible to this disease causing several records of incidence in most cultivated crops. Researches involving this limiting factor for production are intense and frequent, indicating environmental factors as responsible for the epidemics spread, which does not occur if these factors are not favorable. The fitting type used by the a posteriori probability, allows the system to be updated each time point. The methodology was applied to the rust index series in the presence of the average temperature series. Thus, it is possible to verify the alarm resulted or in a high catastrophe detection in points at which the catastrophe has not occurred, or in the low detections if the point was already in the catastrophe state.

  17. Thermoresponsive amperometric glucose biosensor.

    Science.gov (United States)

    Pinyou, Piyanut; Ruff, Adrian; Pöller, Sascha; Barwe, Stefan; Nebel, Michaela; Alburquerque, Natalia Guerrero; Wischerhoff, Erik; Laschewsky, André; Schmaderer, Sebastian; Szeponik, Jan; Plumeré, Nicolas; Schuhmann, Wolfgang

    2016-03-01

    The authors report on the fabrication of a thermoresponsive biosensor for the amperometric detection of glucose. Screen printed electrodes with heatable gold working electrodes were modified by a thermoresponsive statistical copolymer [polymer I: poly(ω-ethoxytriethylenglycol methacrylate-co-3-(N,N-dimethyl-N-2-methacryloyloxyethyl ammonio) propanesulfonate-co-ω-butoxydiethylenglycol methacrylate-co-2-(4-benzoyl-phenoxy)ethyl methacrylate)] with a lower critical solution temperature of around 28 °C in aqueous solution via electrochemically induced codeposition with a pH-responsive redox-polymer [polymer II: poly(glycidyl methacrylate-co-allyl methacrylate-co-poly(ethylene glycol)methacrylate-co-butyl acrylate-co-2-(dimethylamino)ethyl methacrylate)-[Os(bpy)2(4-(((2-(2-(2-aminoethoxy)ethoxy)ethyl)amino)methyl)-N,N-dimethylpicolinamide)](2+)] and pyrroloquinoline quinone-soluble glucose dehydrogenase acting as biological recognition element. Polymer II bears covalently bound Os-complexes that act as redox mediators for shuttling electrons between the enzyme and the electrode surface. Polymer I acts as a temperature triggered immobilization matrix. Probing the catalytic current as a function of the working electrode temperature shows that the activity of the biosensor is dramatically reduced above the phase transition temperature of polymer I. Thus, the local modulation of the temperature at the interphase between the electrode and the bioactive layer allows switching the biosensor from an on- to an off-state without heating of the surrounding analyte solution. PMID:26702635

  18. Optimal design of label-free silicon “lab on a chip” biosensors

    Institute of Scientific and Technical Information of China (English)

    Yaping Zhang

    2013-01-01

    This paper reported the optimal design of label-free silicon on insulator (SOI)“lab on a chip”biosensors. These devices are designed on the basis of the evanescent field detection principles and interferometer technologies. The well-established silicon device process technology can be applied to fabricate and test these biosensor devices. In addition, these devices can be monolithically integrated with CMOS electronics and microfluidics. For these biosensor devices, multi-mode interferometer (MMI) was employed to combine many stand-alone biosensors to form chip-level biosensor arrays, which enable real-time and label-free monitoring and parallel detection of various analytes in multiple test samples. This sensing and detection technology features the highest detection sensitivity, which can detect analytes at extremely low concentrations instantaneously. This research can lead to innovative commercial development of the new generation of high sensitivity biosensors for a wide range of applications in many fields, such as environmental monitoring, food security control, medical and biological applications.

  19. Car Alarm System Engineered In Arduino Environment

    OpenAIRE

    Järvelä, Sakari

    2014-01-01

    This thesis is targeting to develop and engineer a burglar alarm system prototype using the software and hardware environment Arduino, which is originally manufactured by Smart Projects. The system under development provides a versatile theft inhibition hardware configuration for the holder of the system. It also provides vehicle localization enabling features in case of theft. In the final project, the aim is not to reach commercial benefit. The aim is to get familiar with software libra...

  20. APLIKASI SENSOR CAHAYA UNTUK ALARM ANTI PENCURI

    OpenAIRE

    Asita Shoman Muzaki; Arief Hendra Saptadi; Wahyu Pamungkas

    2013-01-01

    Kasus pencurian di rumah kosong yang ditinggal pergi oleh pemiliknya belakangan ini marak terjadi. Berangkat dari pemikiran ini penulis mencoba merancang alarm yang dapat mendeteksi pergerakan seseorang saat rumah dalam kondisi kosong, ditinggalkan oleh pemiliknya. Alat ini mempunyai prinsip kerja yaitu mendeteksi bayangan seseorang yang melewati titik tertentu. Perancangan dan pembuatan perangkat ini menggunakan sensor cahaya berupa LASER dan LDR yang dirangkai dengan transistor sebagai sakl...

  1. Parental alarm calls suppress nestling vocalization.

    OpenAIRE

    Platzen, Dirk; Magrath, Robert D.

    2004-01-01

    Evolutionary models suggest that the cost of a signal can ensure its honesty. Empirical studies of nestling begging imply that predator attraction can impose such a cost. However, parents might reduce or abolish this cost by warning young of the presence of danger. We tested, in a controlled field playback experiment, whether alarm calls cause 5-, 8- and 11-day-old nestlings of the white-browed scrubwren, Sericornis frontalis, to suppress vocalization. In this species, nestlings vocalize when...

  2. Research and implementation of intelligent alarm transceiver

    Institute of Scientific and Technical Information of China (English)

    Haobo long; XiaolingTian

    2015-01-01

    To design and implement a inteligent alarm transceiver, the sensor, such as temperature, voltage, video check. is used in transceiver. Then it analyses real-time acquisition data of sensor, if the transceiver is not working normaly, and the results are sent to the host computer. And the latter send fault information to user by mobile phone. During this period, without artificial participation, to achieve the purpose of inteligent warning. it can improve the maintenance efficiency of transceiver.

  3. Science communication and the Swedish acrylamide "alarm".

    Science.gov (United States)

    Lofstedt, Ragnar E

    2003-01-01

    On April 24, 2002 the Swedish National Food Administration along with a group of researchers at the University of Stockholm raised an alarm regarding potential health risks associated with eating fried and baked foods such as potatoes and bread. Scientists had found high levels of acrylamide (up to 500 times more acrylamide than that allowed in drinking water by the World Health Organisation), a substance widely believed to cause cancer, in cooked high starch foods. The outcomes of this "alarm" were immediate. In Sweden sales of chips fell by 30-50 percent over a 3-day period following the press conference, and share prices among several fried food manufacturers fell substantially, as stock analysts were fearful that consumption of fried foods would decrease significantly. Four days after the press conference, however, consumers began eating fried food as normal and a number of researchers and journalists in Sweden and elsewhere took the view that the alarm had been both exaggerated and ill placed. In this study, I evaluate the science communication process associated with the scare, based on a content analysis of a select group of Swedish broad sheets from just previous to the April 2002 press conference to the present time (December 2002). In addition, the study is based on interviews with the various Swedish regulators involved in the process itself (in particular at the Swedish National Food Administration) as well as with the scientists responsible for the study at Stockholm University and relevant journalists and politicians.

  4. Biosensors and invasive monitoring in clinical applications

    CERN Document Server

    Córcoles, Emma P

    2013-01-01

    This volume examines the advances of invasive monitoring by means of biosensors and microdialysis. Physical and physiological parameters are commonly monitored in clinical settings using invasive techniques due to their positive outcome in patients’ diagnosis and treatment. Biochemical parameters, however, still rely on off-line measurements and require large pieces of equipment. Biosensing and sampling devices present excellent capabilities for their use in continuous monitoring of patients’ biochemical parameters. However, certain issues remain to be solved in order to ensure a more widespread use of these techniques in today’s medical practices.

  5. Energy harvesting for human wearable and implantable bio-sensors.

    Science.gov (United States)

    Mitcheson, Paul D

    2010-01-01

    There are clear trade-offs between functionality, battery lifetime and battery volume for wearable and implantable wireless-biosensors which energy harvesting devices may be able to overcome. Reliable energy harvesting has now become a reality for machine condition monitoring and is finding applications in chemical process plants, refineries and water treatment works. However, practical miniature devices that can harvest sufficient energy from the human body to power a wireless bio-sensor are still in their infancy. This paper reviews the options for human energy harvesting in order to determine power availability for harvester-powered body sensor networks. The main competing technologies for energy harvesting from the human body are inertial kinetic energy harvesting devices and thermoelectric devices. These devices are advantageous to some other types as they can be hermetically sealed. In this paper the fundamental limit to the power output of these devices is compared as a function of generator volume when attached to a human whilst walking and running. It is shown that the kinetic energy devices have the highest fundamental power limits in both cases. However, when a comparison is made between the devices using device effectivenesses figures from previously demonstrated prototypes presented in the literature, the thermal device is competitive with the kinetic energy harvesting device when the subject is running and achieves the highest power density when the subject is walking.

  6. 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.

  7. DNA-Metallodrugs Interactions Signaled by Electrochemical Biosensors: An Overview

    Directory of Open Access Journals (Sweden)

    Mauro Ravera

    2007-01-01

    Full Text Available The interaction of drugs with DNA is an important aspect in pharmacology. In recent years, many important technological advances have been made to develop new techniques to monitor biorecognition and biointeraction on solid devices. The interaction between DNA and drugs can cause chemical and conformational modifications and, thus, variation of the electrochemical properties of nucleobases. The propensity of a given compound to interact with DNA is measured as a function of the decrease of guanine oxidation signal on a DNA electrochemical biosensor. Covalent binding at N7 of guanine, electrostatic interactions, and intercalation are the events that this kind of biosensor can detect. In this context, the interaction between a panel of antitumoral Pt-, Ru-, and Ti-based metallodrugs with DNA immobilized on screen-printed electrodes has been studied. The DNA biosensors are used for semiquantitative evaluation of the analogous interaction occurring in the biological environment.

  8. Advances in arsenic biosensor development--a comprehensive review.

    Science.gov (United States)

    Kaur, Hardeep; Kumar, Rabindra; Babu, J Nagendra; Mittal, Sunil

    2015-01-15

    Biosensors are analytical devices having high sensitivity, portability, small sample requirement and ease of use for qualitative and quantitative monitoring of various analytes of human importance. Arsenic (As), owing to its widespread presence in nature and high toxicity to living creatures, requires frequent determination in water, soil, agricultural and food samples. The present review is an effort to highlight the various advancements made so far in the development of arsenic biosensors based either on recombinant whole cells or on certain arsenic-binding oligonucleotides or proteins. The role of futuristic approaches like surface plasmon resonance (SPR) and aptamer technology has also been discussed. The biomethods employed and their general mechanisms, advantages and limitations in relevance to arsenic biosensors developed so far are intended to be discussed in this review.

  9. Printable Ultrathin Metal Oxide Semiconductor-Based Conformal Biosensors.

    Science.gov (United States)

    Rim, You Seung; Bae, Sang-Hoon; Chen, Huajun; Yang, Jonathan L; Kim, Jaemyung; Andrews, Anne M; Weiss, Paul S; Yang, Yang; Tseng, Hsian-Rong

    2015-12-22

    Conformal bioelectronics enable wearable, noninvasive, and health-monitoring platforms. We demonstrate a simple and straightforward method for producing thin, sensitive In2O3-based conformal biosensors based on field-effect transistors using facile solution-based processing. One-step coating via aqueous In2O3 solution resulted in ultrathin (3.5 nm), high-density, uniform films over large areas. Conformal In2O3-based biosensors on ultrathin polyimide films displayed good device performance, low mechanical stress, and highly conformal contact determined using polydimethylsiloxane artificial skin having complex curvilinear surfaces or an artificial eye. Immobilized In2O3 field-effect transistors with self-assembled monolayers of NH2-terminated silanes functioned as pH sensors. Functionalization with glucose oxidase enabled d-glucose detection at physiologically relevant levels. The conformal ultrathin field-effect transistor biosensors developed here offer new opportunities for future wearable human technologies. PMID:26498319

  10. Printable Ultrathin Metal Oxide Semiconductor-Based Conformal Biosensors.

    Science.gov (United States)

    Rim, You Seung; Bae, Sang-Hoon; Chen, Huajun; Yang, Jonathan L; Kim, Jaemyung; Andrews, Anne M; Weiss, Paul S; Yang, Yang; Tseng, Hsian-Rong

    2015-12-22

    Conformal bioelectronics enable wearable, noninvasive, and health-monitoring platforms. We demonstrate a simple and straightforward method for producing thin, sensitive In2O3-based conformal biosensors based on field-effect transistors using facile solution-based processing. One-step coating via aqueous In2O3 solution resulted in ultrathin (3.5 nm), high-density, uniform films over large areas. Conformal In2O3-based biosensors on ultrathin polyimide films displayed good device performance, low mechanical stress, and highly conformal contact determined using polydimethylsiloxane artificial skin having complex curvilinear surfaces or an artificial eye. Immobilized In2O3 field-effect transistors with self-assembled monolayers of NH2-terminated silanes functioned as pH sensors. Functionalization with glucose oxidase enabled d-glucose detection at physiologically relevant levels. The conformal ultrathin field-effect transistor biosensors developed here offer new opportunities for future wearable human technologies.

  11. 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.

  12. Development of an electrochemical biosensor for alkylphenol detection.

    Science.gov (United States)

    Belkhamssa, Najet; da Costa, João P; Justino, Celine I L; Santos, Patrícia S M; Cardoso, Susana; Duarte, Armando C; Rocha-Santos, Teresa; Ksibi, Mohamed

    2016-09-01

    In this work, electrochemical biosensors based on field effect transistors (FET) with single-walled carbon nanotubes (SWCNT) were constructed as disposable analytical devices to detect alkylphenols through immunoreaction using 4-nonylphenol (NP) as model analyte, and validated by comparison with enzyme-linked immunosorbent assay (ELISA). The calibration curve displays a working range with five concentrations between 5 and 500µgL(-1), and for each concentration, five biosensors were analysed for reproducibility estimation and two analytical measurements were performed for each biosensor for repeatability estimation. The accuracy of the biosensors was validated by analyzing NP contents in ten spiked artificial seawater samples and comparing these results to those obtained with the traditional ELISA methodology. Excellent analytical performance was obtained with reproducibility of 0.56±0.08%, repeatability of 0.5±0.2%, limit of detection for NP as low as 5µgL(-1), and average recovery between 97.8% and 104.6%. This work demonstrates that simple biosensors can be used to detect hazardous priority substances in seawater samples, even at low concentrations. PMID:27343574

  13. Visual optical biosensors based on DNA-functionalized polyacrylamide hydrogels.

    Science.gov (United States)

    Khimji, Imran; Kelly, Erin Y; Helwa, Youssef; Hoang, Michael; Liu, Juewen

    2013-12-15

    Biosensors are devices that can provide quantitative or semi-quantitative analytical information about target molecules, where molecular recognition is based on biomolecular interactions. In recent years, DNA has emerged as a useful molecule for biosensor development since DNA can not only recognize its complementary strand, but also metal ions, small molecules, proteins and cells utilizing DNA aptamer technology. Converting DNA binding events into useful biosensors often require sensor immobilization. Among the various materials for sensor immobilization, hydrogels are particularly attractive. Hydrogels are crosslinked hydrophilic polymer networks that undergo swelling in water. In a gel, DNA immobilization can take place in 3D, allowing for high DNA loading capacity. Hydrogels are transparent, offering low optical background. The gel volume is affected by many environmental parameters such as temperature, pH, ionic strength, and solvent composition. In this paper, we present a concise summary of recent developments in DNA-functionalized hydrogel biosensors for visual detection. Detailed methods for immobilizing DNA biosensors in monolithic polyacrylamide gels and gel microparticles are supplied. PMID:23978515

  14. Over-the-Counter Biosensors: Past, Present, and Future

    Directory of Open Access Journals (Sweden)

    Thomas Ming-Hung Lee

    2008-09-01

    Full Text Available The demand for specific, low cost, rapid, sensitive and easy detection of biomolecules is huge. A well-known example is the glucose meters used by diabetics to monitor their blood glucose levels. Nowadays, a vast majority of the glucose meters are based on electrochemical biosensor technology. The inherent small size and simple construction of the electrochemical transducer and instrument are ideally suited for pointof-care biosensing. Besides glucose, a wide variety of electrochemical biosensors have been developed for the measurements of some other key metabolites, proteins, and nucleic acids. Nevertheless, unlike the glucose meters, limited success has been achieved for the commercialization of the protein and nucleic acid biosensors. In this review article, key technologies on the electrochemical detection of key metabolites, proteins, and DNAs are discussed in detail, with particular emphasis on those that are compatible to home-use setting. Moreover, emerging technologies of lab-on-a-chip microdevices and nanosensors (i.e., silicon and carbon nanotube field-effect sensors offer opportunities for the construction of new generation biosensors with much better performances. Together with the continuous innovations in the basic components of biosensors (i.e., transducers, biorecognition molecules, immobilization and signal transduction schemes, consumers could soon buy different kinds of biosensing devices in the pharmacy stores.

  15. The Quantitative Overhead Analysis for Effective Task Migration in Biosensor Networks

    Directory of Open Access Journals (Sweden)

    Sung-Min Jung

    2013-01-01

    Full Text Available We present a quantitative overhead analysis for effective task migration in biosensor networks. A biosensor network is the key technology which can automatically provide accurate and specific parameters of a human in real time. Biosensor nodes are typically very small devices, so the use of computing resources is restricted. Due to the limitation of nodes, the biosensor network is vulnerable to an external attack against a system for exhausting system availability. Since biosensor nodes generally deal with sensitive and privacy data, their malfunction can bring unexpected damage to system. Therefore, we have to use a task migration process to avoid the malfunction of particular biosensor nodes. Also, it is essential to accurately analyze overhead to apply a proper migration process. In this paper, we calculated task processing time of nodes to analyze system overhead and compared the task processing time applied to a migration process and a general method. We focused on a cluster ratio and different processing time between biosensor nodes in our simulation environment. The results of performance evaluation show that task execution time is greatly influenced by a cluster ratio and different processing time of biosensor nodes. In the results, the proposed algorithm reduces total task execution time in a migration process.

  16. Biosensors. New developments and opportunities in the diagnosis of livestock diseases

    International Nuclear Information System (INIS)

    Phenomenal growth in the field of biosensors has been observed in recent years, with applications in a wide range of disciplines, including food, environment and medical analysis. The need for high sensitivity, speed and accuracy of analytical measurements has stimulated considerable interest in developing sensors as diagnostic tools. Substances with recognition powers are available naturally in the form of antibodies, enzymes, cell receptors, nucleic acids and lectins. These can be used as the sensing element in biosensors, and therefore a wide range of analytes can be detected and measured using these devices. A wide range of transducers are also feasible. Biosensors are suitable devices to fulfil the rapid monitoring needs of the diagnostic market. They have the great advantage over many other analytical methods in that they can be incorporated into simple to use instruments. Immunochemical sensors are powerful analytical devices which enable the identification of a wide range of target molecules. These devices combine the selectivity of antibodies with the sensitivity and rapid measurement of a biosensor. The rapid development of immunosensor technology during the last few years opens new perspectives for the development of relatively inexpensive applications to monitor livestock and their products. The paper deals with recent developments in biosensor technology and assesses the current and potential use of biosensors in the diagnosis and control of livestock diseases. (author)

  17. Visual display and alarm system for wind tunnel static and dynamic loads

    Science.gov (United States)

    Hanly, Richard D.; Fogarty, James T.

    1987-01-01

    A wind tunnel balance monitor and alarm system developed at NASA Ames Research Center will produce several beneficial results. The costs of wind tunnel delays because of inadvertent balance damage and the costs of balance repair or replacement can be greatly reduced or eliminated with better real-time information on the balance static and dynamic loading. The wind tunnel itself will have enhanced utility with the elimination of overly cautious limits on test conditions. The microprocessor-based system features automatic scaling and 16 multicolored LED bargraphs to indicate both static and dynamic components of the signals from eight individual channels. Five individually programmable alarm levels are available with relay closures for internal or external visual and audible warning devices and other functions such as automatic activation of external recording devices, model positioning mechanisms, or tunnel shutdown.

  18. Kidkit guides children into alarming atmospheres

    DEFF Research Database (Denmark)

    Højlund, Marie; Kinch, Sofie

    2013-01-01

    on the development and evaluation of Kidkit, which is interactive furniture designed for young children who are going to visit a hospitalized relative with fatal injuries for the first time. Kidkit empowers the child to engage and be present by shaping Middle Ground Experiences in the hospital ward environment...... that is full of intimidating medical equipment and alarms. The evaluation results indicate collective rewards gained when children succeed in Embodied Habituation. Finally, the paper discusses how Middle Ground Experiences inevitably establish grounds for how we design for spatial experiences within...

  19. Dielectric modulated overlapping gate-on-drain tunnel-FET as a label-free biosensor

    Science.gov (United States)

    Abdi, Dawit Burusie; Kumar, M. Jagadesh

    2015-10-01

    In this paper, based on the concept of dielectric-modulation, we have proposed a tunnel field effect transistor (TFET) biosensor with a nanogap created by overlapping the gate on the drain side. Sensing in the proposed device is due to a change in the ambipolar current of the transistor when biomolecules with different dielectric constant are immobilized in the nanogap. The maximum ratio of the drain current with absence and presence of biomolecules, which indicates the sensitivity, is as high as 1010. In comparison to other field effect transistor (FET) based biosensors, using TFET as a biosensor not only gives higher sensitivity but also the advantage of low leakage.

  20. Papers Based Electrochemical Biosensors: From Test Strips to Paper-Based Microfluidics

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Bingwen; Du, Dan; Hua, Xin; Yu, Xiao-Ying; Lin, Yuehe

    2014-05-08

    Papers based biosensors such as lateral flow test strips and paper-based microfluidic devices (or paperfluidics) are inexpensive, rapid, flexible, and easy-to-use analytical tools. An apparent trend in their detection is to interpret sensing results from qualitative assessment to quantitative determination. Electrochemical detection plays an important role in quantification. This review focuses on electrochemical (EC) detection enabled biosensors. The first part provides detailed examples in paper test strips. The second part gives an overview of paperfluidics engaging EC detections. The outlook and recommendation of future directions of EC enabled biosensors are discussed in the end.

  1. Bi nanowire-based thermal biosensor for the detection of salivary cortisol using the Thomson effect

    Science.gov (United States)

    Lee, Seunghyun; Hyun Lee, Jung; Kim, MinGin; Kim, Jeongmin; Song, Min-Jung; Jung, Hyo-Il; Lee, Wooyoung

    2013-09-01

    We present a study of a thermal biosensor based on bismuth nanowire that is fabricated for the detection of the human stress hormone cortisol using the Thomson effect. The Bi nanowire was grown using the On-Film Formation of Nanowires (OFF-ON) method. The thermal device was fabricated using photolithography, and the sensing area was modified with immobilized anti-cortisol antibodies conjugated with protein G for the detection of cortisol. The voltages were measured with two probe tips during surface modification to investigate the biochemical reactions in the fabricated thermal biosensor. The Bi nanowire-based thermal biosensor exhibited low detection limit and good selectivity for the detection of cortisol.

  2. A high content assay for biosensor validation and for examining stimuli that affect biosensor activity

    OpenAIRE

    Slattery, Scott D.; Hahn, Klaus M.

    2014-01-01

    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 differenc...

  3. Alarm management in gas pipeline plant: a case study

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Juliano; Lima, Marcelo; Leitao, Gustavo; Guedes, Luiz Affonso [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Branco, Nicolau; Coelho, Robson; Elias, Gustavo Passos; Nunes, Marcelo [Transportadora Brasileira Gasoduto Bolivia-Brasil (TBG), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    In order to improve the requirements of industrial processes, many decision support systems have been introduced in recent years. In this context, the alarm management systems have great relevance. On the other hand, the informatics revolution allowed a great increase of information concerning the operation of the industrial processes. Currently, process operators handle an excessive number of about 1.500 alarms per day. Thus, this overdose of information implies in the discredit of alarms. Then, in order to improve the operation activities of industrial processes, it is mandatory to incorporate procedures to evaluate and rationalize alarms. Since the EMMUA191 Standard is the reference guide to alarm management, but it does not specify how to execute an alarm management procedure, in this paper, a systematic procedure to evaluate alarms configurations in industrial processes is proposed. This procedure is in line with EMMUA191 and is composed by the following steps: to use statistics analyses to identify problematic alarms, such as occurrence, intermittency, correlation, and flooding calculation; to indicate problematic alarm group; and to propose a set of actions to be implemented. To validate our proposal, we present a case study in a gas pipeline plant using the BR-AlarmExpert software. (author)

  4. 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.

  5. A Novel Cell-Based Hybrid Acoustic Wave Biosensor with Impedimetric Sensing Capabilities

    OpenAIRE

    Ioana Voiculescu; Anis Nurashikin Nordin; Fang Li; Fei Liu

    2013-01-01

    A novel multiparametric biosensor system based on living cells will be presented. The biosensor system includes two biosensing techniques on a single device: resonant frequency measurements and electric cell-substrate impedance sensing (ECIS). The multiparametric sensor system is based on the innovative use of the upper electrode of a quartz crystal microbalance (QCM) resonator as working electrode for the ECIS technique. The QCM acoustic wave sensor consists of a thin AT-cut quartz substrate...

  6. Bioelectrochemical interface engineering: toward the fabrication of electrochemical biosensors, biofuel cells, and self-powered logic biosensors.

    Science.gov (United States)

    Zhou, Ming; Dong, Shaojun

    2011-11-15

    Over the past decade, researchers have devoted considerable attention to the integration of living organisms with electronic elements to yield bioelectronic devices. Not only is the integration of DNA, enzymes, or whole cells with electronics of scientific interest, but it has many versatile potential applications. Researchers are using these ideas to fabricate biosensors for analytical applications and to assemble biofuel cells (BFCs) and biomolecule-based devices. Other research efforts include the development of biocomputing systems for information processing. In this Account, we focus on our recent progress in engineering at the bioelectrochemical interface (BECI) for the rational design and construction of important bioelectronic devices, ranging from electrochemical (EC-) biosensors to BFCs, and self-powered logic biosensors. Hydrogels and sol-gels provide attractive materials for the immobilization of enzymes because they make EC-enzyme biosensors stable and even functional in extreme environments. We use a layer-by-layer (LBL) self-assembly technique to fabricate multicomponent thin films on the BECI at the nanometer scale. Additionally, we demonstrate how carbon nanomaterials have paved the way for new and improved EC-enzyme biosensors. In addition to the widely reported BECI-based electrochemical impedance spectroscopy (EIS)-type aptasensors, we integrate the LBL technique with our previously developed "solid-state probe" technique for redox probes immobilization on electrode surfaces to design and fabricate BECI-based differential pulse voltammetry (DPV)-type aptasensors. BFCs can directly harvest energy from ambient biofuels as green energy sources, which could lead to their application as simple, flexible, and portable power sources. Porous materials provide favorable microenvironments for enzyme immobilization, which can enhance BFC power output. Furthermore, by introducing aptamer-based logic systems to BFCs, such systems could be applied as self

  7. General methods for alarm reduction; Larmsanering med generella metoder

    Energy Technology Data Exchange (ETDEWEB)

    Ahnlund, Jonas; Bergquist, Tord; Raaberg, Martin [Lund Univ. (Sweden). Dept. of Information Technology

    2003-10-01

    The information in the control rooms has increased due to the technological advances in process control. Large industries produce large data quantities, where some information is unnecessary or even incorrect. The operator needs support from an advanced and well-adjusted alarm system to be able to separate a real event from a minor disturbance. The alarms must be of assistance and not a nuisance. An enhanced alarm situation qualifies an increased efficiency with fewer production disturbances and an improved safety. Yet, it is still unusual that actions are taken to improve the situation. An alarm cleanup with general methods can shortly be described as taking advantage of the control systems built-in functions, the possibility to modify or create function blocks and fine-tune the settings in the alarm system. In this project, we make use of an intelligent software, Alarm Cleanup Toolbox, that simulate different signal processing methods and tries to find improved settings on all the signals in the process. This is a fast and cost-efficient way to improve the overall alarm situation, and lays a foundation for more advanced alarm systems. An alarm cleanup has been carried out at Flintraennan district heating plant in Malmoe, where various signal processing methods has been implemented in a parallel alarm system. This made it possible to compare the two systems under the same conditions. The result is very promising, and shows that a lot of improvements can be achieved with very little effort. An analysis of the alarm system at Vattenreningen (the water purification process) at Heleneholmsverket in Malmoe has been carried out. Alarm Cleanup Toolbox has, besides suggesting improved settings, also found logical errors in the alarm system. Here, no implementation was carried out and therefore the results are analytical, but they validate the efficiency of the general methods. The project has shown that an alarm cleanup with general methods is cost-efficient, and that the

  8. Plasmonic paper: an emerging analytical platform for highly sensitive biosensors (Conference Presentation)

    Science.gov (United States)

    Singamaneni, Srikanth

    2016-03-01

    Plasmonic biosensors hold enormous potential for the development of low-cost, label-free, point-of-care biodiagnostics. However, two major challenges need to be overcome to reap the benefits of this class of biosensors: (i) state-of-the-art plasmonic biosensors either offer limited sensitivity or are impractical for real-world applications due to their poor stability and excessive cost; (ii) these biosensors rely on natural antibodies, which are high-cost and impose severe limitations in handling, storage and device integration. We demonstrate that a common filter paper can be transformed into a plasmonic sensing platform for highly sensitive and selective detection of trace levels of chemical and biological analytes. We also demonstrate that short peptides as biorecognition elements compared to larger antibodies as target capture agents offer several advantages. Using a bioplasmonic paper device, we demonstrate the selective and sensitive detection of the cardiac biomarker troponin I. The smaller sized peptide provides higher sensitivity and a lower detection limit using a bioplasmonic paper device. Furthermore, the excellent shelf-life and thermal stability of peptide-based plasmonic biosensors, which precludes the need for special storage conditions, makes it ideal for use in resource-limited settings. We also demonstrate plasmonic biosensors based on artificial antibodies by molecularly imprinting the plasmonic nanotransducers. Apart from significantly lowering the cost, these developments are critical for translating plasmonic sensors to point-of-care and resource-limited settings.

  9. A microfluidic paper-based electrochemical biosensor array for multiplexed detection of metabolic biomarkers

    Directory of Open Access Journals (Sweden)

    Chen Zhao, Martin M Thuo and Xinyu Liu

    2013-01-01

    Full Text Available Paper-based microfluidic devices have emerged as simple yet powerful platforms for performing low-cost analytical tests. This paper reports a microfluidic paper-based electrochemical biosensor array for multiplexed detection of physiologically relevant metabolic biomarkers. Different from existing paper-based electrochemical devices, our device includes an array of eight electrochemical sensors and utilizes a handheld custom-made electrochemical reader (potentiostat for signal readout. The biosensor array can detect several analytes in a sample solution and produce multiple measurements for each analyte from a single run. Using the device, we demonstrate simultaneous detection of glucose, lactate and uric acid in urine, with analytical performance comparable to that of the existing commercial and paper-based platforms. The paper-based biosensor array and its electrochemical reader will enable the acquisition of high-density, statistically meaningful diagnostic information at the point of care in a rapid and cost-efficient way.

  10. A microfluidic paper-based electrochemical biosensor array for multiplexed detection of metabolic biomarkers

    Science.gov (United States)

    Zhao, Chen; Thuo, Martin M.; Liu, Xinyu

    2013-10-01

    Paper-based microfluidic devices have emerged as simple yet powerful platforms for performing low-cost analytical tests. This paper reports a microfluidic paper-based electrochemical biosensor array for multiplexed detection of physiologically relevant metabolic biomarkers. Different from existing paper-based electrochemical devices, our device includes an array of eight electrochemical sensors and utilizes a handheld custom-made electrochemical reader (potentiostat) for signal readout. The biosensor array can detect several analytes in a sample solution and produce multiple measurements for each analyte from a single run. Using the device, we demonstrate simultaneous detection of glucose, lactate and uric acid in urine, with analytical performance comparable to that of the existing commercial and paper-based platforms. The paper-based biosensor array and its electrochemical reader will enable the acquisition of high-density, statistically meaningful diagnostic information at the point of care in a rapid and cost-efficient way.

  11. Biosensors in Endocrinology- Review Article

    OpenAIRE

    Faridbod, Farnoush; Ganjali, Mohammad Reza; Larijani, Bagher; Norouzi, Parviz; Hosseini, Morteza

    2015-01-01

    Biosensors are classes of sensors in which at least a biological process is used in sensing procedure. They are generally composed of three parts: a sensing element, a transducer, and a signal processor (or detector). They can be categorized by type of sensing materials or by detection techniques. From their invention time up to now, various biological species have been analyzed using variety of biosensors. They have been widely used for environmental, industrial, pharmaceutical and clinical ...

  12. Biosensors for functional food safety and analysis.

    Science.gov (United States)

    Lavecchia, Teresa; Tibuzzi, Arianna; Giardi, Maria Teresa

    2010-01-01

    The importance of safety and functionality analysis of foodstuffs and raw materials is supported by national legislations and European Union (EU) directives concerning not only the amount of residues of pollutants and pathogens but also the activity and content of food additives and the health claims stated on their labels. In addition, consumers' awareness of the impact of functional foods' on their well-being and their desire for daily healthcare without the intake pharmaceuticals has immensely in recent years. Within this picture, the availability of fast, reliable, low cost control systems to measure the content and the quality of food additives and nutrients with health claims becomes mandatory, to be used by producers, consumers and the governmental bodies in charge of the legal supervision of such matters. This review aims at describing the most important methods and tools used for food analysis, starting with the classical methods (e.g., gas-chromatography GC, high performance liquid chromatography HPLC) and moving to the use of biosensors-novel biological material-based equipments. Four types of bio-sensors, among others, the novel photosynthetic proteins-based devices which are more promising and common in food analysis applications, are reviewed. A particular highlight on biosensors for the emerging market of functional foods is given and the most widely applied functional components are reviewed with a comprehensive analysis of papers published in the last three years; this report discusses recent trends for sensitive, fast, repeatable and cheap measurements, focused on the detection of vitamins, folate (folic acid), zinc (Zn), iron (Fe), calcium (Ca), fatty acids (in particular Omega 3), phytosterols and phytochemicals. A final market overview emphasizes some practical aspects ofbiosensor applications.

  13. The electrophotonic silicon biosensor

    Science.gov (United States)

    Juan-Colás, José; Parkin, Alison; Dunn, Katherine E.; Scullion, Mark G.; Krauss, Thomas F.; Johnson, Steven D.

    2016-01-01

    The emergence of personalized and stratified medicine requires label-free, low-cost diagnostic technology capable of monitoring multiple disease biomarkers in parallel. Silicon photonic biosensors combine high-sensitivity analysis with scalable, low-cost manufacturing, but they tend to measure only a single biomarker and provide no information about their (bio)chemical activity. Here we introduce an electrochemical silicon photonic sensor capable of highly sensitive and multiparameter profiling of biomarkers. Our electrophotonic technology consists of microring resonators optimally n-doped to support high Q resonances alongside electrochemical processes in situ. The inclusion of electrochemical control enables site-selective immobilization of different biomolecules on individual microrings within a sensor array. The combination of photonic and electrochemical characterization also provides additional quantitative information and unique insight into chemical reactivity that is unavailable with photonic detection alone. By exploiting both the photonic and the electrical properties of silicon, the sensor opens new modalities for sensing on the microscale. PMID:27624590

  14. Noninvasive biosensor for hypoglycemia

    Science.gov (United States)

    Varadan, Vijay K.; Whitchurch, Ashwin K.; Sarukesi, Karunakaran

    2003-01-01

    Hypoglycemia-abnormal decrease in blood sugar- is a major obstacle in the management of diabetes and prevention of long-term complications, and it may impose serious effects on the brain, including impairment of memory and other cognitive functions. This is especially a concern in early childhood years when the nervous system is still developing. Hypoglycemic unawareness (in which the body"s normal ability to signal low blood sugar doesn"t work and an oncoming low blood sugar episode proceeds undetected) is a particularly frightening problem for many people with diabetes. Researchers have now uncovered evidence that repeated bouts of insulin-induced hypoglycemia can harm the brain over time, causing confusion, abnormal behavior, loss of consciousness, and seizures. Extreme cases have resulted in coma and death. In this paper, a non-invasive biosensor in a wrist watch along with a wireless data downloading system is proposed.

  15. 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. PMID:26212206

  16. 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.

  17. Aplikasi Sensor Cahaya Untuk Alarm Anti Pencuri

    Directory of Open Access Journals (Sweden)

    Asita Shoman Muzaki

    2011-11-01

    Full Text Available Kasus pencurian di rumah kosong yang ditinggal pergi oleh pemiliknya belakangan ini marak terjadi. Berangkat dari pemikiran ini penulis mencoba merancang alarm yang dapat mendeteksi pergerakan seseorang saat rumah dalam kondisi kosong, ditinggalkan oleh pemiliknya. Alat ini mempunyai prinsip kerja yaitu mendeteksi bayangan seseorang yang melewati titik tertentu. Perancangan dan pembuatan perangkat ini menggunakan sensor cahaya berupa LASER dan LDR yang dirangkai dengan transistor sebagai saklar otomatis serta LED dan telepon rumah untuk melakukan panggilan kepada nomor telepon pemilik rumah. Komponen yang dipakai dalam pembuatan perangkat ini antara lain IC LM7805, LASER pointer, resistor, transistor BC108, LED, relay dan telepon rumah. Perancangan dan pembuatan alat menggunakan software multisim 10.1 sebagai simulator rangkaian, dan software eagle 5.1.1 untuk mendesain jalur rangkaian pada papan PCB. Saat cahaya LASER tidak sampai ke LDR karena terhalang oleh sesuatu, maka rangkaian output yang berupa indikator LED dan panggilan dari telepon rumah akan aktif

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

    OpenAIRE

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

    2016-01-01

    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, ...

  19. 24 CFR 3280.208 - Smoke alarm requirements.

    Science.gov (United States)

    2010-04-01

    ... locations: (i) To protect both the living area and kitchen space. Manufacturers are encouraged to locate the alarm in the living area remote from the kitchen and cooking appliances. A smoke alarm located within 20... when a home is equipped or designed for future installation of a roof-mounted evaporative cooler...

  20. 33 CFR 127.201 - Sensing and alarm systems.

    Science.gov (United States)

    2010-07-01

    ... systems. (a) Fixed sensors must have audio and visual alarms in the control room and audio alarms nearby. (b) Fixed sensors that continuously monitor for LNG vapors must— (1) Be in each enclosed area where vapor or gas may accumulate; and (2) Meet Section 9-4 of NFPA 59A. (c) Fixed sensors that...

  1. Los Alamos Scientific Laboratory long-range alarm system

    International Nuclear Information System (INIS)

    The Los Alamos Scientific Laboratory (LASL) Long-Range Alarm System is described. The last few years have brought significant changes in the Department of Energy regulations for protection of classified documents and special nuclear material. These changes in regulations have forced a complete redesign of the LASL security alarm system. LASL covers many square miles of varying terrain and consists of separate technical areas connected by public roads and communications. A design study over a period of 2 years produced functional specifications for a distributed intelligence, expandable alarm system that will handle 30,000 alarm points from hundreds of data concentrators spread over a 250-km2 area. Emphasis in the design was on nonstop operation, data security, data communication, and upward expandability to incorporate fire alarms and the computer-aided dispatching of security and fire vehicles. All aspects of the alarm system were to be fault tolerant from the central computer system down to but not including the individual data concentrators. Redundant communications lines travel over public domain from the alarmed area to the central alarm station

  2. 33 CFR 401.16 - Propeller direction alarms.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Propeller direction alarms. 401.16 Section 401.16 Navigation and Navigable Waters SAINT LAWRENCE SEAWAY DEVELOPMENT CORPORATION, DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Condition of Vessels § 401.16 Propeller direction alarms. Every vessel of 1600...

  3. Electropolymerized phenol derivatives as permselective polymers for biosensor applications.

    Science.gov (United States)

    Calia, Giammario; Monti, Patrizia; Marceddu, Salvatore; Dettori, Maria A; Fabbri, Davide; Jaoua, Samir; O'Neill, Robert D; Serra, Pier A; Delogu, Giovanna; Migheli, Quirico

    2015-05-21

    Amperometric biosensors are often coated with a polymeric permselective film to avoid electroactive interference by reducing agents present in the target medium. Phenylenediamine and phenol monomers are commonly used to form these permselective films in the design of microsensors and biosensors. This paper aims to evaluate the permselectivity, stability and lifetime of polymers electrosynthesized using either constant potential amperometry (CPA) or cyclic voltammetry (CV) from naturally occurring phenylpropanoids in monomeric and dimeric forms (eugenol, isoeugenol, dehydrodieugenol and magnolol). Sensors were characterized by scanning electron microscopy and permselectivity analysis. Magnolol formed an electro-deposited polymer with a more defined three-dimensional texture in comparison with the other films. The phenol-derived films showed different permselectivity towards H2O2 over ascorbic acid and dopamine, likely to be related to the thickness and compactness of the polymer. The CV-derived films had a better permselectivity compared to the CPA-corresponding polymers. Based on these results, the permselectivity, stability and lifetime of a biosensor for glucose were studied when a magnolol coating was electro-deposited. The structural principles governing the permselectivity of the magnolol-derived film are suggested to be mainly related to the conformational flexibility of this monomer. Newly designed biosensors, coated with electropolymerized natural phenol derivatives, may represent promising analytical devices for different application fields. PMID:25857616

  4. Role of biomolecular logic systems in biosensors and bioactuators

    Science.gov (United States)

    Mailloux, Shay; Katz, Evgeny

    2014-09-01

    An overview of recent advances in biosensors and bioactuators based on biocomputing systems is presented. Biosensors digitally process multiple biochemical signals through Boolean logic networks of coupled biomolecular reactions and produce an output in the form of a YES/NO response. Compared to traditional single-analyte sensing devices, the biocomputing approach enables high-fidelity multianalyte biosensing, which is particularly beneficial for biomedical applications. Multisignal digital biosensors thus promise advances in rapid diagnosis and treatment of diseases by processing complex patterns of physiological biomarkers. Specifically, they can provide timely detection and alert medical personnel of medical emergencies together with immediate therapeutic intervention. Application of the biocomputing concept has been successfully demonstrated for systems performing logic analysis of biomarkers corresponding to different injuries, particularly as exemplified for liver injury. Wide-ranging applications of multianalyte digital biosensors in medicine, environmental monitoring, and homeland security are anticipated. "Smart" bioactuators, for signal-triggered drug release, for example, were designed by interfacing switchable electrodes with biocomputing systems. Integration of biosensing and bioactuating systems with biomolecular information processing systems advances the potential for further scientific innovations and various practical applications.

  5. Biomolecular logic systems: applications to biosensors and bioactuators

    Science.gov (United States)

    Katz, Evgeny

    2014-05-01

    The paper presents an overview of recent advances in biosensors and bioactuators based on the biocomputing concept. Novel biosensors digitally process multiple biochemical signals through Boolean logic networks of coupled biomolecular reactions and produce output in the form of YES/NO response. Compared to traditional single-analyte sensing devices, biocomputing approach enables a high-fidelity multi-analyte biosensing, particularly beneficial for biomedical applications. Multi-signal digital biosensors thus promise advances in rapid diagnosis and treatment of diseases by processing complex patterns of physiological biomarkers. Specifically, they can provide timely detection and alert to medical emergencies, along with an immediate therapeutic intervention. Application of the biocomputing concept has been successfully demonstrated for systems performing logic analysis of biomarkers corresponding to different injuries, particularly exemplified for liver injury. Wide-ranging applications of multi-analyte digital biosensors in medicine, environmental monitoring and homeland security are anticipated. "Smart" bioactuators, for example for signal-triggered drug release, were designed by interfacing switchable electrodes and biocomputing systems. Integration of novel biosensing and bioactuating systems with the biomolecular information processing systems keeps promise for further scientific advances and numerous practical applications.

  6. Alarm systems a guide to design, management and procurement

    CERN Document Server

    Engineering Equipment and Materials Users' Association. London

    2013-01-01

    Alarm systems form an essential part of the operator interfaces to large modern industrial facilities. They provide vital support to the operators by warning them of situations that need their attention and have an important role in preventing, controlling and mitigating the effects of abnormal situations. Since it was first published in 1999, EEMUA 191 has become the globally accepted and leading guide to good practice for all aspects of alarm systems. The guide, developed by users of alarm systems with input from the GB Health and Safety Executive, gives comprehensive guidance on designing, managing and procuring an effective alarm system. The new Third Edition has been comprehensively updated and includes guidance on implementing the alarm management philosophy in practice; applications in geographically distributed processes; and performance metrics and KPIs.

  7. Biosensors in Health Care: The Milestones Achieved in Their Development towards Lab-on-Chip-Analysis

    Directory of Open Access Journals (Sweden)

    Suprava Patel

    2016-01-01

    Full Text Available Immense potentiality of biosensors in medical diagnostics has driven scientists in evolution of biosensor technologies and innovating newer tools in time. The cornerstone of the popularity of biosensors in sensing wide range of biomolecules in medical diagnostics is due to their simplicity in operation, higher sensitivity, ability to perform multiplex analysis, and capability to be integrated with different function by the same chip. There remains a huge challenge to meet the demands of performance and yield to its simplicity and affordability. Ultimate goal stands for providing point-of-care testing facility to the remote areas worldwide, particularly the developing countries. It entails continuous development in technology towards multiplexing ability, fabrication, and miniaturization of biosensor devices so that they can provide lab-on-chip-analysis systems to the community.

  8. Immune biosensors based on the SPR and TIRE: efficiency of their application for bacteria determination

    Science.gov (United States)

    Starodub, N. F.; Ogorodniichuk, J.; Lebedeva, T.; Shpylovyy, P.

    2013-11-01

    In this work we have designed high-specific biosensors for Salmonella typhimurium detection based on the surface plasmon resonance (SPR) and total internal reflection ellipsometry (TIRE). It has been demonstrated high selectivity and sensitivity of analysis. As a registering part for our experiments the Spreeta (USA) and "Plasmonotest" (Ukraine) with flowing cell have been applied among of SPR device. Previous researches confirmed an efficiency of SPR biosensors using for detecting of specific antigen-antibody interactions therefore this type of reactions with some previous preparations of surface binding layer was used as reactive part. It has been defined that in case with Spreeta sensitivity was on the level 103 - 107 cells/ml. Another biosensor based on the SPR has shown the sensitivity within 101 - 106 cells/ml. Maximal sensitivity was on the level of several cells in 10 ml (up to the fact that less than 5 cells) which has been obtained using the biosensor based on TIRE.

  9. Biosensors in Health Care: The Milestones Achieved in Their Development towards Lab-on-Chip-Analysis

    Science.gov (United States)

    Patel, Suprava; Nanda, Rachita; Sahoo, Sibasish; Mohapatra, Eli

    2016-01-01

    Immense potentiality of biosensors in medical diagnostics has driven scientists in evolution of biosensor technologies and innovating newer tools in time. The cornerstone of the popularity of biosensors in sensing wide range of biomolecules in medical diagnostics is due to their simplicity in operation, higher sensitivity, ability to perform multiplex analysis, and capability to be integrated with different function by the same chip. There remains a huge challenge to meet the demands of performance and yield to its simplicity and affordability. Ultimate goal stands for providing point-of-care testing facility to the remote areas worldwide, particularly the developing countries. It entails continuous development in technology towards multiplexing ability, fabrication, and miniaturization of biosensor devices so that they can provide lab-on-chip-analysis systems to the community. PMID:27042353

  10. From Nanostructure to Nano Biosensor: Institute of Nano Electronic Engineering (INEE, UniMAP Experience

    Directory of Open Access Journals (Sweden)

    U Hashim

    2012-02-01

    Full Text Available Nanostructure is defined as something that has a physical dimension smaller than 100 nanometers, ranging from clusters and/or to dimensional layers of atoms. There are three most important nanostructures that are extensively studied and researched in various organizations including Institute of Nano Electronic Engineering (INEE in UniMAP. These include quantum dot, nanowire, and nanogap, which have been successfully designed and fabricated using in-house facilities available. These are subsequently used as a main sensing component in nanostructures based biosensor. This fabrication, characterization and testing job were done within four main interlinked laboratories namely microfabrication cleanroom, nanofabrication cleanroom, failure analysis laboratory and nano biochip laboratory.  Currently, development of Nano Biosensor is the main research focus in INEE. In principle, biosensor is an analytical device which converts a biological response into an electrical signal.   Keywords: Nanostructure, INEE , nanowire , nanogap and Nano Biosensor

  11. Nano-machining of biosensor electrodes through gold nanoparticles deposition produced by femtosecond laser ablation

    Science.gov (United States)

    Della Ventura, B.; Funari, R.; Anoop, K. K.; Amoruso, S.; Ausanio, G.; Gesuele, F.; Velotta, R.; Altucci, C.

    2015-06-01

    We report an application of femtosecond laser ablation to improve the sensitivity of biosensors based on a quartz crystal microbalance device. The nanoparticles produced by irradiating a gold target with 527-nm, 300-fs laser pulses, in high vacuum, are directly deposited on the quartz crystal microbalance electrode. Different gold electrodes are fabricated by varying the deposition time, thus addressing how the nanoparticles surface coverage influences the sensor response. The modified biosensor is tested by weighting immobilized IgG antibody from goat and its analyte (IgG from mouse), and the results are compared with a standard electrode. A substantial increase of biosensor sensitivity is achieved, thus demonstrating that femtosecond laser ablation and deposition is a viable physical method to improve the biosensor sensitivity by means of nanostructured electrodes.

  12. Modelling a Peroxidase-based Optical Biosensor

    OpenAIRE

    Juozas Kulys; Evelina Gaidamauskait˙e; Romas Baronas

    2007-01-01

    The response of a peroxidase-based optical biosensor was modelled digitally. A mathematical model of the optical biosensor is based on a system of non-linear reaction-diffusion equations. The modelling biosensor comprises two compartments, an enzyme layer and an outer diffusion layer. The digital simulation was carried out using finite difference technique. The influence of the substrate concentration as well as of the thickness of both the enzyme and diffusion layers on the biosensor respons...

  13. 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.

  14. Spill-Detector-and-Shutoff Device

    Science.gov (United States)

    Jarvis, M. R.; Fulton, D. S.

    1985-01-01

    Overflow in liquid chromatography systems rapidly detected and stopped. Spill-detector-and-shutoff device incorporated into liquid-chromatography system. When liquid from output nozzle spills on liquid sensor, device automatically shuts off pump and releases solenoid to pinch off flow in tube. Device uses common type of alarm circuit reset manually before normal operation resumes.

  15. Application and Development of Biosensors

    Institute of Scientific and Technical Information of China (English)

    GAO Yuelin; LI Jichang; HUO Guicheng; LIU Libo

    2008-01-01

    As a new kind of analytical instrument, the principles, types and characters of biosensors were discussed in this paper. A biosensor is usually composed of a recognition element of biological origin and a physicochemical transducer. The biological element is capable of sensing the presence, activity or concentration of a chemical analyse in solution. The sensing takes place either as a binding event or a biocatalyticai event. These into'actions produce a measurable change in a solution property, in which the transducer is converted into a quantifiable electrical signal. The principles, types and applications of biosensors in environmental inspection, food production, clinical medicine and military defense were reviewed, and the trends in research were predicated. Furthermore, an attempt had been made to describe the future development directions and prospects.

  16. Reducing false intracranial pressure alarms using morphological waveform features.

    Science.gov (United States)

    Scalzo, Fabien; Liebeskind, David; Hu, Xiao

    2013-01-01

    False alarms produced by patient monitoring systems in intensive care units are a major issue that causes alarm fatigue, waste of human resources, and increased patient risks. While alarms are typically triggered by manually adjusted thresholds, the trend and patterns observed prior to threshold crossing are generally not used by current systems. This study introduces and evaluates, a smart alarm detection system for intracranial pressure signal (ICP) that is based on advanced pattern recognition methods. Models are trained in a supervised fashion from a comprehensive dataset of 4791 manually labeled alarm episodes extracted from 108 neurosurgical patients. The comparative analysis provided between spectral regression, kernel spectral regression, and support vector machines indicates the significant improvement of the proposed framework in detecting false ICP alarms in comparison to a threshold-based technique that is conventionally used. Another contribution of this work is to exploit an adaptive discretization to reduce the dimensionality of the input features. The resulting features lead to a decrease of 30% of false ICP alarms without compromising sensitivity.

  17. Modelling a Peroxidase-based Optical Biosensor

    Science.gov (United States)

    Baronas, Romas; Gaidamauskaite, Evelina; Kulys, Juozas

    2007-01-01

    The response of a peroxidase-based optical biosensor was modelled digitally. A mathematical model of the optical biosensor is based on a system of non-linear reaction-diffusion equations. The modelling biosensor comprises two compartments, an enzyme layer and an outer diffusion layer. The digital simulation was carried out using finite difference technique. The influence of the substrate concentration as well as of the thickness of both the enzyme and diffusion layers on the biosensor response was investigated. Calculations showed complex kinetics of the biosensor response, especially at low concentrations of the peroxidase and of the hydrogen peroxide.

  18. Cell-Based Biosensors Principles and Applications

    CERN Document Server

    Wang, Ping

    2009-01-01

    Written by recognized experts the field, this leading-edge resource is the first book to systematically introduce the concept, technology, and development of cell-based biosensors. You find details on the latest cell-based biosensor models and novel micro-structure biosensor techniques. Taking an interdisciplinary approach, this unique volume presents the latest innovative applications of cell-based biosensors in a variety of biomedical fields. The book also explores future trends of cell-based biosensors, including integrated chips, nanotechnology and microfluidics. Over 140 illustrations hel

  19. Photonic Crystal Biosensor Based on Optical Surface Waves

    Directory of Open Access Journals (Sweden)

    Giovanni Dietler

    2013-02-01

    Full Text Available A label-free biosensor device based on registration of photonic crystal surface waves is described. Angular interrogation of the optical surface wave resonance is used to detect changes in the thickness of an adsorbed layer, while an additional simultaneous detection of the critical angle of total internal reflection provides independent data of the liquid refractive index. The abilities of the device are demonstrated by measuring of biotin molecule binding to a streptavidin monolayer, and by measuring association and dissociation kinetics of immunoglobulin G proteins. Additionally, deposition of PSS / PAH polyelectrolytes is recorded in situ resulting calculation of PSS and PAH monolayer thicknesses separately.

  20. Computational Human Performance Modeling For Alarm System Design

    Energy Technology Data Exchange (ETDEWEB)

    Jacques Hugo

    2012-07-01

    The introduction of new technologies like adaptive automation systems and advanced alarms processing and presentation techniques in nuclear power plants is already having an impact on the safety and effectiveness of plant operations and also the role of the control room operator. This impact is expected to escalate dramatically as more and more nuclear power utilities embark on upgrade projects in order to extend the lifetime of their plants. One of the most visible impacts in control rooms will be the need to replace aging alarm systems. Because most of these alarm systems use obsolete technologies, the methods, techniques and tools that were used to design the previous generation of alarm system designs are no longer effective and need to be updated. The same applies to the need to analyze and redefine operators’ alarm handling tasks. In the past, methods for analyzing human tasks and workload have relied on crude, paper-based methods that often lacked traceability. New approaches are needed to allow analysts to model and represent the new concepts of alarm operation and human-system interaction. State-of-the-art task simulation tools are now available that offer a cost-effective and efficient method for examining the effect of operator performance in different conditions and operational scenarios. A discrete event simulation system was used by human factors researchers at the Idaho National Laboratory to develop a generic alarm handling model to examine the effect of operator performance with simulated modern alarm system. It allowed analysts to evaluate alarm generation patterns as well as critical task times and human workload predicted by the system.

  1. Trends in Protein-Based Biosensor Assemblies for Drug Screening and Pharmaceutical Kinetic Studies

    Directory of Open Access Journals (Sweden)

    Ana M. Gonçalves

    2014-08-01

    Full Text Available The selection of natural and chemical compounds for potential applications in new pharmaceutical formulations constitutes a time-consuming procedure in drug screening. To overcome this issue, new devices called biosensors, have already demonstrated their versatility and capacity for routine clinical diagnosis. Designed to perform analytical analysis for the detection of a particular analyte, biosensors based on the coupling of proteins to amperometric and optical devices have shown the appropriate selectivity, sensibility and accuracy. During the last years, the exponential demand for pharmacokinetic studies in the early phases of drug development, along with the need of lower molecular weight detection, have led to new biosensor structure materials with innovative immobilization strategies. The result has been the development of smaller, more reproducible biosensors with lower detection limits, and with a drastic reduction in the required sample volumes. Therefore in order to describe the main achievements in biosensor fields, the present review has the main aim of summarizing the essential strategies used to generate these specific devices, that can provide, under physiological conditions, a credible molecule profile and assess specific pharmacokinetic parameters.

  2. 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

  3. Design of SMART alarm system using main memory database

    International Nuclear Information System (INIS)

    To achieve design goal of SMART alarm system, first of all we have to decide on how to handle and manage alarm information and how to use database. So this paper analyses concepts and deficiencies of main memory database applied in real time system. And this paper sets up structure and processing principles of main memory database using nonvolatile memory such as flash memory and develops recovery strategy and process board structures using these. Therefore this paper shows design of SMART alarm system is suited functions and requirements

  4. A microfluidic paper-based electrochemical biosensor array for multiplexed detection of metabolic biomarkers

    OpenAIRE

    Chen Zhao, Martin M Thuo and Xinyu Liu

    2013-01-01

    Paper-based microfluidic devices have emerged as simple yet powerful platforms for performing low-cost analytical tests. This paper reports a microfluidic paper-based electrochemical biosensor array for multiplexed detection of physiologically relevant metabolic biomarkers. Different from existing paper-based electrochemical devices, our device includes an array of eight electrochemical sensors and utilizes a handheld custom-made electrochemical reader (potentiostat) for signal readout. The b...

  5. Enzyme conductometric biosensor for maltose determination

    Directory of Open Access Journals (Sweden)

    Dzyadevych S. V.

    2009-08-01

    Full Text Available Aim. To develop enzyme conductometric biosensor for maltose determination. Methods. A conductometric transducer consisting of two gold pairs of electrodes was applied. Three-enzyme membrane (glucose oxidase, mutarotase, -glucosidase immobilized on the surface of the conductometric transducer was used as a bioselective element. Results. A linear range of maltose conductometric biosensor was from 0,002 mM to 1 mM for glucose and maltose detection. The time of maltose analysis in solution was 1–2 minutes. The dependence of biosensor responses to substrate on pH, ionic strength, and buffer capacity of work solution was studied. The data of biosensor selectivity are presented. The developed conductometric biosensor is characterized by high operational stability and signal reproducibility. Conclusion. The enzyme conductometric biosensor for maltose determination has been developed. The analytical characteristics of the maltose biosensor were investigated. The proposed method could be used in food industry to control and optimize production.

  6. Biosensors and their applications - A review.

    Science.gov (United States)

    Mehrotra, Parikha

    2016-01-01

    The various types of biosensors such as enzyme-based, tissue-based, immunosensors, DNA biosensors, thermal and piezoelectric biosensors have been deliberated here to highlight their indispensable applications in multitudinous fields. Some of the popular fields implementing the use of biosensors are food industry to keep a check on its quality and safety, to help distinguish between the natural and artificial; in the fermentation industry and in the saccharification process to detect precise glucose concentrations; in metabolic engineering to enable in vivo monitoring of cellular metabolism. Biosensors and their role in medical science including early stage detection of human interleukin-10 causing heart diseases, rapid detection of human papilloma virus, etc. are important aspects. Fluorescent biosensors play a vital role in drug discovery and in cancer. Biosensor applications are prevalent in the plant biology sector to find out the missing links required in metabolic processes. Other applications are involved in defence, clinical sector, and for marine applications. PMID:27195214

  7. A novel wireless Love wave biosensor platform for multifunctional detection

    Science.gov (United States)

    Song, Taehyeon; Nam, Minwoo; Song, SeungYeon; Yoon, Hyun C.; Lee, Keekeun

    2011-02-01

    This paper presents a novel wireless Love wave biosensor platform for multi-functional detection. A 440MHz wireless and surface acoustic wave (SAW)-based biosensor was developed on a 41° YX LiNbO3 piezoelectric substrate for the simultaneous detection of Anti- Dinitrophenyl-KLH (anti-DNP) immunoglobulin G (IgG). The developed biosensor was composed of a SAW reflective delay lines structured by an interdigital transducer (IDT), shorted grating reflectors, poly(methyl-methacrylate) (PMMA) layer and two sensitive films (Cr/Au). The PMMA was used for the waveguide layer. Coupling of mode (COM) modeling was conducted to determine the optimal device parameters prior to fabrication. The fabricated devices were wirelessly characterized by using the network analyzer as the reader unit. The binding of anti-DNP to DNP receptor molecules induced a change in phase shifts of the original reflection peaks due to a mass loading effect. The phase shifts increased linearly with increasing anti-DNP concentration. The measured reflective coefficient S11 in the time domain showed high signal/noise (S/N) ratio, small signal attenuation, and few spurious peaks. The time positions of the reflection peaks were well matched with the predicted values from the simulation. The obtained sensitivity was 167.9°/μg/ml and 44.8°/ μg/ml for the 1st and the 2nd sensing area, respectively.

  8. 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.

  9. A WSN-Based Intrusion Alarm System to Improve Safety in Road Work Zones

    Directory of Open Access Journals (Sweden)

    Jose Martin

    2016-01-01

    Full Text Available Road traffic accidents are one of the main causes of death and disability worldwide. Workers responsible for maintaining and repairing roadways are especially prone to suffer these events, given their exceptional exposure to traffic. Since these actuations usually coexist with regular traffic, an errant driver can easily intrude the work area and provoke a collision. Some authors have proposed mechanisms aimed at detecting breaches in the work zone perimeter and alerting workers, which are collectively called intrusion alarm systems. However, they have several limitations and have not yet fulfilled the necessities of these scenarios. In this paper, we propose a new intrusion alarm system based on a Wireless Sensor Network (WSN. Our system is comprised of two main elements: vehicle detectors that form a virtual barrier and detect perimeter breaches by means of an ultrasonic beam and individual warning devices that transmit alerts to the workers. All these elements have a wireless communication interface and form a network that covers the whole work area. This network is in charge of transmitting and routing the alarms and coordinates the behavior of the system. We have tested our solution under real conditions with satisfactory results.

  10. Toxicity assessment using different bioassays and microbial biosensors.

    Science.gov (United States)

    Hassan, Sedky H A; Van Ginkel, Steven W; Hussein, Mohamed A M; Abskharon, Romany; Oh, Sang-Eun

    2016-01-01

    Toxicity assessment of water streams, wastewater, and contaminated sediments, is a very important part of environmental pollution monitoring. Evaluation of biological effects using a rapid, sensitive and cost effective method can indicate specific information on ecotoxicity assessment. Recently, different biological assays for toxicity assessment based on higher and lower organisms such as fish, invertebrates, plants and algal cells, and microbial bioassays have been used. This review focuses on microbial biosensors as an analytical device for environmental, food, and biomedical applications. Different techniques which are commonly used in microbial biosensing include amperometry, potentiometry, conductometry, voltammetry, microbial fuel cells, fluorescence, bioluminescence, and colorimetry. Examples of the use of different microbial biosensors in assessing a variety of environments are summarized. PMID:27071051

  11. Characterization of an hrp-aox-polyaniline-graphite composite biosensor

    Directory of Open Access Journals (Sweden)

    Ana Carolina O. Santana

    2014-12-01

    Full Text Available Nowadays there is an increasing demand to develop new and robust biosensors in order to detect low concentrations of different chemicals, in practical and small devices, giving fast and confident responses. The electrode material was a polyaniline-graphite-epoxy composite (PANI/GEC. Alcohol oxidase (AOX and horseradish peroxidase (HRP enzymes were immobilized and the responses were tested by cyclic voltammetry. The conductivities for the composites of graphite/polyaniline were determined. The cyclic voltammograms allowed detecting ethanol in pure diluted samples in a range from 0.036 to 2.62 M. Differential scanning calorimetry (DSC and thermal gravimetry analysis (TGA were used to verify the thermal characteristics of the composites (0, 10, 20, 30 and 100 % of graphite. The Imax value was determined for the dual enzyme biosensor (0.0724 mA, and the Kapp m  as 1.41 M (with R2 =0.9912.

  12. A magnetic biosensor system for detection of E. coli

    KAUST Repository

    Li, Fuquan

    2013-07-01

    This work describes a device for detecting E. coli bacteria by manipulating superparamagnetic beads to a sensing area and immobilizing them in a trapping well. The trapping well replaces the biochemical immobilization layer, which is commonly used in magnetic biosensor systems. A concept exploiting the volume difference between bare magnetic beads and magnetic bead-bioanalyte compounds is utilized to detect E. coli bacteria. Trapped beads are detected by the help of a tunnel magneto-resistive sensor. Frequency modulation is employed, in order to increase the signal-to-noise ratio, enabling the detection of individual superparamagnetic beads of 2.8 μm in diameter. Replacing the biochemical immobilization layer by the trapping well greatly simplifies the detection process. After applying the mixture of E. coli and magnetic beads to the biosensor system, bacteria detection is achieved in a single step, within a few minutes. © 2013 IEEE.

  13. New ways to develop biosensors towards addressing practical problems

    Science.gov (United States)

    Starodub, N. F.

    2013-11-01

    The main modern approaches which were realized at the development of new generation of biosensors intended for application in field of diagnostics, food quality control and environmental monitoring are presented. The main attention was paid to creation of the multi-parametrical and multi-functional enzymatic and immune biosensors which were realized for the complex diagnostics of diabetes, autoimmune state and for the control of process of sugar production. The label-free bioaffine devices based on the nano-porouse silicon (NPS) with the registration of specific formed signal by chemiluminescence (ChL) and photoresistivity and intended for the determination mycotoxins and diagnostics of retroviral bovine leukemia (RBL) are analyzed too. Improving of ion sensitive field effect transistors (ISFETs) through changing silicon nitride on the cerium oxide is discussed as perspective approach in case of micotoxins and Salmonella control. In the conclusion the possibility to replace biological sensitive elements by artificial ones is considered.

  14. Alarm!!! A UFO inside the heart.

    Science.gov (United States)

    Santoro, Giuseppe; Castaldi, Biagio; Iacono, Carola; Giugno, Luca; Gaio, Gianpiero; Russo, Maria G

    2012-10-01

    An 8-year-old asymptomatic child was referred for surgical repair of coronary sinus atrial septal defect resulting in significant left-to-right shunt and right chamber volume overload. The septal fenestration was located near to its drainage site into the right atrium. Due to this seemingly favourable anatomy, transcatheter closure of the septal defect was performed using an Amplatzer Septal Occluder device. The echocardiographic postprocedural evaluation imaged the occluding device almost perpendicular to the atrial septum, seemingly floating above the mitral valve orifice, like an alien spaceship inside the heart. PMID:22955207

  15. Alarm!!! A UFO inside the heart.

    Science.gov (United States)

    Santoro, Giuseppe; Castaldi, Biagio; Iacono, Carola; Giugno, Luca; Gaio, Gianpiero; Russo, Maria G

    2012-10-01

    An 8-year-old asymptomatic child was referred for surgical repair of coronary sinus atrial septal defect resulting in significant left-to-right shunt and right chamber volume overload. The septal fenestration was located near to its drainage site into the right atrium. Due to this seemingly favourable anatomy, transcatheter closure of the septal defect was performed using an Amplatzer Septal Occluder device. The echocardiographic postprocedural evaluation imaged the occluding device almost perpendicular to the atrial septum, seemingly floating above the mitral valve orifice, like an alien spaceship inside the heart.

  16. rf duress alarms: market survey and preliminary characterization

    Energy Technology Data Exchange (ETDEWEB)

    Draper, B.L.

    1979-05-01

    This report represents the first phase of the duress alarm studies. Presented here are the results of an extensive market survey and some preliminary observations on the effectiveness of many system components.

  17. ARC Code TI: Optimal Alarm System Design and Implementation

    Data.gov (United States)

    National Aeronautics and Space Administration — An optimal alarm system can robustly predict a level-crossing event that is specified over a fixed prediction horizon. The code contained in this packages provides...

  18. Wireless intelligent alarm technology with pyroelectric infrared sensor

    Science.gov (United States)

    Chen, Xiao

    2009-07-01

    Aiming at the defects of monitoring conducted by man in the conventional practice, we study the passive intelligent automatic alarm technology based on the pyroelectric infrared sensor and wireless communication technology. The designed passive infrared wireless alarm is composed of pyroelectric infrared sensors, infrared special chip BISS0001 and their peripheral circuits. When someone enters into the detecting and monitoring range, the alarm will detect the infrared ray of the human radiation by the contactless form and detect the signals of circuit output. Then it translates them into low frequency signals relative with human sports speed, distance and direction, produce corresponding output signals through amplifying by the back state controller, switch on the work power of the wireless transmitting circuit and make it emit the alarm signals. The system enhances the monitoring level and effects and possesses many advantages such as wide detecting range, long detecting distance and high reliability.

  19. A weighted dissimilarity index to isolate faults during alarm floods

    CERN Document Server

    Charbonnier, S; Gayet, P

    2015-01-01

    A fault-isolation method based on pattern matching using the alarm lists raised by the SCADA system during an alarm flood is proposed. A training set composed of faults is used to create fault templates. Alarm vectors generated by unknown faults are classified by comparing them with the fault templates using an original weighted dissimilarity index that increases the influence of the few alarms relevant to diagnose the fault. Different decision strategies are proposed to support the operator in his decision making. The performances are evaluated on two sets of data: an artificial set and a set obtained from a highly realistic simulator of the CERN Large Hadron Collider process connected to the real CERN SCADA system.

  20. Onsite Portable Alarm System - Its Merit and Application

    Science.gov (United States)

    Saita, J.; Sato, T.; Nakamura, Y.

    2007-12-01

    Recently an existence of the earthquake early warning system (EEWS) becomes popular. In general, the EEWS will be installed in a fixed observation site and it may consist of several separated components such as a sensing portion, A/D converter, an information processing potion and so on. The processed information for warning may be transmitted to network via fixed communication line, and therefore this kind of alarm system is called as Network Alarm System. On the other hand, after the severe earthquake damage, it is very important to save the disaster victims immediately. These rescue staffs are also under the risk of aftershocks and need a local alarm not depending on the network, so this kind of alarm can be called as Onsite Alarm. But the common early warning system is too complex to set onsite temporary, and even if possible to install, the alarm is too late to receive at the epicentral area. However, the new generation earthquake early warning system FREQL can issue the P wave alarm by minimum 0.2 seconds after P wave detection. And FREQL is characterized as the unique all-in-one seismometer with power unit. At the time of the 2004 Niigata-Ken-Chuetsu earthquake, a land slide attacked a car just passing. A hyper rescue team of Tokyo Fire Department pulled the survivor, one baby, from the land slide area. During their activity the rescue team was exposed to the risk of secondary hazards caused by the aftershocks. It was clear that it is necessary to use a portable warning system to issue the onsite P wave alarm. Because FREQL was originally developed as portable equipment, Tokyo Fire Department asked us to modify it to the portable equipment with the loud sound and the light signal. In this moment, this portable FREQL has equipped in nation wide. When the hyper rescue team of Tokyo Fire Department was sent to Pakistan as a task force for rescue work of the 2005 Pakistan earthquake, the portable FREQL was used as important onsite portable warning system and P

  1. DESIGN OF INTEGRATING WAVEGUIDE BIOSENSOR

    Science.gov (United States)

    The Integrating Waveguide Biosensor allows for rapid and sensitive detection of pathogenic agents, cells and proteins via immunoassay or PCR products. The analytes are captured on the surface of the waveguide and then tagged with fluorescent labels. The waveguides are illuminated by excitation light...

  2. 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 antib

  3. Chimpanzee Alarm Call Production Meets Key Criteria for Intentionality

    OpenAIRE

    Schel, Anne Marijke; Simon W Townsend; Machanda, Zarin; Zuberbühler, Klaus; Slocombe, Katie E.

    2013-01-01

    Determining the intentionality of primate communication is critical to understanding the evolution of human language. Although intentional signalling has been claimed for some great ape gestural signals, comparable evidence is currently lacking for their vocal signals. We presented wild chimpanzees with a python model and found that two of three alarm call types exhibited characteristics previously used to argue for intentionality in gestural communication. These alarm calls were: (i) sociall...

  4. Chimpanzee alarm call production meets key criteria for intentionality

    OpenAIRE

    Schel, Anne M.; Simon W Townsend; Machanda, Zarin; Zuberbühler, Klaus; Slocombe, Katie E.

    2013-01-01

    Determining the intentionality of primate communication is critical to understanding the evolution of human language. Although intentional signalling has been claimed for some great ape gestural signals, comparable evidence is currently lacking for their vocal signals. We presented wild chimpanzees with a python model and found that two of three alarm call types exhibited characteristics previously used to argue for intentionality in gestural communication. These alarm calls were: (i) sociall...

  5. An alarm processing system for a nuclear power plant using artificial intelligence techniques

    International Nuclear Information System (INIS)

    This paper reports on an alarm processing system (APS) developed that uses artificial intelligence techniques to help operators to make decisions. Alarms in nuclear power plants are classified into generalized and special alarms. Generalized alarms are further classified into global and local alarms. For each type of alarm, the specific processing rules are applied to filter and suppress unnecessary and potentially misleading alarms. The processing for the generalized alarms is based on model-based reasoning. The special alarms are processed by the cause-consequence check rules. The priorities of alarms are determined according to both the plant state and the consistencies among the alarms. This APS is built on a workstation using the Prolog language

  6. False-alarm characterization in hyperspectral gas-detection applications

    Science.gov (United States)

    DiPietro, Robert S.; Truslow, Eric; Manolakis, Dimitris G.; Golowich, Steven E.; Lockwood, Ronald B.

    2012-09-01

    Chemical cloud detection using long-wave infrared (LWIR) hyperspectral-imaging sensors has many civilian and military applications, including chemical warfare threat mitigation, environmental monitoring, and emergency response. Current capabilities are limited by variation in background clutter as opposed to the physics of photon detection, and this makes the statistical characterization of clutter and clutter-induced false alarms essential to the design of practical systems. In this exploratory work, we use hyperspectral data collected both on the ground and in the air to spectrally and spatially characterize false alarms. Focusing on two widely-used detectors, the matched filter (MF) and the adaptive cosine estimator (ACE), we compare empirical false-alarm rates to their theoretical counterparts - detector output under Gaussian, t and t-mixture distributed data - and show that these models often underestimate false-alarm rates. Next, we threshold real detection maps and show that true detections and false alarms often exhibit very different spatial behavior. To exploit this difference and understand how spatial processing affects performance, the spatial behavior of false alarms must be understood. We take a first step in this direction by showing that, although the behavior may `look' quite random, it is not well captured by the complete-spatial-randomness model. Finally, we describe how our findings impact the design of real detection systems.

  7. Perimeter security alarm system based on fiber Bragg grating

    Science.gov (United States)

    Zhang, Cui; Wang, Lixin

    2010-11-01

    With the development of the society and economy and the improvement of living standards, people need more and more pressing security. Perimeter security alarm system is widely regarded as the first line of defense. A highly sensitive Fiber Bragg grating (FBG) vibration sensor based on the theory of the string vibration, combined with neural network adaptive dynamic programming algorithm for the perimeter security alarm system make the detection intelligently. Intelligent information processing unit identify the true cause of the vibration of the invasion or the natural environment by analyzing the frequency of vibration signals, energy, amplitude and duration. Compared with traditional perimeter security alarm systems, such as infrared perimeter security system and electric fence system, FBG perimeter security alarm system takes outdoor passive structures, free of electromagnetic interference, transmission distance through optical fiber can be as long as 20 km It is able to detect the location of event within short period of time (high-speed response, less than 3 second).This system can locate the fiber cable's breaking sites and alarm automatically if the cable were be cut. And the system can prevent effectively the false alarm from small animals, birds, strong wind, scattering things, snowfalls and vibration of sensor line itself. It can also be integrated into other security systems. This system can be widely used in variety fields such as military bases, nuclear sites, airports, warehouses, prisons, residence community etc. It will be a new force of perimeter security technology.

  8. Nanoelectronic biosensors based on CVD grown graphene

    Science.gov (United States)

    Huang, Yinxi; Dong, Xiaochen; Shi, Yumeng; Li, Chang Ming; Li, Lain-Jong; Chen, Peng

    2010-08-01

    Graphene, a single-atom-thick and two-dimensional carbon material, has attracted great attention recently. Because of its unique electrical, physical, and optical properties, graphene has great potential to be a novel alternative to carbon nanotubes in biosensing. We demonstrate the use of large-sized CVD grown graphene films configured as field-effect transistors for real-time biomolecular sensing. Glucose or glutamate molecules were detected by the conductance change of the graphene transistor as the molecules are oxidized by the specific redox enzyme (glucose oxidase or glutamic dehydrogenase) functionalized onto the graphene film. This study indicates that graphene is a promising candidate for the development of real-time nanoelectronic biosensors.Graphene, a single-atom-thick and two-dimensional carbon material, has attracted great attention recently. Because of its unique electrical, physical, and optical properties, graphene has great potential to be a novel alternative to carbon nanotubes in biosensing. We demonstrate the use of large-sized CVD grown graphene films configured as field-effect transistors for real-time biomolecular sensing. Glucose or glutamate molecules were detected by the conductance change of the graphene transistor as the molecules are oxidized by the specific redox enzyme (glucose oxidase or glutamic dehydrogenase) functionalized onto the graphene film. This study indicates that graphene is a promising candidate for the development of real-time nanoelectronic biosensors. Electronic supplementary information (ESI) available: AFM images of graphene film before and after functionalization, transfer curves of graphene after every step, SEM image of CNT-net, and detection results using CNT-net devices. See DOI: 10.1039/c0nr00142b

  9. Numerical simulation on development of a SAW based biosensor

    Science.gov (United States)

    Ten, S. T.; Hashim, U.; Sudin, A.; Arshad, M. K. Md.; Liu, W. W.; Foo, K. L.; Voon, C. H.; Wee, F. H.; Lee, Y. S.; Salleh, N. H. M.; Nazwa, T.

    2016-07-01

    Surface acoustic waves can be generated at the free surface of an elastic solid. For this property, surface acoustic based devices were initially developed for the telecommunication purpose such as signal filters and resonators. The acoustic energy is strongly confined on the surface of the surface acoustic waves (SAW) based devices and consequent their ultra-sensitivity to the surface perturbation. This has made SAW permits the highly sensitive detection of utterly diminutive charges on the surface. Hence, SAW based devices have been modified to be sensors for the mass loading effect on its surface and this is perfectly for biosensor development. There have been a lot of complicated theoretical models for the SAW devices development since 1960 as signal filters and resonators such as from delta function model, equivalent circuit model, to the current SAW models such as coupling-of-modes (COM) model, P-matrix model and Computer Simulation Technology Studio Suite (CST). However, these models are more tailored for the telecommunication application purposes and very complex. Thus, this paper presents the finite element analysis (FEA) modeling, COMSOL Multiphysics which is used to study the mass loading effect on SAW which will be used as biosensor. This study managed to simulate the mass loading sensitivity of 8.71×107 kHz/g mm-2.

  10. Integrated optical biosensor for rapid detection of bacteria

    Science.gov (United States)

    Mathesz, Anna; Valkai, Sándor; Újvárosy, Attila; Aekbote, Badri; Sipos, Orsolya; Stercz, Balázs; Kocsis, Béla; Szabó, Dóra; Dér, András

    2016-02-01

    In medical diagnostics, rapid detection of pathogenic bacteria from body fluids is one of the basic issues. Most state-of-the-art methods require optical labeling, increasing the complexity, duration and cost of the analysis. Therefore, there is a strong need for developing selective sensory devices based on label-free techniques, in order to increase the speed, and reduce the cost of detection. In a recent paper, we have shown that an integrated optical Mach-Zehnder interferometer, a highly sensitive all-optical device made of a cheap photopolymer, can be used as a powerful lab-on-a-chip tool for specific, labelfree detection of proteins. By proper modifications of this technique, our interferometric biosensor was combined with a microfluidic system allowing the rapid and specific detection of bacteria from solutions, having the surface of the sensor functionalized by bacterium-specific antibodies. The experiments proved that the biosensor was able to detect Escherichia coli bacteria at concentrations of 106 cfu/ml within a few minutes, that makes our device an appropriate tool for fast, label-free detection of bacteria from body fluids such as urine or sputum. On the other hand, possible applications of the device may not be restricted to medical microbiology, since bacterial identification is an important task in microbial forensics, criminal investigations, bio-terrorism threats and in environmental studies, as well.

  11. Polystyrene Based SPR Biosensor Chip for Use in Immunoassay

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Biosensors are widely used in immunoassay.The biosensor chip carries a receptor which is used in immunoassay and the chip properties have an important influence on the detecting sensitivity of the biosensor.This paper describes a polystyrene-based biosensor chip developed and used as part of a surface plasmon resonance (SPR) biosensor.The SPR biosensor has a much higher detecting sensitivity than enzyme-linked immunoserbent assay (ELISA).

  12. Alarm pheromone processing in the ant brain: an evolutionary perspective

    Directory of Open Access Journals (Sweden)

    Makoto Mizunami

    2010-06-01

    Full Text Available Social insects exhibit sophisticated communication by means of pheromones, one example of which is the use of alarm pheromones to alert nestmates for colony defense. We review recent advances in the understanding of the processing of alarm pheromone information in the ant brain. We found that information about formic acid and n-undecane, alarm pheromone components, is processed in a set of specific glomeruli in the antennal lobe of the ant Camponotus obscuripes. Alarm pheromone information is then transmitted, via projection neurons, to the lateral horn and the calyces of the mushroom body of the protocerebrum. In the lateral horn, we found a specific area where terminal boutons of alarm pheromone-sensitive projection neurons are more densely distributed than in the rest of the lateral horn. Some neurons in the protocerebrum responded specifically to formic acid or n-undecane and they may participate in the control of behavioral responses to each pheromone component. Other neurons, especially those originating from the mushroom body lobe, responded also to non-pheromonal odors and may play roles in integration of pheromonal and non-pheromonal signals. We found that a class of neurons receive inputs in the lateral horn and the mushroom body lobe and terminate in a variety of premotor areas. These neurons may participate in the control of aggressive behavior, which is sensitized by alarm pheromones and is triggered by non-pheromonal sensory stimuli associated with a potential enemy. We propose that the alarm pheromone processing system has evolved by differentiation of a part of general odor processing system.

  13. Attributions of cancer 'alarm' symptoms in a community sample.

    Directory of Open Access Journals (Sweden)

    Katriina L Whitaker

    Full Text Available BACKGROUND: Attribution of early cancer symptoms to a non-serious cause may lead to longer diagnostic intervals. We investigated attributions of potential cancer 'alarm' and non-alarm symptoms experienced in everyday life in a community sample of adults, without mention of a cancer context. METHODS: A questionnaire was mailed to 4858 adults (≥50 years old, no cancer diagnosis through primary care, asking about symptom experiences in the past 3 months. The word cancer was not mentioned. Target 'alarm' symptoms, publicised by Cancer Research UK, were embedded in a longer symptom list. For each symptom experienced, respondents were asked for their attribution ('what do you think caused it', concern about seriousness ('not at all' to 'extremely', and help-seeking ('did you contact a doctor about it': Yes/No. RESULTS: The response rate was 35% (n = 1724. Over half the respondents (915/1724; 53% had experienced an 'alarm' symptom, and 20 (2% cited cancer as a possible cause. Cancer attributions were highest for 'unexplained lump'; 7% (6/87. Cancer attributions were lowest for 'unexplained weight loss' (0/47. A higher proportion (375/1638; 23% were concerned their symptom might be 'serious', ranging from 12% (13/112 for change in a mole to 41% (100/247 for unexplained pain. Just over half had contacted their doctor about their symptom (59%, although this varied by symptom. Alarm symptoms were appraised as more serious than non-alarm symptoms, and were more likely to trigger help-seeking. CONCLUSIONS: Consistent with retrospective reports from cancer patients, 'alarm' symptoms experienced in daily life were rarely attributed to cancer. These results have implications for understanding how people appraise and act on symptoms that could be early warning signs of cancer.

  14. A MEMS Dielectric Affinity Glucose Biosensor.

    Science.gov (United States)

    Huang, Xian; Li, Siqi; Davis, Erin; Li, Dachao; Wang, Qian; Lin, Qiao

    2013-06-20

    Continuous glucose monitoring (CGM) sensors based on affinity detection are desirable for long-term and stable glucose management. However, most affinity sensors contain mechanical moving structures and complex design in sensor actuation and signal readout, limiting their reliability in subcutaneously implantable glucose detection. We have previously demonstrated a proof-of-concept dielectric glucose sensor that measured pre-mixed glucose-sensitive polymer solutions at various glucose concentrations. This sensor features simplicity in sensor design, and possesses high specificity and accuracy in glucose detection. However, lack of glucose diffusion passage, this device is unable to fulfill real-time in-vivo monitoring. As a major improvement to this device, we present in this paper a fully implantable MEMS dielectric affinity glucose biosensor that contains a perforated electrode embedded in a suspended diaphragm. This capacitive-based sensor contains no moving parts, and enables glucose diffusion and real-time monitoring. The experimental results indicate that this sensor can detect glucose solutions at physiological concentrations and possesses good reversibility and reliability. This sensor has a time constant to glucose concentration change at approximately 3 min, which is comparable to commercial systems. The sensor has potential applications in fully implantable CGM that require excellent long-term stability and reliability. PMID:24511215

  15. Zinc Oxide Nanostructured Biosensor for Glucose Detection

    Institute of Scientific and Technical Information of China (English)

    X. W.Sun; J.X. Wang; A. Wei

    2008-01-01

    Zinc oxide (ZnO) nanocombs were fabricated by vapor phase transport, and nanorods and hierarchical nanodisk structures by aqueous thermal decomposition. Glucose biosensors were constructed using these ZnO nanostructures as supporting materials for glucose oxidase (GOx) loading. These ZnO glucose biosensors showed a high sensitivity for glucose detection and high affinity of GOx to glucose as well as the low detection limit. The results demonstrate that ZnO nanostructures have potential applications in biosensors.

  16. Label-Free Biosensors for Cell Biology

    OpenAIRE

    Ye Fang

    2011-01-01

    Label-free biosensors for studying cell biology have finally come of age. Recent developments have advanced the biosensors from low throughput and high maintenance research tools to high throughput and low maintenance screening platforms. In parallel, the biosensors have evolved from an analytical tool solely for molecular interaction analysis to powerful platforms for studying cell biology at the whole cell level. This paper presents historical development, detection principles, and applicat...

  17. Label-Free Biosensors for Cell Biology

    Directory of Open Access Journals (Sweden)

    Ye Fang

    2011-01-01

    Full Text Available Label-free biosensors for studying cell biology have finally come of age. Recent developments have advanced the biosensors from low throughput and high maintenance research tools to high throughput and low maintenance screening platforms. In parallel, the biosensors have evolved from an analytical tool solely for molecular interaction analysis to powerful platforms for studying cell biology at the whole cell level. This paper presents historical development, detection principles, and applications in cell biology of label-free biosensors. Future perspectives are also discussed.

  18. Reducing SCADA System Nuisance Alarms in the Water Industry in Northern Ireland.

    Science.gov (United States)

    O'Donoghue, Nigel; Phillips, Debra H; Nicell, Ciaran

    2015-08-01

    The advancement of telemetry control for the water industry has increased the difficulty of managing large volumes of nuisance alarms (i.e., alarms that do not require a response). The aim of this study was to identify and reduce the number of nuisance alarms that occur for Northern Ireland (NI) Water by carrying out alarm duration analysis to determine the appropriate length of persistence (an advanced alarm management tool) that could be applied. All data were extracted from TelemWeb (NI Water's telemetry monitoring system) and analyzed in Excel. Over a 6-week period, an average of 40 000 alarms occurred per week. The alarm duration analysis, which has never been implemented before by NI Water, found that an average of 57% of NI Water alarms had a duration of <5 minutes. Applying 5-minute persistence, therefore, could prevent an average 26 816 nuisance alarms per week. Most of these alarms were from wastewater assets. PMID:26237691

  19. FAULT DIAGNOSIS WITH MULTI-STATE ALARMS IN A NUCLEAR POWER CONTROL SIMULATOR

    Energy Technology Data Exchange (ETDEWEB)

    Austin Ragsdale; Roger Lew; Brian P. Dyre; Ronald L. Boring

    2012-10-01

    This research addresses how alarm systems can increase operator performance within nuclear power plant operations. The experiment examined the effect of two types of alarm systems (two-state and three-state alarms) on alarm compliance and diagnosis for two types of faults differing in complexity. We hypothesized three-state alarms would improve performance in alarm recognition and fault diagnoses over that of two-state alarms. We used sensitivity and criterion based on Signal Detection Theory to measure performance. We further hypothesized that operator trust would be highest when using three-state alarms. The findings from this research showed participants performed better and had more trust in three-state alarms compared to two-state alarms. Furthermore, these findings have significant theoretical implications and practical applications as they apply to improving the efficiency and effectiveness of nuclear power plant operations.

  20. Applications of polymers for biomolecule immobilization in electrochemical biosensors

    International Nuclear Information System (INIS)

    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

  1. Use of biosensors for the detection of marine toxins.

    Science.gov (United States)

    McPartlin, Daniel A; Lochhead, Michael J; Connell, Laurie B; Doucette, Gregory J; O'Kennedy, Richard J

    2016-06-30

    Increasing occurrences of harmful algal blooms (HABs) in the ocean are a major concern for countries around the globe, and with strong links between HABs and climate change and eutrophication, the occurrences are only set to increase. Of particular concern with regard to HABs is the presence of toxin-producing algae. Six major marine biotoxin groups are associated with HABs. Ingestion of such toxins via contaminated shellfish, fish, or other potential vectors, can lead to intoxication syndromes with moderate to severe symptoms, including death in extreme cases. There are also major economic implications associated with the diverse effects of marine biotoxins and HABs. Thus, effective monitoring programmes are required to manage and mitigate their detrimental global effect. However, currently legislated detection methods are labour-intensive, expensive and relatively slow. The growing field of biosensor diagnostic devices is an exciting area that has the potential to produce robust, easy-to-use, cost-effective, rapid and accurate detection methods for marine biotoxins and HABs. This review discusses recently developed biosensor assays that target marine biotoxins and their microbial producers, both in harvested fish/shellfish samples and in the open ocean. The effective deployment of such biosensor platforms could address the pressing need for improved monitoring of HABs and marine biotoxins, and could help to reduce their global economic impact.

  2. Surface Modification on Acoustic Wave Biosensors for Enhanced Specificity

    Directory of Open Access Journals (Sweden)

    Nathan D. Gallant

    2012-09-01

    Full Text Available Changes in mass loading on the surface of acoustic biosensors result in output frequency shifts which provide precise measurements of analytes. Therefore, to detect a particular biomarker, the sensor delay path must be judiciously designed to maximize sensitivity and specificity. B-cell lymphoma 2 protein (Bcl-2 found in urine is under investigation as a biomarker for non-invasive early detection of ovarian cancer. In this study, surface chemistry and biofunctionalization approaches were evaluated for their effectiveness in presenting antibodies for Bcl-2 capture while minimizing non-specific protein adsorption. The optimal combination of sequentially adsorbing protein A/G, anti-Bcl-2 IgG and Pluronic F127 onto a hydrophobic surface provided the greatest signal-to-noise ratio and enabled the reliable detection of Bcl-2 concentrations below that previously identified for early stage ovarian cancer as characterized by a modified ELISA method. Finally, the optimal surface modification was applied to a prototype acoustic device and the frequency shift for a range of Bcl-2 concentration was quantified to demonstrate the effectiveness in surface acoustic wave (SAW-based detection applications. The surface functionalization approaches demonstrated here to specifically and sensitively detect Bcl-2 in a working ultrasonic MEMS biosensor prototype can easily be modified to detect additional biomarkers and enhance other acoustic biosensors.

  3. Use of biosensors for the detection of marine toxins.

    Science.gov (United States)

    McPartlin, Daniel A; Lochhead, Michael J; Connell, Laurie B; Doucette, Gregory J; O'Kennedy, Richard J

    2016-06-30

    Increasing occurrences of harmful algal blooms (HABs) in the ocean are a major concern for countries around the globe, and with strong links between HABs and climate change and eutrophication, the occurrences are only set to increase. Of particular concern with regard to HABs is the presence of toxin-producing algae. Six major marine biotoxin groups are associated with HABs. Ingestion of such toxins via contaminated shellfish, fish, or other potential vectors, can lead to intoxication syndromes with moderate to severe symptoms, including death in extreme cases. There are also major economic implications associated with the diverse effects of marine biotoxins and HABs. Thus, effective monitoring programmes are required to manage and mitigate their detrimental global effect. However, currently legislated detection methods are labour-intensive, expensive and relatively slow. The growing field of biosensor diagnostic devices is an exciting area that has the potential to produce robust, easy-to-use, cost-effective, rapid and accurate detection methods for marine biotoxins and HABs. This review discusses recently developed biosensor assays that target marine biotoxins and their microbial producers, both in harvested fish/shellfish samples and in the open ocean. The effective deployment of such biosensor platforms could address the pressing need for improved monitoring of HABs and marine biotoxins, and could help to reduce their global economic impact. PMID:27365035

  4. Alarm reduction with correlation analysis; Larmsanering genom korrelationsanalys

    Energy Technology Data Exchange (ETDEWEB)

    Bergquist, Tord; Ahnlund, Jonas; Johansson, Bjoern; Gaardman, Lennart; Raaberg, Martin [Lund Univ. (Sweden). Dept. of Information Technology

    2004-09-01

    This project's main interest is to improve the overall alarm situation in the control rooms. By doing so, the operators working environment is less overstrained, which simplifies the decision-making. According to a study of the British refinery industry, the operators make wrong decisions in four times out of ten due to badly tuned alarm systems, with heavy expenses as a result. Furthermore, a more efficiently alarm handling is estimated to decrease the production loss with between three and eight percent. This sounds, according to Swedish standards, maybe a bit extreme, but there is no doubt about the benefits of having a well-tuned alarm system. This project can be seen as an extension of 'General Methods for Alarm Reduction' (VARMEFORSK--835), where the process improvements were the result of suggestions tailored for every signal. Here, instead causal dependences in the process are examined. A method for this, specially designed to fit process signals, has been developed. It is called MLPC (Multiple Local Property Correlation) and could be seen as an unprejudiced way of increase the information value in the process. There are a number of ways to make use of the additional process understanding a correlation analysis provides. In the report some are mentioned, foremost aiming to improve the alarm situation for operators. Signals from two heating plants have been analyzed with MLPC. In simulations, with the use of the result from these analyses as a base, a large number of alarms have been successfully suppressed. The results have been studied by personal with process knowledge, and they are very positive to the use of MLPC and they express many benefits by the clarification of process relations. It was established in 'General Methods for Alarm Reduction' that low pass filter are superior to mean value filter and time delay when trying to suppress alarms. As a result, a module for signal processing has been developed. The main purpose is

  5. Wild birds learn to eavesdrop on heterospecific alarm calls.

    Science.gov (United States)

    Magrath, Robert D; Haff, Tonya M; McLachlan, Jessica R; Igic, Branislav

    2015-08-01

    Many vertebrates gain critical information about danger by eavesdropping on other species' alarm calls [1], providing an excellent context in which to study information flow among species in animal communities [2-4]. A fundamental but unresolved question is how individuals recognize other species' alarm calls. Although individuals respond to heterospecific calls that are acoustically similar to their own, alarms vary greatly among species, and eavesdropping probably also requires learning [1]. Surprisingly, however, we lack studies demonstrating such learning. Here, we show experimentally that individual wild superb fairy-wrens, Malurus cyaneus, can learn to recognize previously unfamiliar alarm calls. We trained individuals by broadcasting unfamiliar sounds while simultaneously presenting gliding predatory birds. Fairy-wrens in the experiment originally ignored these sounds, but most fled in response to the sounds after two days' training. The learned response was not due to increased responsiveness in general or to sensitization following repeated exposure and was independent of sound structure. Learning can therefore help explain the taxonomic diversity of eavesdropping and the refining of behavior to suit the local community. In combination with previous work on unfamiliar predator recognition (e.g., [5]), our results imply rapid spread of anti-predator behavior within wild populations and suggest methods for training captive-bred animals before release into the wild [6]. A remaining challenge is to assess the importance and consequences of direct association of unfamiliar sounds with predators, compared with social learning-such as associating unfamiliar sounds with conspecific alarms.

  6. Nuclear-power-plant perimeter-intrusion alarm systems

    Energy Technology Data Exchange (ETDEWEB)

    Halsey, D.J.

    1982-04-01

    Timely intercept of an intruder requires the examination of perimeter barriers and sensors in terms of reliable detection, immediate assessment and prompt response provisions. Perimeter security equipment and operations must at the same time meet the requirements of the Code of Federal Regulations, 10 CFR 73.55 with some attention to the performance and testing figures of Nuclear Regulatory Guide 5.44, Revision 2, May 1980. A baseline system is defined which recommends a general approach to implementing perimeter security elements: barriers, lighting, intrusion detection, alarm assessment. The baseline approach emphasizes cost/effectiveness achieved by detector layering and logic processing of alarm signals to produce reliable alarms and low nuisance alarm rates. A cost benefit of layering along with video assessment is reduction in operating expense. The concept of layering is also shown to minimize testing costs where detectability performance as suggested by Regulatory Guide 5.44 is to be performed. Synthesis of the perimeter intrusion alarm system and limited testing of CCTV and Video Motion Detectors (VMD), were performed at E-Systems, Greenville Division, Greenville, Texas during 1981.

  7. Nuclear-power-plant perimeter-intrusion alarm systems

    International Nuclear Information System (INIS)

    Timely intercept of an intruder requires the examination of perimeter barriers and sensors in terms of reliable detection, immediate assessment and prompt response provisions. Perimeter security equipment and operations must at the same time meet the requirements of the Code of Federal Regulations, 10 CFR 73.55 with some attention to the performance and testing figures of Nuclear Regulatory Guide 5.44, Revision 2, May 1980. A baseline system is defined which recommends a general approach to implementing perimeter security elements: barriers, lighting, intrusion detection, alarm assessment. The baseline approach emphasizes cost/effectiveness achieved by detector layering and logic processing of alarm signals to produce reliable alarms and low nuisance alarm rates. A cost benefit of layering along with video assessment is reduction in operating expense. The concept of layering is also shown to minimize testing costs where detectability performance as suggested by Regulatory Guide 5.44 is to be performed. Synthesis of the perimeter intrusion alarm system and limited testing of CCTV and Video Motion Detectors (VMD), were performed at E-Systems, Greenville Division, Greenville, Texas during 1981

  8. Role of Large Clinical Datasets From Physiologic Monitors in Improving the Safety of Clinical Alarm Systems and Methodological Considerations: A Case From Philips Monitors

    Science.gov (United States)

    Reed, Charles Calhoun; Staggers, Nancy

    2016-01-01

    Background Large datasets of the audit log of modern physiologic monitoring devices have rarely been used for predictive modeling, capturing unsafe practices, or guiding initiatives on alarm systems safety. Objective This paper (1) describes a large clinical dataset using the audit log of the physiologic monitors, (2) discusses benefits and challenges of using the audit log in identifying the most important alarm signals and improving the safety of clinical alarm systems, and (3) provides suggestions for presenting alarm data and improving the audit log of the physiologic monitors. Methods At a 20-bed transplant cardiac intensive care unit, alarm data recorded via the audit log of bedside monitors were retrieved from the server of the central station monitor. Results Benefits of the audit log are many. They include easily retrievable data at no cost, complete alarm records, easy capture of inconsistent and unsafe practices, and easy identification of bedside monitors missed from a unit change of alarm settings adjustments. Challenges in analyzing the audit log are related to the time-consuming processes of data cleaning and analysis, and limited storage and retrieval capabilities of the monitors. Conclusions The audit log is a function of current capabilities of the physiologic monitoring systems, monitor’s configuration, and alarm management practices by clinicians. Despite current challenges in data retrieval and analysis, large digitalized clinical datasets hold great promise in performance, safety, and quality improvement. Vendors, clinicians, researchers, and professional organizations should work closely to identify the most useful format and type of clinical data to expand medical devices’ log capacity. PMID:27694097

  9. Novel Polythiophenes for Biosensor Applications

    OpenAIRE

    Clayton, Kate

    2011-01-01

    The development of an enzyme biosensor employing a novel functionalised polythiophene matrix is presented. The research upon conducting polymer platforms for biological immobilisation is extensive but by no means exhaustive and therefore this investigation contributes to the field of glucose detection with covalently immobilised glucose oxidase upon novel copolymers of N-succinimido thiophene-3- acetate/3-methylthiophene (STA-MT), trans-3-(3-thienyl) acetic acid/3- methylthiophene (TTA-MT)...

  10. Improvements in electrochemical glucose biosensors

    OpenAIRE

    Fragkou, Vasiliki

    2010-01-01

    Diabetes is one of the leading causes of death and disability in the world. Even though insulin was discovered in 1920, an intense research on diabetes has been conducted during the last five decades and this is because of the market size. The huge demand is creating the need for the development of new approaches. This project involved the research aimed at better understanding and improvements in performance of glucose biosensors. In general, high surface area electrodes ar...

  11. Alginate cryogel based glucose biosensor

    Science.gov (United States)

    Fatoni, Amin; Windy Dwiasi, Dian; Hermawan, Dadan

    2016-02-01

    Cryogel is macroporous structure provides a large surface area for biomolecule immobilization. In this work, an alginate cryogel based biosensor was developed to detect glucose. The cryogel was prepared using alginate cross-linked by calcium chloride under sub-zero temperature. This porous structure was growth in a 100 μL micropipette tip with a glucose oxidase enzyme entrapped inside the cryogel. The glucose detection was based on the colour change of redox indicator, potassium permanganate, by the hydrogen peroxide resulted from the conversion of glucose. The result showed a porous structure of alginate cryogel with pores diameter of 20-50 μm. The developed glucose biosensor was showed a linear response in the glucose detection from 1.0 to 5.0 mM with a regression of y = 0.01x+0.02 and R2 of 0.994. Furthermore, the glucose biosensor was showed a high operational stability up to 10 times of uninterrupted glucose detections.

  12. Biosensor of endotoxin and sepsis

    Science.gov (United States)

    Shao, Yang; Wang, Xiang; Wu, Xi; Gao, Wei; He, Qing-hua; Cai, Shaoxi

    2001-09-01

    To investigate the relation between biosensor of endotoxin and endotoxin of plasma in sepsis. Method: biosensor of endotoxin was designed with technology of quartz crystal microbalance bioaffinity sensor ligand of endotoxin were immobilized by protein A conjugate. When a sample soliton of plasma containing endotoxin 0.01, 0.03, 0.06, 0.1, 0.5, 1.0Eu, treated with perchloric acid and injected into slot of quartz crystal surface respectively, the ligand was released from the surface of quartz crystal to form a more stable complex with endotoxin in solution. The endotoxin concentration corresponded to the weight change on the crystal surface, and caused change of frequency that occurred when desorbed. The result was biosensor of endotoxin might detect endotoxin of plasma in sepsis, measurements range between 0.05Eu and 0.5Eu in the stop flow mode, measurement range between 0.1Eu and 1Eu in the flow mode. The sensor of endotoxin could detect the endotoxin of plasm rapidly, and use for detection sepsis in clinically.

  13. Direct laser immobilization of photosynthetic material on screen printed electrodes for amperometric biosensor

    International Nuclear Information System (INIS)

    This letter demonstrates the direct laser printing of photosynthetic material onto low cost nonfunctionalized screen printed electrodes for the fabrication of photosynthesis-based amperometric biosensors. The high kinetic energy of the transferred material induces direct immobilization of the thylakoids onto the electrodes without the use of linkers. This type of immobilization is able to establish efficient electrochemical contact between proteins and electrode, stabilizing the photosynthetic biomolecule and transporting electrons to the solid state device with high efficiency. The functionality of the laser printed biosensors was evaluated by the detection of a common herbicide such as Linuron.

  14. Development of a criticality monitoring and alarm system

    International Nuclear Information System (INIS)

    In this work we are presenting the development of a Criticality Monitor and Alarm System (SIMAC). It monitors the burst of radiation produced during such an accident and triggers an alarm for evacuation in case the radiation exceeds a pre-established threshold. It consists of two subsystems, one for gamma rays and the other for neutrons. Each subsystem has three independent detectors modules. Each module is composed of an ion chamber plus its associated electronics, feeding a logic module that in turn would trigger the evacuation alarm. An additional feature is a PC interface for data acquisition. The radiation detectors are ion chambers working in current mode. The electronics associated to each detector can manage a wide signal range using a logarithmic converter. (author)

  15. Statistical Study of False Alarms of Geomagnetic Storms

    DEFF Research Database (Denmark)

    Leer, Kristoffer; Vennerstrøm, Susanne; Veronig, A.;

    Coronal Mass Ejections (CMEs) are known to cause geomagnetic storms on Earth. However, not all CMEs will trigger geomagnetic storms, even if they are heading towards the Earth. In this study, front side halo CMEs with speed larger than 500 km/s have been identified from the SOHO LASCO catalogue....... A subset of these halo CMEs did not cause a geomagnetic storm the following four days and have therefore been considered as false alarms. The properties of these events are investigated and discussed here. Their statistics are compared to the geo-effective CMEs. The ability to identify potential false...... alarms is considered as an important factor when forecasting geomagnetic storms. It would therefore be very helpful if there were a signature in the solar data that could indicate that a CME is a false alarm. The strength and position of associated flares have been considered as possible candidates...

  16. Off-line FIA monitoring of D-sorbitol consumption during L-sorbose production using a sorbitol biosensor.

    Science.gov (United States)

    Sefcovicová, Jana; Vikartovská, Alica; Pätoprstý, Vladimír; Magdolen, Peter; Katrlík, Jaroslav; Tkac, Jan; Gemeiner, Peter

    2009-06-30

    A ferricyanide mediated amperometric biosensor system implementing D-sorbitol dehydrogenase together with diaphorase for sensitive detection of D-sorbitol was used. The biosensor system was successfully integrated into an off-line FIA system with a throughput of detection of 10 h(-1). The device exhibited limit of detection of 20 microM with an average relative standard deviation of analysis of samples of 2.2%. The signal of the biosensor was linear up to 1.1 mM for D-sorbitol with sensitivity of (72 +/- 2) nA mM(-1), while a dynamic range was much wider up to 18 mM. The sorbitol biosensor gave reliable results even in the presence of a high molar excess of L-sorbose, a product of the biotransformation process, as judged from an excellent agreement with HPLC and GC.

  17. An Optical Biosensor for Bacillus Cereus Spore Detection

    Science.gov (United States)

    Li, Chengquan; Tom, Harry W. K.

    2005-03-01

    We demonstrate a new transduction scheme for optical biosensing. Bacillus cereus is a pathogen that may be found in food and dairy products and is able to produce toxins and cause food poisoning. It is related to Bacillus anthracis (anthrax). A CCD array covered with micro-structured glass coverslip is used to detect the optical resonant shift due to the binding of the antigen (bacillus cereus spore) to the antibody (polyclonal antibody). This novel optical biosensor scheme has the potential for detecting 10˜100 bioagents in a single device as well as the potential to test for antigens with multiple antibody tests to avoid ``false positives.''

  18. Graphene–protein field effect biosensors: glucose sensing

    Directory of Open Access Journals (Sweden)

    Sowmya Viswanathan

    2015-11-01

    Full Text Available Chronic diseases are becoming more prevalent, and the complexities of managing patients continue to escalate, since their care must be balanced between the home and clinical settings. Diabetes is the most advanced example, where self-monitoring has been shown to be necessary. Glucometers are point-of-care (POC devices that have become standard platforms at home and clinical settings. Similarly, many other POC biosensors have also been developed. Enzymes are often used in these sensors because of their specificity and the reaction products can be electrochemically transduced for the measurement. When enzymes are immobilized to an electronically active substrate, enzymatic reactions can be transduced by direct electron transport. This paper describes an approach for the development of graphene-based POC devices. This includes modifying enzymes for improved performance, developing methods to bind them to the graphene surface, incorporation of the functionalized graphene on a field-effect transistor (FET, and integration into a microfluidic device suitable for home use. This paper describes an approach for the development of a graphene-based POC biosensor platform using glucose as an example of target molecule.

  19. PROLOG language application for alarm system realization in accelerator control

    International Nuclear Information System (INIS)

    Such PROLOG features as backtracking, matching and recursive data representation are powerful tools for ALARM system realization. Although the main idea is the possibility to describe some technical system in recursive form, backtracking and matching are ideal for processing recursive data structures. This paper represents a technique which would allow PROLOG language application for ALARM system realization using an example of the KEK LINAC magnet system. The technique is based on an object-oriented internal data representation in terms of objects, properties, relations and knowledge conception. In addition, each property value is characterized by a typical 'time life'. (author)

  20. Development of conductometric biosensors based on alkaline phosphatases for the water quality control

    CERN Document Server

    Berezhetskyy, A

    2008-01-01

    Researches are focused on the elaboration of enzymatic microconductometric device for heavy metal ions detection in water solutions. The manuscript includes a general introduction, the first chapter contains bibliographic review, the second chapter described the fundamentals of conductometric transducers, the third chapter examining the possibility to create and to optimize conductometric biosensor based on bovine alkaline phosphatase for heavy metals ions detection, the fourth chapter devoted to creation and optimization of conductometric biosensor based on alkaline phosphatase active microalgae and sol gel technology, the last chapter described application of the proposed algal biosensor for measurements of heavy metal ions toxicity of waste water, general conclusions stating the progresses achieved in the field of environmental monitoring

  1. 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.

  2. ZnO-Based Amperometric Enzyme Biosensors

    Directory of Open Access Journals (Sweden)

    Helong Jiang

    2010-02-01

    Full Text Available Nanostructured ZnO with its unique properties could provide a suitable microenvironment for immobilization of enzymes while retaining their biological activity, and thus lead to an expanded use of this nanomaterial for the construction of electrochemical biosensors with enhanced analytical performance. ZnO-based enzyme electrochemical biosensors are summarized in several tables for an easy overview according to the target biosensing analyte (glucose, hydrogen peroxide, phenol and cholesterol, respectively. Moreover, recent developments in enzyme electrochemical biosensors based on ZnO nanomaterials are reviewed with an emphasis on the fabrications and features of ZnO, approaches for biosensor construction (e.g., modified electrodes and enzyme immobilization and biosensor performances.

  3. Nanomaterials based biosensors for cancer biomarker detection

    Science.gov (United States)

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

    2016-04-01

    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.

  4. Towards an integrated biosensor array for simultaneous and rapid multi-analysis of endocrine disrupting chemicals

    International Nuclear Information System (INIS)

    Highlights: ► A multitask biosensor for the detection of endocrine disrupting chemicals is proposed. ► The sensing system employ an array of biological recognition elements. ► Amperometric and optical transduction methods are provided in an integrated biosensor together with flow control systems. ► The biosensing device results in an integrated, automatic and portable system for environmental and agrifood application. - Abstract: In this paper we propose the construction and application of a portable multi-purpose biosensor array for the simultaneous detection of a wide range of endocrine disruptor chemicals (EDCs), based on the recognition operated by various enzymes and microorganisms. The developed biosensor combines both electrochemical and optical transduction systems, in order to increase the number of chemical species which can be monitored. Considering to the maximum residue level (MRL) of contaminants established by the European Commission, the biosensor system was able to detect most of the chemicals analysed with very high sensitivity. In particular, atrazine and diuron were detected with a limit of detection of 0.5 nM, with an RSD% less than 5%; paraoxon and chlorpyrifos were revealed with a detection of 5 μM and 4.5 μM, respectively, with an RSD% less than 6%; catechol and bisphenol A were identified with a limit of detection of 1 μM and 35 μM respectively, with an RSD% less than 5%.

  5. Towards an integrated biosensor array for simultaneous and rapid multi-analysis of endocrine disrupting chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Scognamiglio, Viviana, E-mail: viviana.scognamiglio@mlib.ic.cnr.it [IC-CNR Istituto di Cristallografia, AdR1 Dipartimento Agroalimentare - Via Salaria Km 29.3 00015, Rome (Italy); Pezzotti, Italo; Pezzotti, Gianni; Cano, Juan; Manfredonia, Ivano [Biosensor S.r.l. - Via degli Olmetti 44 00060 Formello, Rome (Italy); Buonasera, Katia [IC-CNR Istituto di Cristallografia, AdR1 Dipartimento Agroalimentare - Via Salaria Km 29.3 00015, Rome (Italy); Arduini, Fabiana; Moscone, Danila; Palleschi, Giuseppe [Universita di Roma Tor Vergata, Dipartimento di Scienze e Tecnologie Chimiche - Via della Ricerca Scientifica 00133, Rome (Italy); Giardi, Maria Teresa [IC-CNR Istituto di Cristallografia, AdR1 Dipartimento Agroalimentare - Via Salaria Km 29.3 00015, Rome (Italy)

    2012-11-02

    Highlights: Black-Right-Pointing-Pointer A multitask biosensor for the detection of endocrine disrupting chemicals is proposed. Black-Right-Pointing-Pointer The sensing system employ an array of biological recognition elements. Black-Right-Pointing-Pointer Amperometric and optical transduction methods are provided in an integrated biosensor together with flow control systems. Black-Right-Pointing-Pointer The biosensing device results in an integrated, automatic and portable system for environmental and agrifood application. - Abstract: In this paper we propose the construction and application of a portable multi-purpose biosensor array for the simultaneous detection of a wide range of endocrine disruptor chemicals (EDCs), based on the recognition operated by various enzymes and microorganisms. The developed biosensor combines both electrochemical and optical transduction systems, in order to increase the number of chemical species which can be monitored. Considering to the maximum residue level (MRL) of contaminants established by the European Commission, the biosensor system was able to detect most of the chemicals analysed with very high sensitivity. In particular, atrazine and diuron were detected with a limit of detection of 0.5 nM, with an RSD% less than 5%; paraoxon and chlorpyrifos were revealed with a detection of 5 {mu}M and 4.5 {mu}M, respectively, with an RSD% less than 6%; catechol and bisphenol A were identified with a limit of detection of 1 {mu}M and 35 {mu}M respectively, with an RSD% less than 5%.

  6. Alarm management in TRANSPETRO National Oil Control Center

    Energy Technology Data Exchange (ETDEWEB)

    Amado, Helio; Costa, Luciano [TRANSPETRO - PETROBRAS Transporte S.A., Rio de Janeiro, RJ (Brazil)

    2009-07-01

    For sure Alarm Management is not a new issue. EEMUA 191 has been around since 1999 and everyone has received visits from consultants in this area. Besides this regulators have requested that operators have a policy for it. However there are few papers showing actual pipeline operator experience in alarm management. In this paper we present the work developed in TRANSPETRO National Oil Control Center since 2006, where we operate 5509 km of crude oil and refined products pipelines. Since the beginning of the centralized operation in 2002, alarm management has been a concern but a systematic approach has been taken since 2006. Initially we will make a brief revision of the literature and show trends for regulations. Then we will show the tools and the approach we have taken. Finally, the further developments we see. The point that we want to discuss is that, it has been very difficult to implement the system in a linear way and we believe that companies that have huge legacy systems, the same probably will occur. Putting in simple words, our main conclusion is: Implementing an Alarm Management policy produces good results however probably sometimes is better not to follow strictly the traditional steps. (author)

  7. False Alarm Probability Estimation for Compressive Sensing Radar

    NARCIS (Netherlands)

    Anitori, L.; Otten, M.P.G.; Hoogeboom, P.

    2011-01-01

    In this paper false alarm probability (FAP) estimation of a radar using Compressive Sensing (CS) in the frequency domain is investigated. Compressive Sensing is a recently proposed technique which allows reconstruction of sparse signal from sub-Nyquist rate measurements. The estimation of the FAP is

  8. Detection of false arrhythmia alarms with emphasis on ventricular tachycardia.

    Science.gov (United States)

    Rodrigues, Rui; Couto, Paula

    2016-08-01

    Our approach to detecting false arrhythmia alarms in the intensive care unit breaks down into several tasks. It involves beat detection on different signals: electrocardiogram, photoplethysmogram and arterial blood pressure. The quality of each channel has to be estimated in order to evaluate the reliability of obtained beat detections. The information about the heart rate from the different channels must be integrated in order to find a final conclusion. Some alarm types require particular detectors as is the case of ventricular fibrillation. To identify false ventricular tachycardia alarms we needed to classify heart beats as normal/ventricular. For that purpose we introduce a new feature, QRS polarity type. This feature was important in order to reduce misclassification of ventricular beats: there was an improvement in the ventricular tachycardia alarm true positive rate from 69% to 81%. However, the true negative rate was reduced from 95% to 69% and our global challenge score (real-time event) dropped from 79.02 to 74.28. Our challenge algorithm achieved the third best score in the 2015 PhysioNet/CinC challenge event 1 (real time). PMID:27454934

  9. 29 CFR 1910.165 - Employee alarm systems.

    Science.gov (United States)

    2010-07-01

    ... Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH STANDARDS Fire Protection Other Fire Protection Systems § 1910.165 Employee... communication system also serves as the employee alarm system, all emergency messages shall have priority...

  10. 46 CFR 120.550 - General alarm systems.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false General alarm systems. 120.550 Section 120.550 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING MORE THAN 150 PASSENGERS OR WITH OVERNIGHT ACCOMMODATIONS FOR MORE THAN 49 PASSENGERS ELECTRICAL INSTALLATION...

  11. 46 CFR 162.050-35 - Bilge alarm: Approval tests.

    Science.gov (United States)

    2010-10-01

    ... concentration of iron oxide. Any change in the bilge alarm reading during the 5 minutes is recorded. (3) Repeat steps in paragraphs (c)(1) and (2) of this section using iron oxide concentrations of 50 ppm and 100 ppm... performed using test fluids described in § 162.050-20. (3) The oil content of each sample must be...

  12. SGLT-2 inhibition and glucagon: Cause for alarm?

    Science.gov (United States)

    Kibbey, Richard G

    2015-07-01

    Recent studies raised the alarm that the inhibition of sodium-coupled glucose transporter type-2 in humans increases endogenous glucose production rates by an unclear mechanism. Surprisingly, a potential explanation may be linked directly to the alpha-cell. Is this a mechanistic spoiler or an added benefit? PMID:26059706

  13. Carbon nanotubes field effect transistors biosensors

    Directory of Open Access Journals (Sweden)

    M.P. Marco

    2012-03-01

    Full Text Available Carbon nanotube transistor arrays (CNTFETs wereused as biosensors to detect DNA hybridization andto recognize two anabolic steroids, stanozolol (Stzand methylboldenone (MB. Single strand DNA andantibodies specific for STz and MB were immobilizedon the carbon nanotubes (CNTs in situ in the deviceusing two different approaches: direct noncovalentbonding of antibodies to the devices and covalentlytrough a polymer previously attached to theCNTFETs. A new approach to ensure specificadsorption of the biomolecules to the nanotubeswas developed. The polymer poly(methylmethacrylate0.8-co-poly (ethyleneglycolmethacrylate0.8-co-N-succinimidyl methacrylate0.1was synthesized and bonded noncovalently to thenanotube. Aminated single-strand DNA or antibodiesspecific for Stz and MB were then attached covalentlyto the polymer. Statistically significant changes wereobserved in key transistor parameters for both DNAhybridization and steroids recognition. Regardingthe detection mechanism, in addition to chargetransfer, Schottky barrier, SB, modification, andscattering potential reported by other authors, anelectron/hole trapping mechanism leading tohysteresis modification has been determined. Thepresence of polymer seems to hinder the modulationof the electrode-CNT contact.

  14. Biosensors for the Detection of Food Pathogens

    Directory of Open Access Journals (Sweden)

    Palmiro Poltronieri

    2014-09-01

    Full Text Available Food pathogens frequently cause foodborne diseases. There is a need to rapidly identify the source of the bacteria in order to contain their spread and epidemics. A pre-enrichment culture or a direct culture on agar plate are standard microbiological methods. In this review, we present an update on alternative molecular methods to nucleic acid-based detection for species identification. Biosensor-based methods rely on the recognition of antigen targets or receptors by antibodies, aptamers or high-affinity ligands. The captured antigens may be then directly or indirectly detected through an antibody or high-affinity and high-specificity recognition molecule. Various different detection methods are discussed, from label-free sensors and immunosensors to fluorescence-based ones. Each method shows advantages and disadvantages in terms of equipment, sensitivity, simplicity and cost-effectiveness. Finally, lab-on-a-chip (LOC devices are introduced briefly, with the potential to be fast, sensitive and useful for on-site bacteria detection in food processing laboratories to check potential contamination by sample monitoring combined with a rapid pre-enrichment step.

  15. Feasibility Studies on Si-Based Biosensors

    Directory of Open Access Journals (Sweden)

    Marcella Renis

    2009-05-01

    Full Text Available The aim of this paperis to summarize the efforts carried out so far in the fabrication of Si-based biosensors by a team of researchers in Catania, Italy. This work was born as a collaboration between the Catania section of the Microelectronic and Microsystem Institute (IMM of the CNR, the Surfaces and Interfaces laboratory (SUPERLAB of the Consorzio Catania Ricerche and two departments at the University of Catania: the Biomedical Science and the Biological Chemistry and Molecular Biology Departments. The first goal of our study was the definition and optimization of an immobilization protocol capable of bonding the biological sensing element on a Si-based surface via covalent chemical bonds. We chose SiO2 as the anchoring surface due to its biocompatibility and extensive presence in microelectronic devices. The immobilization protocol was tested and optimized, introducing a new step, oxide activation, using techniques compatible with microelectronic processing. The importance of the added step is described by the experimental results. We also tested different biological molecule concentrations in the immobilization solutions and the effects on the immobilized layer. Finally a MOS-like structure was designed and fabricated to test an electrical transduction mechanism. The results obtained so far and the possible evolution of the research field are described in this review paper.

  16. TIGER: the universal biosensor

    Science.gov (United States)

    Hofstadler, Steven A.; Sampath, Rangarajan; Blyn, Lawrence B.; Eshoo, Mark W.; Hall, Thomas A.; Jiang, Yun; Drader, Jared J.; Hannis, James C.; Sannes-Lowery, Kristin A.; Cummins, Lendell L.; Libby, Brian; Walcott, Demetrius J.; Schink, Amy; Massire, Christian; Ranken, Raymond; Gutierrez, Jose; Manalili, Sheri; Ivy, Cristina; Melton, Rachael; Levene, Harold; Barrett-Wilt, Greg; Li, Feng; Zapp, Vanessa; White, Neill; Samant, Vivek; McNeil, John A.; Knize, Duane; Robbins, David; Rudnick, Karl; Desai, Anjali; Moradi, Emily; Ecker, David J.

    2005-03-01

    In this work, we describe a strategy for the detection and characterization of microorganisms associated with a potential biological warfare attack or a natural outbreak of an emerging infectious disease. This approach, termed TIGER (Triangulation Identification for the Genetic Evaluation of Risks), relies on mass spectrometry-derived base composition signatures obtained from PCR amplification of broadly conserved regions of the microbial genome(s) in a sample. The sample can be derived from air filtration devices, clinical samples, or other sources. Core to this approach are "intelligent PCR primers" that target broadly conserved regions of microbial genomes that flank variable regions. This approach requires that high-performance mass measurements be made on PCR products in the 80-140 bp size range in a high-throughput, robust modality. As will be demonstrated, the concept is equally applicable to bacteria and viruses and could be further applied to fungi and protozoa. In addition to describing the fundamental strategy of this approach, several specific examples of TIGER are presented that illustrate the impact this approach could have on the way biological weapons attacks are detected and the way that the etiologies of infectious diseases are determined. The first example illustrates how any bacterial species might be identified, using Bacillus anthracis as the test agent. The second example demonstrates how DNA-genome viruses are identified using five members of Poxviridae family, whose members includes Variola virus, the agent responsible for smallpox. The third example demonstrates how RNA-genome viruses are identified using the Alphaviruses (VEE, WEE, and EEE) as representative examples. These examples illustrate how the TIGER technology can be applied to create a universal identification strategy for all pathogens, including those that infect humans, livestock, and plants.

  17. Glucose biosensor enhanced by nanoparticles

    Institute of Scientific and Technical Information of China (English)

    唐芳琼; 孟宪伟; 陈东; 冉均国; 郑昌琼

    2000-01-01

    Glucose biosensors have been formed with glucose oxidase (GOD) immobilized in composite immobilization membrane matrix, which is composed of hydrophobic gold, or hydro-philic gold, or hydrophobic silica nanoparticles, or the combination of gold and silica nanoparticles, and polyvinyl butyral (PVB) by a sol-gel method. The experiments show that nanoparticles can significantly enhance the catalytic activity of the immobilization enzyme. The current response can be increased from tens of nanoamperometer (nA) to thousands of nanoamperometer to the same glucose concentration, and the electrodes respond very quickly, to about 1 min. The function of nanoparticles effect on immobilization enzyme has been discussed.

  18. Glucose biosensor enhanced by nanoparticles

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Glucose biosensors have been formed with glucose oxidase (GOD) immobilized in composite immobilization membrane matrix, which is composed of hydrophobic gold, or hydrophilic gold, or hydrophobic silica nanoparticles, or the combination of gold and silica nanoparticles, and polyvinyl butyral (PVB) by a sol-gel method. The experiments show that nanoparticles can significantly enhance the catalytic activity of the immobilization enzyme. The current response can be increased from tens of nanoamperometer (nA) to thousands of nanoamperometer to the same glucose concentration, and the electrodes respond very quickly, to about 1 min. The function of nanoparticles effect on immobilization enzyme has been discussed.

  19. Retrofitting alarm prioritization at Bruce A: strategy development and implementation experience

    International Nuclear Information System (INIS)

    A prioritization strategy for computer-displayed control room alarms has been developed for Bruce A to better assist operations staff in visually identifying key alarms and judging the relative importance of alarms. The strategy consists of assigning each alarm indicative of a problem to be addressed to one of five priority categories. Each alarm is assigned to an alarm category based on an off-line analysis of the consequence and response characteristics applicable to the alarm for three plant operating contexts. The colour of the alarm message is used to convey the priority category of each alarm in computer-based alarm displays. In addition, alarms indicative of non-problematic changes in the state of plant equipment and processes are given a separate colour assignment to visually differentiate them from alarms indicative of problems. This paper outlines the user-based approach employed in the prioritization strategy development, describes the key features of the prioritization strategy adopted, and discusses the initial experience in systematically determining the priority assignments for all 6000 computer-based alarms associated with each generating unit. (author)

  20. Escherichia coli bacteria detection by using graphene-based biosensor.

    Science.gov (United States)

    Akbari, Elnaz; Buntat, Zolkafle; Afroozeh, Abdolkarim; Zeinalinezhad, Alireza; Nikoukar, Ali

    2015-10-01

    Graphene is an allotrope of carbon with two-dimensional (2D) monolayer honeycombs. A larger detection area and higher sensitivity can be provided by graphene-based nanosenor because of its 2D structure. In addition, owing to its special characteristics, including electrical, optical and physical properties, graphene is known as a more suitable candidate compared to other materials used in the sensor application. A novel model employing a field-effect transistor structure using graphene is proposed and the current-voltage (I-V) characteristics of graphene are employed to model the sensing mechanism. This biosensor can detect Escherichia coli (E. coli) bacteria, providing high levels of sensitivity. It is observed that the graphene device experiences a drastic increase in conductance when exposed to E. coli bacteria at 0-10(5) cfu/ml concentration. The simple, fast response and high sensitivity of this nanoelectronic biosensor make it a suitable device in screening and functional studies of antibacterial drugs and an ideal high-throughput platform which can detect any pathogenic bacteria. Artificial neural network and support vector regression algorithms have also been used to provide other models for the I-V characteristic. A satisfactory agreement has been presented by comparison between the proposed models with the experimental data. PMID:26435280

  1. Learning from adverse incidents involving medical devices.

    Science.gov (United States)

    Amoore, John; Ingram, Paula

    While an adverse event involving a medical device is often ascribed to either user error or device failure, the causes are typically multifactorial. A number of incidents involving medical devices are explored using this approach to investigate the various causes of the incident and the protective barriers that minimised or prevented adverse consequences. User factors, including mistakes, omissions and lack of training, conspired with background factors--device controls and device design, storage conditions, hidden device damage and physical layout of equipment when in use--to cause the adverse events. Protective barriers that prevented or minimised the consequences included staff vigilance, operating procedures and alarms. PMID:12715578

  2. A novel biosensor for p-nitrophenol based on an aerobic anode microbial fuel cell.

    Science.gov (United States)

    Chen, Zhengjun; Niu, Yongyan; Zhao, Shuai; Khan, Aman; Ling, Zhenmin; Chen, Yong; Liu, Pu; Li, Xiangkai

    2016-11-15

    P-nitrophenol is one of the most common contaminants in chemical industrial wastewater, and in situ real-time monitoring of PNP cannot be achieved by conventional analytical techniques. Here, a two-chamber microbial fuel cell with an aerobic anode chamber was tested as a biosensor for in situ real-time monitoring of PNP. Pseudomonas monteilii LZU-3, which was used as the biological recognition element, can form a biofilm on the anode electrode using PNP as a sole substrate. The optimal operation parameters of the biosensor were as follows: external resistance 1000Ω, pH 7.8, temperature 30°C, and maximum PNP concentration 50mgL(-1). Under these conditions, the maximum voltages showed a linear relationship with PNP concentrations ranging from 15±5 to 44±4.5mgL(-1). Furthermore, we developed a novel portable device for in situ real-time monitoring of PNP. When the device was applied to measure PNP in wastewater containing various additional aromatic compounds and metal ions, the performance of the biosensor was not affected and the correlation between the maximum voltages and the PNP concentrations ranging from 9±4mgL(-1) to 36 ± 5mgL(-1) was conserved. The results demonstrated that the MFC biosensor provides a rapid and cost-efficient analytical method for real-time monitoring of toxic and recalcitrant pollutants in environmental samples. PMID:27295573

  3. Two-dimensional layered MoS₂ biosensors enable highly sensitive detection of biomolecules.

    Science.gov (United States)

    Lee, Joonhyung; Dak, Piyush; Lee, Yeonsung; Park, Heekyeong; Choi, Woong; Alam, Muhammad A; Kim, Sunkook

    2014-01-01

    We present a MoS2 biosensor to electrically detect prostate specific antigen (PSA) in a highly sensitive and label-free manner. Unlike previous MoS2-FET-based biosensors, the device configuration of our biosensors does not require a dielectric layer such as HfO2 due to the hydrophobicity of MoS2. Such an oxide-free operation improves sensitivity and simplifies sensor design. For a quantitative and selective detection of PSA antigen, anti-PSA antibody was immobilized on the sensor surface. Then, introduction of PSA antigen, into the anti-PSA immobilized sensor surface resulted in a lable-free immunoassary format. Measured off-state current of the device showed a significant decrease as the applied PSA concentration was increased. The minimum detectable concentration of PSA is 1 pg/mL, which is several orders of magnitude below the clinical cut-off level of ~4 ng/mL. In addition, we also provide a systematic theoretical analysis of the sensor platform - including the charge state of protein at the specific pH level, and self-consistent channel transport. Taken together, the experimental demonstration and the theoretical framework provide a comprehensive description of the performance potential of dielectric-free MoS2-based biosensor technology.

  4. Referral to the accident and emergency department following the use of community alarms

    OpenAIRE

    Youssef, G.; Underhill, T; Tovey, C

    2000-01-01

    Objectives—To assess the degree of appropriate referral to the accident and emergency (A&E) department following the use of a community alarm where a mobile warden works in conjunction with the community alarm control centre.

  5. 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...

  6. Modeling amperometric biosensors based on allosteric enzymes

    Directory of Open Access Journals (Sweden)

    Liutauras Ričkus

    2013-09-01

    Full Text Available Computational modeling of a biosensor with allosteric enzyme layer was investigated in this study. The operation of the biosensor is modeled using non-stationary reaction-diffusion equations. The model involves three regions: the allosteric enzyme layer where the allosteric enzyme reactions as well as then mass transport by diffusion take place, the diffusion region where the mass transport by diffusion and non-enzymatic reactions take place and the convective region in which the analyte concentration is maintained constant. The biosensor response on dependency substrate concentration, cooperativity coefficient and the diffusion layer thickness on the same parameters have been studied.

  7. Silicon photonic crystal resonators for label free biosensor

    Science.gov (United States)

    Sana, Amrita Kumar; Honzawa, Keita; Amemiya, Yoshiteru; Yokoyama, Shin

    2016-04-01

    We report the fabrication and characterization of a two-dimensional (2D) silicon photonic crystal biosensor consisting of waveguides and cavity-type and defect-type resonators for enhancing the interactions between light and biomaterials. Sensitivity was measured using sucrose solution and the sensor showed the highest sensitivity [1570 nm/RIU (refractive index unit)] ever reported. We also investigated cavity size effects on resonance wavelength shift, and we observed that a large cavity exhibits a greater resonance wavelength shift. The fabricated sensor has shown a high Q of ∼105 in water and a device figure of merit of 1.2 × 105, which represent the improvements of the device performance over other photonic-crystal-based sensors.

  8. Plasmon based biosensor for distinguishing different peptides mutation states

    KAUST Repository

    Das, Gobind

    2013-05-08

    Periodic and reproducible gold nanocuboids with various matrix dimensions and with different inter-particle gaps were fabricated by means of top-down technique. Rhodamine 6G was used as a probe molecule to optimize the design and the fabrication of the cuboid nanostructures. The electric field distribution for the nanocuboids with varying matrix dimensions/inter-particle gap was also investigated. These SERS devices were employed as biosensors through the investigation of both myoglobin and wild/mutated peptides. The results demonstrate the probing and the screening of wild/mutated BRCA1 peptides, thus opening a path for the fabrication of simple and cheap SERS device capable of early detection of several diseases.

  9. Efficiency of Fire Protection Devices in Buildings: Evidence from Response data

    OpenAIRE

    Jaldell, Henrik

    2012-01-01

    This study investigates the effectiveness of fire protection devices, such as smoke detectors, portable fire extinguishers, automatic fire alarms, sprinklers etc., in different types of buildings in Sweden. It contributes two aspects not taken into account in other studies of the effect of fire protection devices. First, response time is taken into account and, second, multiple fire protection devices are considered together. The results show that, for most types of buildings, automatic alarm...

  10. A Fiber-Optical Intrusion Alarm System Based on Quasi-Distributed Fiber Bragg Grating Sensors

    Institute of Scientific and Technical Information of China (English)

    Qi Jiang; Yun-Jiang Rao; De-Hong Zeng

    2008-01-01

    A fiber-optical intrusion alarm system based on quasi-distributed fiber Bragg grating (FBG) sensors is demonstrated in this paper. The algorithms of empirical mode decomposition (EMD) and wavelet packet characteristic entropy are adopted to determine the intrusion location. The intrusion alarm software based on the Labview is developed, and it is also proved by the experiments. The results show that such a fiber-optical intrusion alarm system can offer the automatic intrusion alarm in real-time.

  11. Preventing Charlie's in a chocolate factory: a human factors perspective of alarm handling in confectionary manufacture

    OpenAIRE

    Stanton, Neville A.

    1991-01-01

    The article analyses the results of a survey of a small population of Control Desk Engineers at a UK manufacturing plant. Specific objectives were to elicit the engineers' definition of the term `alarm', to examine their alarm handling activities, and to get information on problems with the alarm system

  12. 46 CFR 153.438 - Cargo pressure or temperature alarms required.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Cargo pressure or temperature alarms required. 153.438... Equipment Cargo Temperature Control Systems § 153.438 Cargo pressure or temperature alarms required. (a... vapor pressure described in § 153.371(b); or (2) An alarm that operates when the cargo's...

  13. Chimpanzee alarm call production meets key criteria for intentionality.

    Science.gov (United States)

    Schel, Anne Marijke; Townsend, Simon W; Machanda, Zarin; Zuberbühler, Klaus; Slocombe, Katie E

    2013-01-01

    Determining the intentionality of primate communication is critical to understanding the evolution of human language. Although intentional signalling has been claimed for some great ape gestural signals, comparable evidence is currently lacking for their vocal signals. We presented wild chimpanzees with a python model and found that two of three alarm call types exhibited characteristics previously used to argue for intentionality in gestural communication. These alarm calls were: (i) socially directed and given to the arrival of friends, (ii) associated with visual monitoring of the audience and gaze alternations, and (iii) goal directed, as calling only stopped when recipients were safe from the predator. Our results demonstrate that certain vocalisations of our closest living relatives qualify as intentional signals, in a directly comparable way to many great ape gestures. We conclude that our results undermine a central argument of gestural theories of language evolution and instead support a multimodal origin of human language. PMID:24146908

  14. Chimpanzee alarm call production meets key criteria for intentionality.

    Directory of Open Access Journals (Sweden)

    Anne Marijke Schel

    Full Text Available Determining the intentionality of primate communication is critical to understanding the evolution of human language. Although intentional signalling has been claimed for some great ape gestural signals, comparable evidence is currently lacking for their vocal signals. We presented wild chimpanzees with a python model and found that two of three alarm call types exhibited characteristics previously used to argue for intentionality in gestural communication. These alarm calls were: (i socially directed and given to the arrival of friends, (ii associated with visual monitoring of the audience and gaze alternations, and (iii goal directed, as calling only stopped when recipients were safe from the predator. Our results demonstrate that certain vocalisations of our closest living relatives qualify as intentional signals, in a directly comparable way to many great ape gestures. We conclude that our results undermine a central argument of gestural theories of language evolution and instead support a multimodal origin of human language.

  15. Fluorescence-based biosensor for monitoring of environmental pollutants: From concept to field application.

    Science.gov (United States)

    Bidmanova, Sarka; Kotlanova, Marketa; Rataj, Tomas; Damborsky, Jiri; Trtilek, Martin; Prokop, Zbynek

    2016-10-15

    An advanced optical biosensor was developed based on the enzymatic reaction with halogenated aliphatic hydrocarbons that is accompanied by the fluorescence change of pH indicator. The device is applicable for the detection of halogenated contaminants in water samples with pH ranging from 4 to 10 and temperature ranging from 5 to 60°C. Main advantages of the developed biosensor are small size (60×30×190mm(3)) and portability, which together with short measurement time of 1min belong to crucial attributes of analytical technique useful for routine environmental monitoring. The biosensor was successfully applied for the detection of several important halogenated pollutants under laboratory conditions, e.g., 1,2-dichloroethane, 1,2,3-trichloropropane and γ-hexachlorocyclohexane, with the limits of detection of 2.7, 1.4 and 12.1mgL(-1), respectively. The continuous monitoring was demonstrated by repetitive injection of halogenated compound into measurement solution. Consequently, field trials under environmental settings were performed. The presence of 1,2-dichloroethane (10mgL(-1)) was proved unambiguously on one of three potentially contaminated sites in Czech Republic, and the same contaminant was monitored on contaminated locality in Serbia. Equipped by Global Positioning System, the biosensor was used for creation of a precise map of contamination. Concentrations determined by biosensor and by gas chromatograph coupled with mass spectrometer exhibited the correlation coefficient of 0.92, providing a good confidence for the routine use of the biosensor system in both field screening and monitoring. PMID:26725215

  16. Portable source identification device

    Science.gov (United States)

    Andersen, Eric S.; Samuel, Todd J.; Gervais, Kevin L.

    2005-05-01

    U.S. Customs and Border Protection (CBP) is the primary enforcement agency protecting the nation"s ports of entry. CBP is enhancing its capability to interdict the illicit import of nuclear and radiological materials and devices that may be used by terrorists. Pacific Northwest National Laboratory (PNNL) is providing scientific and technical support to CBP in their goal to enable rapid deployment of nuclear and radiation detection systems at U. S. ports of entry to monitor 100% of the incoming international traffic and cargo while not adversely impacting the operations or throughput of the ports. As the deployment of radiation detection systems proceeds, there is a need to adapt the baseline radiation portal monitor (RPM) system technology to operations at these diverse ports of entry. When screening produces an alarm in the primary inspection RPM, the alarming vehicle is removed from the flow of commerce and the alarm is typically confirmed in a secondary inspection RPM. The portable source identification device (PSID) is a radiation sensor panel (RSP), based on thallium-doped sodium iodide (NaI(Tl)) scintillation detector and gamma spectroscopic analysis hardware and software, mounted on a scissor lift on a small truck. The lift supports a box containing a commercial off-the-shelf (COTS) sodium iodide detector that provides real-time isotopic identification, including neutron detectors to interdict Weapons of Mass Destruction (WMD) and radiation dispersion devices (RDD). The scissor lift will lower the detectors to within a foot off the ground and raise them to approximately 24 feet (7.3 m) in the air, allowing a wide vertical scanning range.

  17. Chimpanzee alarm call production meets key criteria for intentionality

    OpenAIRE

    Anne Marijke Schel; Simon W Townsend; Zarin Machanda; Klaus Zuberbühler; Slocombe, Katie E.

    2013-01-01

    BBSRC-funded, but difficult to identify the specific grant. Determining the intentionality of primate communication is critical to understanding the evolution of human language. Although intentional signalling has been claimed for some great ape gestural signals, comparable evidence is currently lacking for their vocal signals. We presented wild chimpanzees with a python model and found that two of three alarm call types exhibited characteristics previously used to argue for intentionality...

  18. Design of Textile Moisture Sensor for Enuresis Alarm System

    OpenAIRE

    Kašurina, I; Vališevskis, A; Briedis, U; Viļumsone, A

    2012-01-01

    To improve the comfort properties of nocturnal enuresis alarm system, a modular humidity sensor should be replaced with a textile sensor. During research, two-electrode textile moisture sensor has been developed to study its electrical properties. To define the optimal type of a sensor, several sensor samples have been made using different configurations of sensor electrodes, yarn type and distance between parallel seams. Samples of sensor have been tested in terms of sig...

  19. Alarm handling for health monitoring: operator strategies used in an electrical control room of a rail network

    OpenAIRE

    Dadashi, Nastaran; Wilson, John R; Golightly, David; Sharples, Sarah

    2016-01-01

    Alarm management is a key component of the successful operation of a prognostic or health-monitoring technology. Although alarms can alert the operator to critical information, false alarms and alarm flooding can cause major difficulties for successfully diagnosing and acting upon infrastructure faults. Human factors approaches seek to design more-effective alarm systems through a deep understanding of the contextual factors that influence alarm response, including strategies and heuristics u...

  20. Photonic crystal biosensor in spatial fourier domain

    OpenAIRE

    Hallynck, Elewout; Bienstman, Peter

    2011-01-01

    We propose a photonic crystal biosensor, operating at a single wavelength, based on analysis of resonant guided modes in the spatial Fourier domain. Sensitivities of 65 degrees per RIU and more have been simulated.

  1. Recent Advances in Nanotechnology Applied to Biosensors

    Directory of Open Access Journals (Sweden)

    Daxiang Cui

    2009-02-01

    Full Text Available In recent years there has been great progress the application of nanomaterials in biosensors. The importance of these to the fundamental development of biosensors has been recognized. In particular, nanomaterials such as gold nanoparticles, carbon nanotubes, magnetic nanoparticles and quantum dots have been being actively investigated for their applications in biosensors, which have become a new interdisciplinary frontier between biological detection and material science. Here we review some of the main advances in this field over the past few years, explore the application prospects, and discuss the issues, approaches, and challenges, with the aim of stimulating a broader interest in developing nanomaterial-based biosensors and improving their applications in disease diagnosis and food safety examination.

  2. Microalgae dual-head biosensors for selective detection of herbicides with fiber-optic luminescent O2 transduction.

    Science.gov (United States)

    Haigh-Flórez, David; de la Hera, Cristina; Costas, Eduardo; Orellana, Guillermo

    2014-04-15

    The microalgal species Dictyosphaerium chlorelloides (D. c.) was immobilized into porous silicone films and their photosynthetic activity was monitored with an integrated robust luminescent O2 sensor. The biosensor specificity towards a particular pesticide has been achieved by manufacturing a fiber-optic dual-head device containing both analyte-sensitive and analyte-resistant D. c. strains. The latter are not genetically modified microalgae, but a product of modified Luria-Delbrück fluctuation analysis followed by ratchet selection cycles. In this way the target herbicide decreases the O2 production of the analyte-sensitive immobilized strain without affecting the analyte-resistant population response; any other pollutant will lower the O2 production of both strains. The effect of the sample flow-rate, exposure time to the herbicide, biomass loading, biosensor film thickness, intensity of the actinic light, illumination cycle, and temperature on the biosensor response has been evaluated using waterborne simazine as test bench. The biosensing device is able to provide in situ measurements of the herbicide concentration every 180 min. The biosensor limit of detection for this herbicide was 12 μg L(-1), with a working range of 50-800 μg L(-1). The biosensor specificity to simazine has been assessed by comparing its response to that of isoproturon. PMID:24316451

  3. On preserving robustness-false alarm tradeoff in media hashing

    Science.gov (United States)

    Roy, S.; Zhu, X.; Yuan, J.; Chang, E.-C.

    2007-01-01

    This paper discusses one of the important issues in generating a robust media hash. Robustness of a media hashing algorithm is primarily determined by three factors, (1) robustness-false alarm tradeoff achieved by the chosen feature representation, (2) accuracy of the bit extraction step and (3) the distance measure used to measure similarity (dissimilarity) between two hashes. The robustness-false alarm tradeoff in feature space is measured by a similarity (dissimilarity) measure and it defines a limit on the performance of the hashing algorithm. The distance measure used to compute the distance between the hashes determines how far this tradeoff in the feature space is preserved through the bit extraction step. Hence the bit extraction step is crucial, in defining the robustness of a hashing algorithm. Although this is recognized as an important requirement by all, to our knowledge there is no work in the existing literature that elucidates the effcacy of their algorithm based on their effectiveness in improving this tradeoff compared to other methods. This paper specifically demonstrates the kind of robustness false alarm tradeoff achieved by existing methods and proposes a method for hashing that clearly improves this tradeoff.

  4. Enzyme conductometric biosensor for maltose determination

    OpenAIRE

    Dzyadevych S. V.; Soldatkin O. O.; Saiapina O. Y.; Pyeshkova V. M.

    2009-01-01

    Aim. To develop enzyme conductometric biosensor for maltose determination. Methods. A conductometric transducer consisting of two gold pairs of electrodes was applied. Three-enzyme membrane (glucose oxidase, mutarotase, -glucosidase) immobilized on the surface of the conductometric transducer was used as a bioselective element. Results. A linear range of maltose conductometric biosensor was from 0,002 mM to 1 mM for glucose and maltose detection. The time of maltose analysis in solution was 1...

  5. Amperometric biosensors based on conducting nanotubes

    OpenAIRE

    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 the factors influencing the in vivo behaviour of implanted biosensors. The first part of this thesis describes the construction of an amperometric glucose sensor based on the enzyme glucose oxidase...

  6. ZnO-Based Amperometric Enzyme Biosensors

    OpenAIRE

    Helong Jiang; Baoping Wang; Xiaobing Zhang; Zhiwei Zhao; Wei Lei

    2010-01-01

    Nanostructured ZnO with its unique properties could provide a suitable microenvironment for immobilization of enzymes while retaining their biological activity, and thus lead to an expanded use of this nanomaterial for the construction of electrochemical biosensors with enhanced analytical performance. ZnO-based enzyme electrochemical biosensors are summarized in several tables for an easy overview according to the target biosensing analyte (glucose, hydrogen peroxide, phenol and cholesterol)...

  7. Intelligent Communication Module for Wireless Biosensor Networks

    OpenAIRE

    Naik, R.; Singh, J.; Le, H. P.

    2010-01-01

    This chapter presented a new paradigm of biosensors which have processing capability with an intelligent and adaptive wireless communication module. The adaptive communication module efficiently reconfigures its hardware components according to the changes in operating environment in order to reduce system power consumption and optimally utilise resources. The chapter presented several significant applications of wireless biosensor networks which hold enormous potential to benefit the communi...

  8. Gold coated ZnO nanorod biosensor for glucose detection

    Science.gov (United States)

    Bhattacharya, Anuradha; Jain, Chhavi; Rao, V. Padmanapan; Banerjee, S.

    2012-06-01

    Gold coated ZnO nanorod based biosensor has been fabricated for its glucose detecting abilities and compared with that of ZnO nanorod based biosensor. SEM images of electrochemically grown ZnO nanorods show hexagonally grown ZnO nanorods on an ITO substrate. Electrochemical analysis show that gold coated ZnO based biosensors have higher sensitivity, lower limit of detection and a wider linear range for glucose detection. The results demonstrate that gold coated ZnO nanorod based biosensors are a promising material for biosensor applications over single component ZnO nanorod based biosensor.

  9. Integration of Fractal Biosensor in a Digital Microfluidic Platform

    KAUST Repository

    Mashraei, Yousof

    2016-06-08

    The digital microfluidic (DMF) platform introduces many applications in biomedical assays. If it is to be commercially available to the public, it needs to have the essential features of smart sensing and a compact size. In this work, we report on a fractal electrode biosensor that is used for both droplet actuation and sensing C-reactive protein (CRP) concentration levels to assess cardiac disease risk. Our proposed electrode is the first two-terminal electrode design to be integrated into DMF platforms. A simulation of the electrical field distribution shows reduced peak intensities and uniform distribution of the field. When compared to a V-notch square electrode, the fractal electrode shows a superior performance in both aspects, i.e. field uniformity and intensity. These improvements are translated into a successful and responsive actuation of a water droplet with 100V. Likewise, the effective dielectric strength is improved by a 33% increase in the fractal electrode breakdown voltage. Additionally, the capability of the fractal electrode to work as a capacitive biosensor is evaluated with CRP quantification test. Selected fractal electrodes undergo a surface treatment to immobilize anti-CRP antibodies on their surface. The measurement shows a response to the added CRP in capacitance within three minutes. When the untreated electrodes were used for quantification, there was no significant change in capacitance, and this suggested that immobilization was necessary. The electrodes configuration in the fabricated DMF platform allows the fractal electrodes to be selectively used as biosensors, which means the device could be integrated into point-of-care applications.

  10. Increasing smoke alarm operability through theory-based health education: a randomised trial

    Science.gov (United States)

    Miller, Ted R; Bergen, Gwen; Ballesteros, Michael F; Bhattacharya, Soma; Gielen, Andrea Carlson; Sheppard, Monique S

    2015-01-01

    Background Although working smoke alarms halve deaths in residential fires, many households do not keep alarms operational. We tested whether theory-based education increases alarm operability. Methods Randomised multiarm trial, with a single arm randomly selected for use each day, in low-income neighbourhoods in Maryland, USA. Intervention arms: (1) Full Education combining a health belief module with a social-cognitive theory module that provided hands-on practice installing alarm batteries and using the alarm’s hush button; (2) Hands-on Practice social-cognitive module supplemented by typical fire department education; (3) Current Norm receiving typical fire department education only. Four hundred and thirty-six homes recruited through churches or by knocking on doors in 2005–2008. Followup visits checked alarm operability in 370 homes (85%) 1–3.5 years after installation. Main outcome measures: number of homes with working alarms defined as alarms with working batteries or hard-wired and number of working alarms per home. Regressions controlled for alarm status preintervention; demographics and beliefs about fire risks and alarm effectiveness. Results Homes in the Full Education and Practice arms were more likely to have a functioning smoke alarm at follow-up (OR=2.77, 95% CI 1.09 to 7.03) and had an average of 0.32 more working alarms per home (95% CI 0.09 to 0.56). Working alarms per home rose 16%. Full Education and Practice had similar effectiveness (p=0.97 on both outcome measures). Conclusions Without exceeding typical fire department installation time, installers can achieve greater smoke alarm operability. Hands-on practice is key. Two years after installation, for every three homes that received hands-on practice, one had an additional working alarm. Trial registration number http://www.clinicaltrials.gov number NCT00139126. PMID:25165090

  11. Advanced Monitoring Is Associated with Fewer Alarm Events During Planned Moderate Procedure-Related Sedation: A 2-Part Pilot Trial

    Science.gov (United States)

    Lenart, John; Malkin, Mathew; Meineke, Minhthy N.; Qoshlli, Silvana; Neumann, Monica; Jacobson, J. Paul; Kruger, Alison; Ching, Jeffrey; Hassanian, Mohammad; Um, Michael

    2016-01-01

    BACKGROUND: Diagnostic and interventional procedures are often facilitated by moderate procedure-related sedation. Many studies support the overall safety of this sedation; however, adverse cardiovascular and respiratory events are reported in up to 70% of these procedures, more frequently in very young, very old, or sicker patients. Monitoring with pulse oximetry may underreport hypoventilation during sedation, particularly if supplemental oxygen is provided. Capnometry may result in false alarms during sedation when patients mouth breathe or displace sampling devices. Advanced monitor use during sedation may allow event detection before complications develop. This 2-part pilot study used advanced monitors during planned moderate sedation to (1) determine incidences of desaturation, low respiratory rate, and deeper than intended sedation alarm events; and (2) determine whether advanced monitor use is associated with fewer alarm events. METHODS: Adult patients undergoing scheduled gastroenterology or interventional radiology procedures with planned moderate sedation given by dedicated sedation nurses under the direction of procedural physicians (procedural sedation team) were monitored per standard protocols (electrocardiography blood pressure, pulse oximetry, and capnometry) and advanced monitors (acoustic respiratory monitoring and processed electroencephalograpy). Data were collected to computers for analysis. Advanced monitor parameters were not visible to teams in part 1 (standard) but were visible to teams in part 2 (advanced). Alarm events were defined as desaturation—Spo2 ≤92%; respiratory depression, acoustic respiratory rate ≤8 breaths per minute, and deeper than intended sedation, indicated by processed electroencephalograpy. The number of alarm events was compared. RESULTS: Of 100 patients enrolled, 10 were excluded for data collection computer malfunction or consent withdrawal. Data were analyzed from 90 patients (44 standard and 46 advanced

  12. Integrated optical biosensor system (IOBS)

    Science.gov (United States)

    Grace, Karen M.; Sweet, Martin R.; Goeller, Roy M.; Morrison, Leland Jean; Grace, Wynne Kevin; Kolar, Jerome D.

    2007-10-30

    An optical biosensor has a first enclosure with a pathogen recognition surface, including a planar optical waveguide and grating located in the first enclosure. An aperture is in the first enclosure for insertion of sample to be investigated to a position in close proximity to the pathogen recognition surface. A laser in the first enclosure includes means for aligning and means for modulating the laser, the laser having its light output directed toward said grating. Detection means are located in the first enclosure and in optical communication with the pathogen recognition surface for detecting pathogens after interrogation by the laser light and outputting the detection. Electronic means is located in the first enclosure and receives the detection for processing the detection and outputting information on the detection, and an electrical power supply is located in the first enclosure for supplying power to the laser, the detection means and the electronic means.

  13. Overview of affinity biosensors in food analysis.

    Science.gov (United States)

    Patel, Pradip D

    2006-01-01

    The 4 major driving forces that are expected to lead to increased use of affinity biosensors that meet crucial industrial test specifications, e.g., fast, reliable, cost-effective, and use of low-skilled personnel, are (1) strict legislative framework, e.g., recent changes proposed to the European food safety and hygiene legislation, EC No. 178/2002; (2) industrial shift from quality control to quality assurance procedures, e.g., Hazard Analysis Critical Control Point, ensuring effective positioning in the global competitive trade; (3) just-in-time production resulting in 'right' product every time; and (4) consumer demand for safe and wholesome products. The affinity biosensors field has expanded significantly over the past decade, with a projected global biosensors market growth from $6.1 billion in 2004 to $8.2 billion in 2009, representing major industrial sectors (e.g., Pharma, Medicare, and Food). This brief review is targeted to affinity biosensors developed for the food industry and includes research and development leading to biosensors for microbiological and chemical analytes of industrial concern, commercial biosensors products on the market, and examples of future prospects in this diagnostic field. PMID:16792079

  14. Overview of affinity biosensors in food analysis.

    Science.gov (United States)

    Patel, Pradip D

    2006-01-01

    The 4 major driving forces that are expected to lead to increased use of affinity biosensors that meet crucial industrial test specifications, e.g., fast, reliable, cost-effective, and use of low-skilled personnel, are (1) strict legislative framework, e.g., recent changes proposed to the European food safety and hygiene legislation, EC No. 178/2002; (2) industrial shift from quality control to quality assurance procedures, e.g., Hazard Analysis Critical Control Point, ensuring effective positioning in the global competitive trade; (3) just-in-time production resulting in 'right' product every time; and (4) consumer demand for safe and wholesome products. The affinity biosensors field has expanded significantly over the past decade, with a projected global biosensors market growth from $6.1 billion in 2004 to $8.2 billion in 2009, representing major industrial sectors (e.g., Pharma, Medicare, and Food). This brief review is targeted to affinity biosensors developed for the food industry and includes research and development leading to biosensors for microbiological and chemical analytes of industrial concern, commercial biosensors products on the market, and examples of future prospects in this diagnostic field.

  15. Biosensor technology: technology push versus market pull.

    Science.gov (United States)

    Luong, John H T; Male, Keith B; Glennon, Jeremy D

    2008-01-01

    Biosensor technology is based on a specific biological recognition element in combination with a transducer for signal processing. Since its inception, biosensors have been expected to play a significant analytical role in medicine, agriculture, food safety, homeland security, environmental and industrial monitoring. However, the commercialization of biosensor technology has significantly lagged behind the research output as reflected by a plethora of publications and patenting activities. The rationale behind the slow and limited technology transfer could be attributed to cost considerations and some key technical barriers. Analytical chemistry has changed considerably, driven by automation, miniaturization, and system integration with high throughput for multiple tasks. Such requirements pose a great challenge in biosensor technology which is often designed to detect one single or a few target analytes. Successful biosensors must be versatile to support interchangeable biorecognition elements, and in addition miniaturization must be feasible to allow automation for parallel sensing with ease of operation at a competitive cost. A significant upfront investment in research and development is a prerequisite in the commercialization of biosensors. The progress in such endeavors is incremental with limited success, thus, the market entry for a new venture is very difficult unless a niche product can be developed with a considerable market volume. PMID:18577442

  16. Masters Thesis- Criticality Alarm System Design Guide with Accompanying Alarm System Development for the Radioisotope Production Laboratory in Richland, Washington

    Energy Technology Data Exchange (ETDEWEB)

    Greenfield, Bryce A. [Univ. of New Mexico, Albuquerque, NM (United States)

    2009-12-01

    A detailed instructional manual was created to guide criticality safety engineers through the process of designing a criticality alarm system (CAS) for Department of Energy (DOE) hazard class 1 and 2 facilities. Regulatory and technical requirements were both addressed. A list of design tasks and technical subtasks are thoroughly analyzed to provide concise direction for how to complete the analysis. An example of the application of the design methodology, the Criticality Alarm System developed for the Radioisotope Production Laboratory (RPL) of Richland, Washington is also included. The analysis for RPL utilizes the Monte Carlo code MCNP5 for establishing detector coverage in the facility. Significant improvements to the existing CAS were made that increase the reliability, transparency, and coverage of the system.

  17. Masters Thesis- Criticality Alarm System Design Guide with Accompanying Alarm System Development for the Radioisotope Production Laboratory in Richland, Washington

    Energy Technology Data Exchange (ETDEWEB)

    Greenfield, Bryce A.

    2009-12-20

    A detailed instructional manual was created to guide criticality safety engineers through the process of designing a criticality alarm system (CAS) for Department of Energy (DOE) hazard class 1 and 2 facilities. Regulatory and technical requirements were both addressed. A list of design tasks and technical subtasks are thoroughly analyzed to provide concise direction for how to complete the analysis. An example of the application of the design methodology, the Criticality Alarm System developed for the Radioisotope Production Laboratory (RPL) of Richland, Washington is also included. The analysis for RPL utilizes the Monte Carlo code MCNP5 for establishing detector coverage in the facility. Significant improvements to the existing CAS were made that increase the reliability, transparency, and coverage of the system.

  18. A multi-channel bioluminescent bacterial biosensor for the on-line detection of metals and toxicity. Part II: technical development and proof of concept of the biosensor

    Energy Technology Data Exchange (ETDEWEB)

    Charrier, Thomas; Thouand, Gerald [UMR CNRS 6144 GEPEA, CBAC, Nantes University, PRES UNAM, Campus de la Courtaisiere-IUT, La Roche-sur-Yon cedex (France); Chapeau, Cyrille [Biolumine, Biokar Diagnostic, Rue des Quarante Mines ZAC de Ther-Allonne, Beauvais Cedex (France); Bendria, Loubna; Daniel, Philippe [UMR CNRS 6087 LPEC, Universite du Maine, Av Olivier Messiaen, Le Mans cedex 9 (France); Picart, Pascal [UMR CNRS 6613 IAM-LAUM, Ecole Nationale des Ingenieurs du Mans, Universite du Maine, Le Mans Cedex 9 (France)

    2011-05-15

    This research study deals with the on-line detection of heavy metals and toxicity within the context of environmental pollution monitoring. It describes the construction and the proof of concept of a multi-channel bioluminescent bacterial biosensor in immobilized phase: Lumisens3. This new versatile device, designed for the non-stop analysis of water pollution, enables the insertion of any bioluminescent strains (inducible or constitutive), immobilized in a multi-well removable card. The technical design of Lumisens3 has benefited from both a classical and a robust approach and includes four main parts: (1) a dedicated removable card contains 64 wells, 3 mm in depth, arranged in eight grooves within which bacteria are immobilized, (2) this card is incubated on a Pelletier block with a CCD cooled camera on top for bioluminescence monitoring, (3) a fluidic network feeds the card with the sample to be analyzed and finally (4) a dedicated computer interface, BIOLUX 1.0, controls all the elements of the biosensor, allowing it to operate autonomously. The proof of concept of this biosensor was performed using a set of four bioluminescent bacteria (Escherichia coli DH1 pBzntlux, pBarslux, pBcoplux, and E. coli XL1 pBfiluxCDABE) in the on-line detection of CdCl{sub 2} 0.5 {mu}M and As{sub 2}O{sub 3} 5 {mu}M from an influent. When considering metals individually, the ''fingerprints'' from the biosensor were as expected. However, when metals were mixed together, cross reaction and synergistic effects were detected. This biosensor allowed us to demonstrate the simultaneous on-line cross detection of one or several heavy metals as well as the measurement of the overall toxicity of the sample. (orig.)

  19. Health and environment in Eastern Europe: an alarming diagnosis. Sante et environnement a l'Est: un diagnostic alarmant

    Energy Technology Data Exchange (ETDEWEB)

    Bonnefoy, X.

    1993-05-01

    Life-expectancy, infant and maternal mortality rates... the distance between East and West in increasing. Among the explanations: ways of life, systems of health care, socioeconomic situations or even historical fatality. But other factors can be pointed out: polluted air, water and soil - an environment whose deterioration is reason for alarm. International organizations have the job of making a diagnosis prior to any treatment.

  20. Reducing SCADA System Nuisance Alarms in the Water Industry in Northern Ireland

    OpenAIRE

    O'Donoghue, Nigel; Phillips, Debra H.; Nicell, Ciaran

    2015-01-01

    The advancement of telemetry control for the water industry has increased the difficulty of 14 managing large volumes of nuisance alarms (i.e. alarms that do not require a response). The aim 15 of this study was to identify and reduce the number of nuisance alarms that occur for Northern 16 Ireland (NI) Water by carrying-out alarm duration analysis to determine the appropriate length of 17 persistence (an advanced alarm management tool) that could be applied. All data was extracted 18 from Te...

  1. Design of Microcantilever-Based Biosensor with Digital Feedback Control Circuit

    Directory of Open Access Journals (Sweden)

    Jayu P. Kalambe

    2012-01-01

    Full Text Available This paper present the design of cantilever-based biosensors with new readout, which hold promises as fast and cheap “point of care” device as well as interesting research tools. The fabrication process and related issues of the cantilever based bio-sensor are discussed. Coventorware simulation is carried out to analyze the device behavior. A fully integrated control circuit has been designed to solve manufacturing challenge which will take care of positioning of the cantilever instead of creating nanometer gap between the electrodes. The control circuit will solve the manufacturing challenge faced by the readout methods where it is essential to maintain precise gap between the electrodes. The circuit can take care of variation obtained due to fabrication process and maintain the precise gap between the electrodes by electrostatic actuation. The control circuit consist of analog and digital modules. The reliability issues of the sensor are also discussed.

  2. A new diamond biosensor with integrated graphitic microchannels for detecting quantal exocytic events from chromaffin cells

    CERN Document Server

    Picollo, Federico; Vittone, Ettore; Pasquarelli, Alberto; Carbone, Emilio; Olivero, Paolo; Carabelli, Valentina

    2013-01-01

    The quantal release of catecholamines from neuroendocrine cells is a key mechanism which has been investigated with a broad range of materials and devices, among which carbon-based materials such as carbon fibers, diamond-like carbon, carbon nanotubes and nanocrystalline diamond. In the present work we demonstrate that a MeV-ion-microbeam lithographic technique can be successfully employed for the fabrication of an all-carbon miniaturized cellular bio-sensor based on graphitic micro-channels embedded in a single-crystal diamond matrix. The device was functionally characterized for the in vitro recording of quantal exocytic events from single chromaffin cells, with high sensitivity and signal-to-noise ratio, opening promising perspectives for the realization of monolithic all-carbon cellular biosensors.

  3. Disposable L-lactate biosensor based on a screen-printed carbon electrode enhanced by graphene

    International Nuclear Information System (INIS)

    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. (paper)

  4. Biosensor

    DEFF Research Database (Denmark)

    2002-01-01

    , food and feed preparations, tissue extracts, acyl-CoA synthetase reaction media and various laboratory conditions using a modified Coenzyme A- and acyl-CoA binding protein (ACBP) is provided. Furthermore the invention relates to a construct comprising a peptide and a signal moiety for performing...

  5. Microfluidic devices with integrated biosensors for biomedical applications

    OpenAIRE

    Parra Cabrera, César Alejandro

    2014-01-01

    In recent years, the LOC community has focused most of its research in the biomedical and biotechnology fields, due to the need of portable, low power consumption and low cost theranostics microdevices. Some developing countries do not have suitable medical diagnostics technologies and the supply and storage of the reagents is in many cases limited as well as the access to energy. Furthermore, developed countries are experimenting population aging needing novel low cost efficient disease-scre...

  6. Human factors engineering guidance for the review of advanced alarm systems

    International Nuclear Information System (INIS)

    This report provides guidance to support the review of the human factors aspects of advanced alarm system designs in nuclear power plants. The report is organized into three major sections. The first section describes the methodology and criteria that were used to develop the design review guidelines. Also included is a description of the scope, organization, and format of the guidelines. The second section provides a systematic review procedure in which important characteristics of the alarm system are identified, described, and evaluated. The third section provides the detailed review guidelines. The review guidelines are organized according to important characteristics of the alarm system including: alarm definition; alarm processing and reduction; alarm prioritization and availability; display; control; automated; dynamic, and modifiable characteristics; reliability, test, maintenance, and failure indication; alarm response procedures; and control-display integration and layout

  7. A High-confidence Cyber-Physical Alarm System: Design and Implementation

    CERN Document Server

    Ma, Longhua; Xia, Feng; Xu, Ming; Yao, Jun; Shao, Meng

    2010-01-01

    Most traditional alarm systems cannot address security threats in a satisfactory manner. To alleviate this problem, we developed a high-confidence cyber-physical alarm system (CPAS), a new kind of alarm systems. This system establishes the connection of the Internet (i.e. TCP/IP) through GPRS/CDMA/3G. It achieves mutual communication control among terminal equipments, human machine interfaces and users by using the existing mobile communication network. The CPAS will enable the transformation in alarm mode from traditional one-way alarm to two-way alarm. The system has been successfully applied in practice. The results show that the CPAS could avoid false alarms and satisfy residents' security needs.

  8. Human factors engineering guidance for the review of advanced alarm systems

    Energy Technology Data Exchange (ETDEWEB)

    O`Hara, J.M.; Brown, W.S.; Higgins, J.C.; Stubler, W.F. [Brookhaven National Lab., Upton, NY (United States)

    1994-09-01

    This report provides guidance to support the review of the human factors aspects of advanced alarm system designs in nuclear power plants. The report is organized into three major sections. The first section describes the methodology and criteria that were used to develop the design review guidelines. Also included is a description of the scope, organization, and format of the guidelines. The second section provides a systematic review procedure in which important characteristics of the alarm system are identified, described, and evaluated. The third section provides the detailed review guidelines. The review guidelines are organized according to important characteristics of the alarm system including: alarm definition; alarm processing and reduction; alarm prioritization and availability; display; control; automated; dynamic, and modifiable characteristics; reliability, test, maintenance, and failure indication; alarm response procedures; and control-display integration and layout.

  9. Nanotechnology-Based Surface Plasmon Resonance Affinity Biosensors for In Vitro Diagnostics

    Science.gov (United States)

    Antiochia, Riccarda; Bollella, Paolo; Favero, Gabriele

    2016-01-01

    In the last decades, in vitro diagnostic devices (IVDDs) became a very important tool in medicine for an early and correct diagnosis, a proper screening of targeted population, and also assessing the efficiency of a specific therapy. In this review, the most recent developments regarding different configurations of surface plasmon resonance affinity biosensors modified by using several nanostructured materials for in vitro diagnostics are critically discussed. Both assembly and performances of the IVDDs tested in biological samples are reported and compared. PMID:27594884

  10. Self-Assembled Films of Dendrimers and Metallophthalocyanines as FET-Based Glucose Biosensors

    OpenAIRE

    Alessandra Figueiredo; Alvaro A.A. de Queiroz; Guimarães, Francisco E.G.; Valtencir Zucolotto; Vieira, Nirton C. S.

    2011-01-01

    Separative extended gate field effect transistor (SEGFET) type devices have been used as an ion sensor or biosensor as an alternative to traditional ion sensitive field effect transistors (ISFETs) due to their robustness, ease of fabrication, low cost and possibility of FET isolation from the chemical environment. The layer-by-layer technique allows the combination of different materials with suitable properties for enzyme immobilization on simple platforms such as the extended gate of SEGFET...

  11. Nanotechnology-Based Surface Plasmon Resonance Affinity Biosensors for In Vitro Diagnostics.

    Science.gov (United States)

    Antiochia, Riccarda; Bollella, Paolo; Favero, Gabriele; Mazzei, Franco

    2016-01-01

    In the last decades, in vitro diagnostic devices (IVDDs) became a very important tool in medicine for an early and correct diagnosis, a proper screening of targeted population, and also assessing the efficiency of a specific therapy. In this review, the most recent developments regarding different configurations of surface plasmon resonance affinity biosensors modified by using several nanostructured materials for in vitro diagnostics are critically discussed. Both assembly and performances of the IVDDs tested in biological samples are reported and compared. PMID:27594884

  12. Novel fully-integrated biosensor for endotoxin detection via polymyxin B immobilization onto gold electrodes

    OpenAIRE

    A. Zuzuarregui; S. Arana; E. Pérez-Lorenzo; Sánchez-Gómez, S.; Martínez de Tejada, G.; Mujika, M.

    2013-01-01

    In this paper an electrochemical endotoxin biosensor consisting of an immobilized lipopolysaccharide (LPS) ligand, polymyxin B (PmB), is presented. Several parameters involved both in the device fabrication and in the detection process were analyzed to optimize the ligand immobilization and the interaction between PmB and LPS, aiming at increasing the sensitivity of the sensor. Different electrochemical pre-treatment procedures as well as the functionalization methods were s...

  13. An implantable multifunctional needle type biosensor with integrated RF capability.

    Science.gov (United States)

    Chiu, Nan-Fu; Wang, Jmin-Min; Yang, Lung-Jieh; Liao, Cheng-Wei; Chen, Chun-Hao; Chen, Hsiao-Chin; Lu, Shey-Shi; Lin, Chii-Wann

    2005-01-01

    We report the development of an implantable multifunctional (glucose and cholesterol) needle type biosensor with integrated RF wireless circuitry for continuous in vivo monitoring of metabolites during short term stays in emergency room or intensive care unit. Silicon-based MEMS technologies are used for the fabrication of micro needle sensors. The whole device is covered by a biocompatible Parylene layer with opening structure at the active areas of electrodes. Electropolymerization of active biomolecules and conducting polymer provides in situ nanoscale physical entrapments of various oxidoreductases (Glucose oxidase and cholesterol oxidase) and functions as a viable matrix for the construction of micro amperometric biosensors. Hybrid CMOS fabrication processes are used to accomplish the 433 MHz ASK RF transmitter and receiver (0.18μm CMOS 1P6M process) and the data converter (0.35μm CMOS 2P4M process). We will present and discuss the detail design and the integrated system performance in this paper. PMID:17282599

  14. Disposable biosensor for detection of iron (III) in wines.

    Science.gov (United States)

    Cámara-Martos, Fernando; da Costa, João; Justino, Celine I L; Cardoso, Susana; Duarte, Armando C; Rocha-Santos, Teresa

    2016-07-01

    This paper reports the tuning of a fast, disposable, and label-free biosensor for quantification of iron (III) in food liquid samples such as wine. The biosensor is based on a field effect transistor(FET) where a net work of single-walled carbonnanotubes (SWCNTs) acts as the conductor channel, constituting carbonnanotubes field effect transistors (CNTFETs). An antibody such as transferrin with two specific high-affinity iron (III) binding sites, directly adsorbed to SWCNTs, was used as immunoreaction. Several individual CNTFETs were tested showing a linear range between 0.05 and 2ngmL(-1) and a limit of quantification below 0.05ngmL(-1), much lower than previously reported analytical techniques. The mean coefficient of variation was 0.13% showing a low variability of the analytical response. On the other hand, it was not observed interference effect of zinc (II) ion at least until 1:4 iron-zinc ratio. Finally, recovery percentages of spiked wine samples were around 100%, showing the high accuracy of method. The main advantages of the devices developed are their speed, convenience (it is an economical method), and the avoidance excessive handling samples since they do not require further pre-treatment of samples. PMID:27154651

  15. 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

    2016-01-01

    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. PMID:26985910

  16. A new miniaturized multiarray biosensor system for fluorescence detection

    International Nuclear Information System (INIS)

    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 cm3) 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 mm3 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

  17. Optical biosensor based on silicon nanowire ridge waveguide

    Science.gov (United States)

    Gamal, Rania; Ismail, Yehia; Swillam, Mohamed A.

    2015-02-01

    Optical biosensors present themselves as an attractive solution for integration with the ever-trending lab-on-a-chip devices. This is due to their small size, CMOS compatibility, and invariance to electromagnetic interference. Despite their many benefits, typical optical biosensors rely on evanescent field detection, where only a small portion of the light interacts with the analyte. We propose to use a silicon nanowire ridge waveguide (SNRW) for optical biosensing. This structure is comprised of an array of silicon nanowires, with the envelope of a ridge, on an insulator substrate. The SNRW maximizes the overlap between the analyte and the incident light wave by introducing voids to the otherwise bulk structure, and strengthens the contribution of the material under test to the overall modal effective index will greatly augment the sensitivity. Additionally, the SNRW provides a fabrication convenience as it covers the entire substrate, ensuring that the etching process would not damage the substrate. FDTD simulations were conducted and showed that the percentage change in the effective index due to a 1% change in the surrounding environment was more than 170 times the amount of change perceived in an evanescent detection based bulk silicon ridge waveguide.

  18. A simple enzyme based biosensor on flexible plastic substrate

    Science.gov (United States)

    Kanakamedala, Senaka K.; Alshakhouri, Haidar T.; Agarwal, Mangilal; Fang, Ji; DeCoster, Mark A.

    2010-08-01

    An enzyme based biosensor was fabricated by employing a simple, inexpensive and rapid xurography fabrication process. The electrodes and channel were made from the conducting polymer poly(3,4-ethyelenedioxythiphene) poly(styrene sulfonate) (PEDOT:PSS). PEDOT:PSS was selectively deposited using a polyimide tape mask. The tape mask was peeled off from the substrate after annealing the polymer in vacuum. Polymer wells of defined dimensions were made and were attached to the device to accommodate the solutions. This sensor utilizes the change in current as a parameter to measure different analyte concentrations. Initial experiments were done by using the sensor for glucose detection. The sensor is able to detect the glucose concentrations approximately from 1 μM to 10 mM range covering glucose in human saliva (8-210 μM). The glucose oxidase activity was independently measured using colorimetric method and the results indicate that the sensor retains the enzyme activity and can be used as a biosensor to detect various analytes. The analyte of interest can be measured by preloading the corresponding enzyme into the wells.

  19. An experimental investigation of the effects of alarm processing and display on operator performance

    Energy Technology Data Exchange (ETDEWEB)

    O`Hara, J.; Brown, W. [Brookhaven National Lab., Upton, NY (United States). Dept. of Advanced Technology; Hallbert, B.; Skraaning, G. [Halden Reactor Project (Norway); Wachtel, J.; Persensky, J. [Nuclear Regulatory Commission, Washington, DC (United States). Office of Nuclear Regulatory Research

    1998-03-01

    This paper describes a research program sponsored by the US Nuclear Regulatory Commission to address the human factors engineering (HFE) aspects of nuclear power plant alarm systems. The overall objective of the program is to develop HFE review guidance for advanced alarm systems. As part of this program, guidance has been developed based on a broad base of technical and research literature. In the course of guidance development, aspects of alarm system design for which the technical basis was insufficient to support complete guidance development were identified. The primary purpose of the research reported in this paper was to evaluate the effects of three of these alarm system design characteristics on operator performance in order to contribute to the understanding of potential safety issues and to provide data to support the development of design review guidance in these areas. Three alarm system design characteristics studied were (1) alarm processing (degree of alarm reduction), (2) alarm availability (dynamic prioritization and suppression), and (3) alarm display (a dedicated tile format, a mixed tile and message list format, and a format in which alarm information is integrated into the process displays). A secondary purpose was to provide confirmatory evidence of selected alarm system guidance developed in an earlier phase of the project. The alarm characteristics were combined into eight separate experimental conditions. Six, two-person crews of professional nuclear power plant operators participated in the study. Following training, each crew completed 16 test trials which consisted of two trials in each of the eight experimental conditions (one with a low-complexity scenario and one with a high-complexity scenario). Measures of process performance, operator task performance, situation awareness, and workload were obtained. In addition, operator opinions and evaluations of the alarm processing and display conditions were collected. No deficient

  20. 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.

  1. SIRE-technology-based biosensors: will they do the job?

    Science.gov (United States)

    Kriz, Dario

    1997-06-01

    A new biosensor technology (SIRE--sensors based on injectable recognition elements) is described. Its application in laboratory equipment, medical survey equipment and process monitoring is reviewed. Furthermore, the promising practical and commercial relevance of SIRE- Biosensors is discussed.

  2. Graphene nano-ink biosensor arrays on a microfluidic paper for multiplexed detection of metabolites

    Energy Technology Data Exchange (ETDEWEB)

    Labroo, Pratima; Cui, Yue, E-mail: yue.cui@usu.edu

    2014-02-01

    Graphical abstract: - Highlights: • We report graphene-ink biosensor arrays on a microfluidic paper for metabolites. • The device is able to detect multiple metabolites sensitively and rapidly. • The device fabrication process is simple and inexpensive. - Abstract: The development of a miniaturized and low-cost platform for the highly sensitive, selective and rapid detection of multiplexed metabolites is of great interest for healthcare, pharmaceuticals, food science, and environmental monitoring. Graphene is a delicate single-layer, two-dimensional network of carbon atoms with extraordinary electrical sensing capability. Microfluidic paper with printing technique is a low cost matrix. Here, we demonstrated the development of graphene-ink based biosensor arrays on a microfluidic paper for the multiplexed detection of different metabolites, such as glucose, lactate, xanthine and cholesterol. Our results show that the graphene biosensor arrays can detect multiple metabolites on a microfluidic paper sensitively, rapidly and simultaneously. The device exhibits a fast measuring time of less than 2 min, a low detection limit of 0.3 μM, and a dynamic detection range of 0.3–15 μM. The process is simple and inexpensive to operate and requires a low consumption of sample volume. We anticipate that these results could open exciting opportunities for a variety of applications.

  3. A novel silicon based mags-biosensor for nucleic acid detection by magnetoelectronic transduction

    Directory of Open Access Journals (Sweden)

    Maria Eloisa Castagna

    2015-12-01

    Full Text Available We developed a novel silicon biosensor based on magnetoelectronic transduction (MAGS for nucleic acid detection. The mags-biosensor is a planar device composed by a primary micro-coil, and two secondary coils which produce a differential voltage due to the induced magnetic field. The presence of magnetic material over one of the secondary coils causes variations of induced magnetic field density that in turn results in a total output voltage different from zero. The voltage variation, therefore, is a measure of the amount of magnetic material present in the active zone. A device sensitivity of 5.1 mV/ng and a resolution of 0.008 ng have been observed. The biosensor also presents a micro-heater and a thermal sensor respectively to set and read-out the chip temperature: this aspect enables the device to be used for several biochemical applications that need temperature control and activation such for example nucleic acid amplification (real-time PCR, antigen- antibody detection (immune-assay and SNP detection.

  4. Graphene nano-ink biosensor arrays on a microfluidic paper for multiplexed detection of metabolites

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • We report graphene-ink biosensor arrays on a microfluidic paper for metabolites. • The device is able to detect multiple metabolites sensitively and rapidly. • The device fabrication process is simple and inexpensive. - Abstract: The development of a miniaturized and low-cost platform for the highly sensitive, selective and rapid detection of multiplexed metabolites is of great interest for healthcare, pharmaceuticals, food science, and environmental monitoring. Graphene is a delicate single-layer, two-dimensional network of carbon atoms with extraordinary electrical sensing capability. Microfluidic paper with printing technique is a low cost matrix. Here, we demonstrated the development of graphene-ink based biosensor arrays on a microfluidic paper for the multiplexed detection of different metabolites, such as glucose, lactate, xanthine and cholesterol. Our results show that the graphene biosensor arrays can detect multiple metabolites on a microfluidic paper sensitively, rapidly and simultaneously. The device exhibits a fast measuring time of less than 2 min, a low detection limit of 0.3 μM, and a dynamic detection range of 0.3–15 μM. The process is simple and inexpensive to operate and requires a low consumption of sample volume. We anticipate that these results could open exciting opportunities for a variety of applications

  5. Improved synthesis and growth of graphene oxide for field effect transistor biosensors.

    Science.gov (United States)

    Huang, Jingfeng; Chen, Hu; Jing, Lin; Fam, Derrick; Tok, Alfred Iing Yoong

    2016-08-01

    Reduced graphene oxide (RGO) has many advantages over graphene such as low-cost, aqueous processable and industrial-scalable. However, two main limitations that prevent the use of RGO in electronics are the high electrical resistance and large electrical resistance deviation between fabricated devices. This limits RGO's use in biosensors, capacitors and other electronic devices. Herein, we present (1) a modified Hummer's method to obtain large RGO flakes via in-situ size fractionation and (2) the novel growth of RGO which can bridge the gaps in-between existing RGO flakes. Together, these two processes reduced the electrical resistance drastically from 1.99E + 06 to 4.68E + 03 Ω/square and the standard deviation decreased from 80.5 % to 16.5 %. The RGO was then fabricated into a field-effect transistor biosensor. A 1 pmol to 100 nmol change in Cytochrome C protein corresponded to a 3 % change in electrical resistance. The reported improved RGO synthesis method and subsequent growth enable large-scale application of RGO in practical electronic devices such as biosensors. PMID:27379845

  6. Carbon Nanotubes Based Glucose Needle-type Biosensor

    OpenAIRE

    Hong Li; Yongquan Li; Minghao Sim; Wenjun Guan; Jinyan Jia

    2008-01-01

    A novel needle-type biosensor based on carbon nanotubes is reported. The biosensor was prepared by packing a mixture of multi-wall carbon nanotubes (MWCNTs), graphite powder and glucose oxidase (Gox) freeze-dried powder into a glass capillary of 0.5 mm inner diameter. The resulting amperometric biosensor was characterized electrochemically using amperometry in the presence of hydrogen peroxide and in the presence of glucose. The glucose biosensor sensitivity was influenced by the glucose oxid...

  7. Roughness effect on the efficiency of dimer antenna based biosensor

    OpenAIRE

    Dominique Barchiesi; Sameh Kessentini

    2012-01-01

    The fabrication process of nanodevices is continually improved. However, most of the nanodevices, such as biosensors present rough surfaces with mean roughness of some nanometers even if the deposition rate of material is more controlled. The effect of roughness on performance of biosensors was fully addressed for plane biosensors and gratings, but rarely addressed for biosensors based on Local Plasmon Resonance. The purpose of this paper is to evaluate numerically the influence of nanometric...

  8. TPLC-32 based alarm annunciation system for Dhruva

    International Nuclear Information System (INIS)

    The Control and Instrumentation (C and I) Systems of Dhruva Research Reactor have been designed in late seventies and are facing not only obsolescence but have limited diagnostic features. Since the expected life of C and I systems is typically twenty years, it was considered appropriate to upgrade some of the major systems including Alarm Annunciation System (AAS). The AAS of Dhruva is a Safety Class IB system that is used for processing alarm inputs and alerting the Main Control Room operator by driving LED based windows and audio annunciation in the Main Control Room. The AAS is also used for sequencing and logging of alarms on Operator Console. AAS is designed using qualified configurable platform Trombay Programmable Logic Controller-32 (TPLC-32) indigenously developed in BARC. The platform based design provides complete configurability, such that it can be used to build different systems for diverse applications. The AAS for Dhruva is first TPLC-32 based system to be deployed in any Indian Nuclear Reactor. The entire cycle involved conceptualization of system, making system requirement specifications, detailing the concept, design, fabrication, creation of test facilities, testing, validation of system performance, preparation of various documents for the regulatory safety clearances, installation and commissioning of the systems. This upgrade of AAS has helped enhancing safety, mitigates obsolescence and provided improved O and M features. Executing this upgrade in operating reactor posed additional constraints such as high level of safety, limited down time etc and this could be addressed through long term planning and implementation strategies based on innovative ideas and previous experience in installation and commissioning. Being an in-house product, long-term support for maintenance mitigating the obsolescence and technology up gradation is ensured. This paper provides technical information on AAS system design, its important features, the testing

  9. Detecting outliers in multivariate data while controlling false alarm rate

    Directory of Open Access Journals (Sweden)

    André Achim

    2012-06-01

    Full Text Available Outlier identification often implies inspecting each z-transformed variable and adding a Mahalanobis D^2. Multiple outliers may mask each other by increasing variance estimates. Caroni and Prescott (1992 proposed a multivariate extension of Rosner’s (1983 technique to circumvent masking, taking sample size into account to keep the false alarm risk below, say, alpha = .05. Simulations studies here compare the single multivariate approach to "multiple-univariate plus multivariate" tests, each at a Bonferroni corrected alpha level, in terms of power at detecting outliers. Results suggest the former is better only up to about 12 variables. Macros in an Excel spreadsheet implement these techniques.

  10. FRET Biosensors for Cancer Detection and Evaluation of Drug Efficacy

    OpenAIRE

    Lu, Shaoying; Wang, Yingxiao

    2010-01-01

    A sensitive and specific FRET biosensor was developed by Mizutani et al. and applied to detect the activity of BCR-ABL kinase in live cells. This biosensor allowed the detection of cancerous and drug-resistant cells, and the evaluation of kinase inhibitor efficacy. Future biosensor development and imaging can increasingly contribute to cancer diagnosis and therapeutics.

  11. A New Application of Carbon Nanotubes Constructing Biosensor

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Carbon nanotubes used for constructing biosensor was described for the first time. Single-wall carbon nanotubes (SWNTs) functionalized with carboxylic acid groups were used to immobilize glucose oxidase forming a glucose biosensor. The biosensor response can be determined by amperometric method at a low applied potential (0.40 V).

  12. 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.

  13. Changes are detected - cameras and video systems are monitoring the plant site, only rarely giving false alarm

    International Nuclear Information System (INIS)

    The main purpose of automatic data acquisition and processing for monitoring goals is to relieve the security personnel from monotonous observation tasks. The novel video systems can be programmed to detect moving target alarm signals, or accept alarm-suppressing image changes. This allows an intelligent alarm evaluation for physical protection in industry, differentiating between real and false alarm signals. (orig.)

  14. Fabrication of multianalyte CeO2 nanograin electrolyte–insulator–semiconductor biosensors by using CF4 plasma treatment

    Directory of Open Access Journals (Sweden)

    Chyuan Haur Kao

    2015-09-01

    Full Text Available Multianalyte CeO2 biosensors have been demonstrated to detect pH, glucose, and urine concentrations. To enhance the multianalyte sensing capability of these biosensors, CF4 plasma treatment was applied to create nanograin structures on the CeO2 membrane surface and thereby increase the contact surface area. Multiple material analyses indicated that crystallization or grainization caused by the incorporation of flourine atoms during plasma treatment might be related to the formation of the nanograins. Because of the changes in surface morphology and crystalline structures, the multianalyte sensing performance was considerably enhanced. Multianalyte CeO2 nanograin electrolyte–insulator–semiconductor biosensors exhibit potential for use in future biomedical sensing device applications.

  15. Design of the Intrinsically Safe Infrared Methane Alarm%本质安全型红外甲烷报警仪设计

    Institute of Scientific and Technical Information of China (English)

    王小珲; 王晶禹; 王丽; 梁庭

    2011-01-01

    The explosive gas atmosphere is a kind of particular working environment. Based on the principle of the infrared optical gas detection, and according to national standard of China, the intrinsic safety of the infrared methane alarm device was developed. The development was composed of the circuit design, the selection of the explosion-proof battery and the design of the flameproof crust. The device met the requirements for the underground use. The infrared detection principle of infrared methane alarm device and the chamber structure of the alarm instrument were also described. The overall design of the infrared methane alarm device features high security, portability, low power consumption and low voltage input.%针对爆炸性气体环境这种特殊的作业环境,基于红外光学气体检测原理,根据国家标准要求对红外甲烷报警仪进行本质安全的改进设计,其中主要包括依据国标要求对电路进行设计,防爆电池的选择以及隔爆外壳的设计,使其满足井下工作的要求.详细介绍了红外甲烷报警仪的工作原理、报警仪的气室结构等.红外甲烷报警仪的整体设计具有高安全性、便携式、低功率、低电压等特性,而且本质安全的设计给煤矿安全生产上了双保险,是一种安全可行的设计方案.

  16. 33 CFR 155.480 - Overfill devices.

    Science.gov (United States)

    2010-07-01

    ... overfill device that— (i) Meets the requirements of 46 CFR 39.20-7(b)(2) and (b)(3) and (d)(1) through (d... meets the requirements of 46 CFR 39.20-9(b); or (iii) Is an installed high level indicating device that... indicator for that tank) that meets the requirements for tank overfill alarms under 46 CFR 39.20-7(b)(2)...

  17. Characterization of Biosensors Based on Recombinant Glutamate Oxidase: Comparison of Crosslinking Agents in Terms of Enzyme Loading and Efficiency Parameters.

    Science.gov (United States)

    Ford, Rochelle; Quinn, Susan J; O'Neill, Robert D

    2016-01-01

    Amperometric l-glutamate (Glu) biosensors, based on both wild-type and a recombinant form of l-glutamate oxidase (GluOx), were designed and characterized in terms of enzyme-kinetic, sensitivity and stability parameters in attempts to fabricate a real-time Glu monitoring device suitable for future long-term detection of this amino acid in biological and other complex media. A comparison of the enzyme from these two sources showed that they were similar in terms of biosensor performance. Optimization of the loading of the polycationic stabilization agent, polyethyleneimine (PEI), was established before investigating a range of crosslinking agents under different conditions: glutaraldehyde (GA), polyethylene glycol (PEG), and polyethylene glycol diglycidyl ether (PEGDE). Whereas PEI-free biosensor designs lost most of their meager Glu sensitivity after one or two days, configurations with a 2:5 ratio of dip-evaporation applications of PEI(1%):GluOx(400 U/mL) displayed a 20-fold increase in their initial sensitivity, and a decay half-life extended to 10 days. All the crosslinkers studied had no effect on initial Glu sensitivity, but enhanced biosensor stability, provided the crosslinking procedure was carried out under well-defined conditions. The resulting biosensor design based on the recombinant enzyme deposited on a permselective layer of poly-(ortho-phenylenediamine), PoPD/PEI₂/GluOx₅/PEGDE, displayed good sensitivity (LOD term monitoring of Glu concentration dynamics in complex media.

  18. Impedance biosensor based on interdigitated electrode array for detection of E.coli O157:H7 in food products

    Science.gov (United States)

    Ghosh Dastider, Shibajyoti; Barizuddin, Syed; Dweik, Majed; Almasri, Mahmoud F.

    2012-05-01

    An impedance biosensor was designed, fabricated and tested for detection of viable Escherichia coli O157:H7 in food samples. This device consists of interdigitated microelectrode array (IDEA) fabricated using thin layer of sputtered gold, embedded under a polydimethylsiloxane (PDMS) microchannel. The array of electrodes is designed to detect viable EColi in different food products. The active surface area of the detection array was modified using goat anti-E.coli polyclonal IgG antibody. Contaminated food samples were tested by infusing the supernatant containing bacteria over the IDEA's, through the microchannel. Antibody-antigen binding on the electrodes results in impedance change. Four serial concentrations of E.coli contaminated food samples (3x102 CFUmL-1 to 3x105 CFUmL-1) were tested. The biosensor successfully detected the E.coli samples, with the lower detection limit being 3x103 CFUmL-1 (up to 3cells/μl). Comparing the test results with an IDEA impedance biosensor without microchannel (published elsewhere) indicates that this biosensor have two order of magnitude times higher sensitivity. The proposed biosensor provides qualitative and quantitative detection, and potentially could be used for detection of other type of bacteria by immobilizing the specific type of antibody.

  19. Concatenation of 'alert' and 'identity' segments in dingoes' alarm calls.

    Science.gov (United States)

    Déaux, Eloïse C; Allen, Andrew P; Clarke, Jennifer A; Charrier, Isabelle

    2016-01-01

    Multicomponent signals can be formed by the uninterrupted concatenation of multiple call types. One such signal is found in dingoes, Canis familiaris dingo. This stereotyped, multicomponent 'bark-howl' vocalisation is formed by the concatenation of a noisy bark segment and a tonal howl segment. Both segments are structurally similar to bark and howl vocalisations produced independently in other contexts (e.g. intra- and inter-pack communication). Bark-howls are mainly uttered in response to human presence and were hypothesized to serve as alarm calls. We investigated the function of bark-howls and the respective roles of the bark and howl segments. We found that dingoes could discriminate between familiar and unfamiliar howl segments, after having only heard familiar howl vocalisations (i.e. different calls). We propose that howl segments could function as 'identity signals' and allow receivers to modulate their responses according to the caller's characteristics. The bark segment increased receivers' attention levels, providing support for earlier observational claims that barks have an 'alerting' function. Lastly, dingoes were more likely to display vigilance behaviours upon hearing bark-howl vocalisations, lending support to the alarm function hypothesis. Canid vocalisations, such as the dingo bark-howl, may provide a model system to investigate the selective pressures shaping complex communication systems. PMID:27460289

  20. Highly Sensitive Nanoparticle-based Multifunctional Biosensor for Antigen Detection

    Science.gov (United States)

    Siavoshi, Salome

    electrophoresis technique to assemble the cancer specific anti-PSA, mAb-2C5 and CEA coated nanoparticles to show that the nanoparticle-based biochip can successfully measure low concentrations of various antigen. The principle of operation of these biosensors is the fluorescence based ELISA. Testing results of the nanoparticle-based biochips indicate very high specificity and the detection limit 200 times smaller than the commercially available devices for antigen detection, laying the foundation for early detection of various diseases. The optimized assembly of antibody coated particles and selective assembly techniques introduced in this work provide the necessary tools for fabricating a miniaturized nanoparticle-based in-vivo multiplex biosensor. The antigen detection results show the great potential for early detection of various diseases using the fabricated in-vivo device.

  1. 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.

  2. Lab-on-a-chip based biosensor for the real-time detection of aflatoxin.

    Science.gov (United States)

    Uludag, Yıldız; Esen, Elif; Kokturk, Guzin; Ozer, Hayrettin; Muhammad, Turghun; Olcer, Zehra; Basegmez, H Imge Oktay; Simsek, Senay; Barut, Serkan; Gok, M Yagmur; Akgun, Mete; Altintas, Zeynep

    2016-11-01

    Polymers were synthesized and utilized for aflatoxin detection coupled with a novel lab-on-a-chip biosensor: MiSens and high performance liquid chromatography (HPLC). Non-imprinted polymers (NIPs) were preferred to be designed and used due to the toxic nature of aflatoxin template and also to avoid difficult clean-up protocols. Towards an innovative miniaturized automated system, a novel biochip has been designed that consists of 6 working electrodes (1mm diameter) with shared reference and counter electrodes. The aflatoxin detection has been achieved by a competition immunoassay that has been performed using the new biochips and the automated MiSens electrochemical biosensor device. For the assay, aflatoxin antibody has been captured on the Protein A immobilized electrode. Subsequently the sample and the enzyme-aflatoxin conjugate mixture has been injected to the electrode surfaces. The final injection of the enzyme substrate results in an amperometric signal. The sensor assays for aflatoxin B1 (AFB1) in different matrices were also performed using enzyme link immunosorbent assay (ELISA) and HPLC for confirmation. High recovery was successfully achieved in spiked wheat samples using NIP coupled HPLC and NIP coupled MiSens biosensor [2ppb of aflatoxin was determined as 1.86ppb (93% recovery), 1.73ppb (86.5% recovery), 1.96ppb (98% recovery) and 1.88ppb (94.0% recovery) for immunoaffinity column (IAC)-HPLC, NIP-HPLC, Supel™ Tox SPE Cartridges (SUP)-HPLC and NIP-MiSens, respectively]. Aflatoxin detection in fig samples were also investigated with MiSens biosensor and the results were compared with HPLC method. The new biosensor allows real-time and on-site detection of AFB1 in foods with a rapid, sensitive, fully automated and miniaturized system and expected to have an immense economic impact for food industry. PMID:27591628

  3. Droplet-based microscale colorimetric biosensor for multiplexed DNA analysis via a graphene nanoprobe

    International Nuclear Information System (INIS)

    Graphical abstract: With a microvalve manipulate technique combined with droplet platform, a microscale fluorescence-based colorimetric sensor for multiplexed DNA analysis is developed via a graphene nanoprobe. Highlights: ► A quantitative detection for multiplexed DNA is first realized on droplet platform. ► The DNA detection is relied on a simple fluorescence-based colorimetric method. ► GO is served as a quencher for two different DNA fluorescent probes. ► This present work provides a rapid, sensitive, visual and convenient detection tool for droplet biosensor. - Abstract: The development of simple and inexpensive DNA detection strategy is very significant for droplet-based microfluidic system. Here, a droplet-based biosensor for multiplexed DNA analysis is developed with a common imaging device by using fluorescence-based colorimetric method and a graphene nanoprobe. With the aid of droplet manipulation technique, droplet size adjustment, droplet fusion and droplet trap are realized accurately and precisely. Due to the high quenching efficiency of graphene oxide (GO), in the absence of target DNAs, the droplet containing two single-stranded DNA probes and GO shows dark color, in which the DNA probes are labeled carboxy fluorescein (FAM) and 6-carboxy-X-rhodamine (ROX), respectively. The droplet changes from dark to bright color when the DNA probes form double helix with the specific target DNAs leading to the dyes far away from GO. This colorimetric droplet biosensor exhibits a quantitative capability for simultaneous detection of two different target DNAs with the detection limits of 9.46 and 9.67 × 10−8 M, respectively. It is also demonstrated that this biosensor platform can become a promising detection tool in high throughput applications with low consumption of reagents. Moreover, the incorporation of graphene nanoprobe and droplet technique can drive the biosensor field one more step to some extent.

  4. Developing Biosensors in Developing Countries: South Africa as a Case Study.

    Science.gov (United States)

    Fogel, Ronen; Limson, Janice

    2016-03-01

    A mini-review of the reported biosensor research occurring in South Africa evidences a strong emphasis on electrochemical sensor research, guided by the opportunities this transduction platform holds for low-cost and robust sensing of numerous targets. Many of the reported publications centre on fundamental research into the signal transduction method, using model biorecognition elements, in line with international trends. Other research in this field is spread across several areas including: the application of nanotechnology; the identification and validation of biomarkers; development and testing of biorecognition agents (antibodies and aptamers) and design of electro-catalysts, most notably metallophthalocyanine. Biosensor targets commonly featured were pesticides and metals. Areas of regional import to sub-Saharan Africa, such as HIV/AIDs and tuberculosis diagnosis, are also apparent in a review of the available literature. Irrespective of the targets, the challenge to the effective deployment of such sensors remains shaped by social and economic realities such that the requirements thereof are for low-cost and universally easy to operate devices for field settings. While it is difficult to disentangle the intertwined roles of national policy, grant funding availability and, certainly, of global trends in shaping areas of emphasis in research, most notable is the strong role that nanotechnology, and to a certain extent biotechnology, plays in research regarding biosensor construction. Stronger emphasis on collaboration between scientists in theoretical modelling, nanomaterials application and or relevant stakeholders in the specific field (e.g., food or health monitoring) and researchers in biosensor design may help evolve focused research efforts towards development and deployment of low-cost biosensors. PMID:26848700

  5. Developing Biosensors in Developing Countries: South Africa as a Case Study

    Directory of Open Access Journals (Sweden)

    Ronen Fogel

    2016-02-01

    Full Text Available A mini-review of the reported biosensor research occurring in South Africa evidences a strong emphasis on electrochemical sensor research, guided by the opportunities this transduction platform holds for low-cost and robust sensing of numerous targets. Many of the reported publications centre on fundamental research into the signal transduction method, using model biorecognition elements, in line with international trends. Other research in this field is spread across several areas including: the application of nanotechnology; the identification and validation of biomarkers; development and testing of biorecognition agents (antibodies and aptamers and design of electro-catalysts, most notably metallophthalocyanine. Biosensor targets commonly featured were pesticides and metals. Areas  of regional import to sub-Saharan Africa, such as HIV/AIDs and tuberculosis diagnosis, are also apparent in a review of the available literature. Irrespective of the targets, the challenge to the effective deployment of such sensors remains shaped by social and economic realities such that the requirements thereof are for low-cost and universally easy to operate devices for field settings. While it is difficult to disentangle the intertwined roles of national policy, grant funding availability and, certainly, of global trends in shaping areas of emphasis in research, most notable is the strong role that nanotechnology, and to a certain extent biotechnology, plays in research regarding biosensor construction. Stronger emphasis on collaboration between scientists in theoretical modelling, nanomaterials application and or relevant stakeholders in the specific field (e.g., food or health monitoring and researchers in biosensor design may help evolve focused research efforts towards development and deployment of low-cost biosensors.

  6. A Novel Cell-Based Hybrid Acoustic Wave Biosensor with Impedimetric Sensing Capabilities

    Directory of Open Access Journals (Sweden)

    Ioana Voiculescu

    2013-03-01

    Full Text Available A novel multiparametric biosensor system based on living cells will be presented. The biosensor system includes two biosensing techniques on a single device: resonant frequency measurements and electric cell-substrate impedance sensing (ECIS. The multiparametric sensor system is based on the innovative use of the upper electrode of a quartz crystal microbalance (QCM resonator as working electrode for the ECIS technique. The QCM acoustic wave sensor consists of a thin AT-cut quartz substrate with two gold electrodes on opposite sides. For integration of the QCM with the ECIS technique a semicircular counter electrode was fabricated near the upper electrode on the same side of the quartz crystal. Bovine aortic endothelial live cells (BAECs were successfully cultured on this hybrid biosensor. Finite element modeling of the bulk acoustic wave resonator using COMSOL simulations was performed. Simultaneous gravimetric and impedimetric measurements performed over a period of time on the same cell culture were conducted to validate the device’s sensitivity. The time necessary for the BAEC cells to attach and form a compact monolayer on the biosensor was 35~45 minutes for 1.5 × 104 cells/cm2 BAECs; 60 minutes for 2.0 × 104 cells/cm2 BAECs; 70 minutes for 3.0 × 104 cells/cm2 BAECs; and 100 minutes for 5.0 × 104 cells/cm2 BAECs. It was demonstrated that this time is the same for both gravimetric and impedimetric measurements. This hybrid biosensor will be employed in the future for water toxicity detection.

  7. Biotelemetric Monitoring of Brain Neurochemistry in Conscious Rats Using Microsensors and Biosensors

    OpenAIRE

    Desole, Maria S; Robert D. O’Neill; Lowry, John P.; Vittorio Mazzarello; Gianfranco Bazzu; Ylenia Spissu; Giulia Puggioni; Rossana Migheli; Gaia Rocchitta; Giammario Calia; Serra, Pier A.

    2009-01-01

    In this study we present the real-time monitoring of three key brain neurochemical species in conscious rats using implantable amperometric electrodes interfaced to a biotelemetric device. The new system, derived from a previous design, was coupled with carbon-based microsensors and a platinum-based biosensor for the detection of ascorbic acid (AA), O2 and glucose in the striatum of untethered, freely-moving rats. The miniaturized device consisted of a single-supply sensor driver, a current-t...

  8. New directions in medical biosensors employing poly(3,4-ethylenedioxy thiophene) derivative-based electrodes

    DEFF Research Database (Denmark)

    Rozlosnik, Noemi

    2009-01-01

    Demand is growing in the field of medical diagnostics for simple, disposable devices that also demonstrate fast response times, are easy to handle, are cost-efficient, and are suitable for mass production. Polymer-based microfluidic devices meet the requirements of cost efficiency and mass...... production and they are suitable for biosensor applications. Conducting polymer-based electrochemical sensors have shown numerous advantages in a number of areas related to human health, such as the diagnosis of infectious diseases, genetic mutations, drug discovery, forensics and food technology, due...

  9. Microfabricated glucose biosensor for culture well operation.

    Science.gov (United States)

    Pemberton, R M; Cox, T; Tuffin, R; Sage, I; Drago, G A; Biddle, N; Griffiths, J; Pittson, R; Johnson, G; Xu, J; Jackson, S K; Kenna, G; Luxton, R; Hart, J P

    2013-04-15

    A water-based carbon screen-printing ink formulation, containing the redox mediator cobalt phthalocyanine (CoPC) and the enzyme glucose oxidase (GOx), was investigated for its suitability to fabricate glucose microbiosensors in a 96-well microplate format: (1) the biosensor ink was dip-coated onto a platinum (Pt) wire electrode, leading to satisfactory amperometric performance; (2) the ink was deposited onto the surface of a series of Pt microelectrodes (10-500 μm diameter) fabricated on a silicon substrate using MEMS (microelectromechanical systems) microfabrication techniques: capillary deposition proved to be successful; a Pt microdisc electrode of ≥100 μm was required for optimum biosensor performance; (3) MEMS processing was used to fabricate suitably sized metal (Pt) tracks and pads onto a silicon 96 well format base chip, and the glucose biosensor ink was screen-printed onto these pads to create glucose microbiosensors. When formed into microwells, using a 340 μl volume of buffer, the microbiosensors produced steady-state amperometric responses which showed linearity up to 5 mM glucose (CV=6% for n=5 biosensors). When coated, using an optimised protocol, with collagen in order to aid cell adhesion, the biosensors continued to show satisfactory performance in culture medium (linear range to 2 mM, dynamic range to 7 mM, CV=5.7% for n=4 biosensors). Finally, the operation of these collagen-coated microbiosensors, in 5-well 96-well format microwells, was tested using a 5-channel multipotentiostat. A relationship between amperometric response due to glucose, and cell number in the microwells, was observed. These results indicate that microphotolithography and screen-printing techniques can be combined successfully to produce microbiosensors capable of monitoring glucose metabolism in 96 well format cell cultures. The potential application areas for these microbiosensors are discussed. PMID:23265827

  10. Development of oxidoreductase based electrochemical biosensors

    OpenAIRE

    Rodrigues, Patrícia Raquel dos Santos

    2013-01-01

    Dissertação para obtenção do Grau de Mestre em Biotecnologia This thesis is divided in 2 sections, each describing the development of an oxidoreductase based biosensor. In the first part human Cytochrome P450 1A2 (CYP1A2) electrochemistry was studied, while the second is focused on the optimization of immobilization platforms and operation methods for amperometric biosensors, using cytochrome c nitrite reductase (ccNiR), (Desulfovibrio desulfuricans ATCC 27774) as a model enzyme. The...

  11. Biosensors for Inorganic and Organic Arsenicals

    Directory of Open Access Journals (Sweden)

    Jian Chen

    2014-11-01

    Full Text Available Arsenic is a natural environmental contaminant to which humans are routinely exposed and is strongly associated with human health problems, including cancer, cardiovascular and neurological diseases. To date, a number of biosensors for the detection of arsenic involving the coupling of biological engineering and electrochemical techniques has been developed. The properties of whole-cell bacterial or cell-free biosensors are summarized in the present review with emphasis on their sensitivity and selectivity. Their limitations and future challenges are highlighted.

  12. Intelligent alarms detection for the analysis of system fault impact on business

    OpenAIRE

    Pace, C.; Russo, I; Fernández, V.; Britos, Paola Verónica; Rossi, Bibiana D.; García Martínez, Ramón

    1998-01-01

    The tools for fault impact analysis are important for the deployment of critical mission systems. These tools can be also used as a development phase aid. We introduce several concepts related to "business alarms". Business alarms are an approximation to the company's business conceptual scheme driven by the business rules from systems conceptual schemes. In order to specify them we propose the utilization of Knowledge Engineering typical techniques. The object of alarm detection for impa...

  13. Mathematical Model of the Biosensors Acting in a Trigger Mode

    Science.gov (United States)

    Baronas, Romas; Kulys, Juozas; Ivanauskas, Feliksas

    2004-01-01

    A mathematical model of biosensors acting in a trigger mode has been developed. One type of the biosensors utilized a trigger enzymatic reaction followed by the cyclic enzymatic and electrochemical conversion of the product (CCE scheme). Other biosensors used the enzymatic trigger reaction followed by the electrochemical and enzymatic product cyclic conversion (CEC scheme). The models were based on diffusion equations containing a non-linear term related to Michaelis-Menten kinetics of the enzymatic reactions. The digital simulation was carried out using the finite difference technique. The influence of the substrate concentration, the maximal enzymatic rate as well as the membrane thickness on the biosensor response was investigated. The numerical experiments demonstrated a significant gain (up to dozens of times) in biosensor sensitivity when the biosensor response was under diffusion control. In the case of significant signal amplification, the response time with triggering was up to several times longer than that of the biosensor without triggering.

  14. Mathematical Model of the Biosensors Acting in a Trigger Mode

    Directory of Open Access Journals (Sweden)

    Feliksas Ivanauskas

    2004-05-01

    Full Text Available Abstract: A mathematical model of biosensors acting in a trigger mode has been developed. One type of the biosensors utilized a trigger enzymatic reaction followed by the cyclic enzymatic and electrochemical conversion of the product (CCE scheme. Other biosensors used the enzymatic trigger reaction followed by the electrochemical and enzymatic product cyclic conversion (CEC scheme. The models were based on diffusion equations containing a non-linear term related to Michaelis-Menten kinetics of the enzymatic reactions. The digital simulation was carried out using the finite difference technique. The influence of the substrate concentration, the maximal enzymatic rate as well as the membrane thickness on the biosensor response was investigated. The numerical experiments demonstrated a significant gain (up to dozens of times in biosensor sensitivity when the biosensor response was under diffusion control. In the case of significant signal amplification, the response time with triggering was up to several times longer than that of the biosensor without triggering.

  15. Self-assembled films of dendrimers and metallophthalocyanines as FET-based glucose biosensors.

    Science.gov (United States)

    Vieira, Nirton C S; Figueiredo, Alessandra; de Queiroz, Alvaro A A; Zucolotto, Valtencir; Guimarães, Francisco E G

    2011-01-01

    Separative extended gate field effect transistor (SEGFET) type devices have been used as an ion sensor or biosensor as an alternative to traditional ion sensitive field effect transistors (ISFETs) due to their robustness, ease of fabrication, low cost and possibility of FET isolation from the chemical environment. The layer-by-layer technique allows the combination of different materials with suitable properties for enzyme immobilization on simple platforms such as the extended gate of SEGFET devices enabling the fabrication of biosensors. Here, glucose biosensors based on dendrimers and metallophthalocyanines (MPcs) in the form of layer-by-layer (LbL) films, assembled on indium tin oxide (ITO) as separative extended gate material, has been produced. NH(3)(+) groups in the dendrimer allow electrostatic interactions or covalent bonds with the enzyme (glucose oxidase). Relevant parameters such as optimum pH, buffer concentration and presence of serum bovine albumin (BSA) in the immobilization process were analyzed. The relationship between the output voltage and glucose concentration shows that upon detection of a specific analyte, the sub-products of the enzymatic reaction change the pH locally, affecting the output signal of the FET transducer. In addition, dendritic layers offer a nanoporous environment, which may be permeable to H(+) ions, improving the sensibility as modified electrodes for glucose biosensing. PMID:22163704

  16. Self-Assembled Films of Dendrimers and Metallophthalocyanines as FET-Based Glucose Biosensors

    Directory of Open Access Journals (Sweden)

    Alessandra Figueiredo

    2011-10-01

    Full Text Available Separative extended gate field effect transistor (SEGFET type devices have been used as an ion sensor or biosensor as an alternative to traditional ion sensitive field effect transistors (ISFETs due to their robustness, ease of fabrication, low cost and possibility of FET isolation from the chemical environment. The layer-by-layer technique allows the combination of different materials with suitable properties for enzyme immobilization on simple platforms such as the extended gate of SEGFET devices enabling the fabrication of biosensors. Here, glucose biosensors based on dendrimers and metallophthalocyanines (MPcs in the form of layer-by-layer (LbL films, assembled on indium tin oxide (ITO as separative extended gate material, has been produced. NH3+ groups in the dendrimer allow electrostatic interactions or covalent bonds with the enzyme (glucose oxidase. Relevant parameters such as optimum pH, buffer concentration and presence of serum bovine albumin (BSA in the immobilization process were analyzed. The relationship between the output voltage and glucose concentration shows that upon detection of a specific analyte, the sub-products of the enzymatic reaction change the pH locally, affecting the output signal of the FET transducer. In addition, dendritic layers offer a nanoporous environment, which may be permeable to H+ ions, improving the sensibility as modified electrodes for glucose biosensing.

  17. Advanced alarm system design and human performance: Guidance development and current research

    International Nuclear Information System (INIS)

    This paper describes a research program sponsored by the U.S. Nuclear Regulatory Commission to address the human factors engineering (HFE) aspects of nuclear power plant alarm systems. The overall objective of the program is to develop HFE review guidance for advanced alarm systems. Guidance has been developed based on a broad base of technical and research literature. As part of the development effort, aspects of alarm system design for which the technical basis was insufficient to support guidance development were identified and prioritized. Research is currently underway to address the highest priority topics: alarm processing and display characteristics. (author). 29 refs, 2 figs

  18. Accident alarm equipment for steam generator, especially liquid sodium heated steam generator

    International Nuclear Information System (INIS)

    The alarm equipment consists of a system of sensors mounted onto the steam generator and its accessories. Each of the sensors is used for a different accident characteristic, such as the flow of sodium, the acoustic spectrum, the concentration of hydrogen in sodium. The system of sensors is connected to the common accident alarm system. The equipment will not issue the alarm signal if it receives a message from only one sensor, only when the message is confirmed from other sensors. This excludes false alarm. (M.D.)

  19. Biosensor Systems for Homeland Security

    Energy Technology Data Exchange (ETDEWEB)

    Bruckner-Lea, Cindy J.

    2004-05-30

    The detection of biological agents is important to minimize the effects of pathogens that can harm people, livestock, or plants. In addition to pathogens distributed by man, there is a need to detect natural outbreaks. Recent outbreaks of SARS, mad cow disease, pathogenic E. coli and Salmonella, as well as the discovery of letters filled with anthrax spores have highlighted the need for biosensor systems to aid in prevention, early warning, response, and recovery. Rapid detection can be used to prevent exposure; and detection on a longer timescale can be used to minimize exposure, define treatment, and determine whether contaminated areas are clean enough for reuse. The common types of biological agents of concern include bacteria, spores, and viruses (Figure 1). From a chemist’s point of view, pathogens are essentially complex packages of chemicals that are assembled into organized packages with somewhat predictable physical characteristics such as size and shape. Pathogen detection methods can be divided into three general approaches: selective detection methods for specific identification such as nucleic acid analysis and structural recognition, semi-selective methods for broad-spectrum detection (e.g. physical properties, metabolites, lipids), and function-based methods (e.g. effect of the pathogen on organisms, tissues, or cells). The requirements for biodetection systems depend upon the application. While detect to warn sensors may require rapid detection on the order one minute, detection times of many minutes or hours may be suitable for determining appropriate treatments or for forensic analysis. Of course ideal sensor systems will meet the needs of many applications, and will be sensitive, selective, rapid, and simultaneously detect all agents of concern. They will also be reliable with essentially no false negatives or false positives, small, easy to use, and low cost with minimal consumables.

  20. Reducing the temperature sensitivity of SOI waveguide-based biosensors

    Science.gov (United States)

    Gylfason, Kristinn B.; Mola Romero, Albert; Sohlström, Hans

    2012-06-01

    Label-free photonic biosensors fabricated on silicon-on-insulator (SOI) can provide compact size, high evanescent field strength at the silicon waveguide surface, and volume fabrication potential. However, due to the large thermo optic coefficient of water-based biosamples, the sensors are temperature-sensitive. Consequently, active temperature control is usually used. However, for low cost applications, active temperature control is often not feasible. Here, we use the opposite polarity of the thermo-optic coefficients of silicon and water to demonstrate a photonic slot waveguide with a distribution of power between sample and silicon that aims to give athermal operation in water. Based on simulations, we made three waveguide designs close to the athermal point, and asymmetric integrated Mach- Zehnder interferometers for their characterization. The devices were fabricated on SOI with a 220 nm device layer and 2 μm buried oxide, by electron beam lithography of hydrogen silsesquioxane (HSQ) resist, and etching in a Cl2/HBr/O2/He plasma. With Cargile 50350 fused silica matching oil as top cladding, the group index of the three guides varies from 1.9 to 2.8 at 1550 nm. The temperature sensitivity of the devices varied from -70 to -160 pm/K under the same conditions. A temperature sensitivity of -2 pm/K is projected with water as top cladding.

  1. Glucose biosensors based on a gold nanodendrite modified screen-printed electrode

    International Nuclear Information System (INIS)

    In this study, an enzymatic glucose biosensor based on a three-dimensional gold nanodendrite (GND) modified screen-printed electrode was developed. The GNDs were electrochemically synthesized on the working electrode component of a commercially available screen-printed electrode using a solution acquired by dissolving bulk gold in aqua regia as the precursor. The 3D GND electrode greatly enhanced the effective sensing area of the biosensor, which improved the sensitivity of glucose detection. Actual glucose detections demonstrated that the fabricated devices could perform at a sensitivity of 46.76 μA mM−1 cm−2 with a linear detection range from 28 μM–8.4 mM and detection limit of 7 μM. A fast response time (∼3 s) was also observed. Moreover, only a 20 μl glucose oxidase is required for detection owing to the incorporation of the commercially available screen-printed electrode. (paper)

  2. Protein-Based Graphene Biosensors: Optimizing Artificial Chemoreception in Bilayer Lipid Membranes.

    Science.gov (United States)

    Siontorou, Christina G; Georgopoulos, Konstantinos N; Nikoleli, Georgia-Paraskevi; Nikolelis, Dimitrios P; Karapetis, Stefanos K; Bratakou, Spyridoula

    2016-01-01

    Proteinaceous moieties are critical elements in most detection systems, including biosensing platforms. Their potential is undoubtedly vast, yet many issues regarding their full exploitation remain unsolved. On the other hand, the biosensor formats with the higher marketability probabilities are enzyme in nature and electrochemical in concept. To no surprise, alternative materials for hosting catalysis within an electrode casing have received much attention lately to demonstrate a catalysis-coated device. Graphene and ZnO are presented as ideal materials to modify electrodes and biosensor platforms, especially in protein-based detection. Our group developed electrochemical sensors based on these nanomaterials for the sensitive detection of cholesterol using cholesterol oxidase incorporated in stabilized lipid films. A comparison between the two platforms is provided and discussed. In a broader sense, the not-so-remote prospect of quickly assembling a protein-based flexible biosensing detector to fulfill site-specific requirements is appealing to both university researchers and industry developers. PMID:27618113

  3. Sensitivity and detection limit of dual-waveguide coupled microring resonator biosensors

    Institute of Scientific and Technical Information of China (English)

    Zhixuan Xia; Huaxiang Yi; Yao Chen; Zhiping Zhou

    2009-01-01

    We show that a linear relation exists between the device sensitivity and the quality (Q) factor of a dual-waveguide coupled microring resonator optical biosensor when the optimal conditions are satisfied. We also show that the detection limit depends on the loss coefficient and signal-to-nosie ratio (SNR) of the overall system, rather than the circumference of the ring. For a microring resonator sensor whose Q factor is 20000, the detection limit is found to be about 10-7 with 30-dB SNR, which is in good agreement with reported experimental data. These results indicate that loss reduction is the top priority in the design and fabrication of highly sensitive microring resonator optical biosensors.

  4. Lead-Free Piezoelectric Diaphragm Biosensors Based on Micro-Machining Technology and Chemical Solution Deposition.

    Science.gov (United States)

    Li, Xiaomeng; Wu, Xiaoqing; Shi, Peng; Ye, Zuo-Guang

    2016-01-12

    In this paper, we present a new approach to the fabrication of integrated silicon-based piezoelectric diaphragm-type biosensors by using sodium potassium niobate-silver niobate (0.82KNN-0.18AN) composite lead-free thin film as the piezoelectric layer. The piezoelectric diaphragms were designed and fabricated by micro-machining technology and chemical solution deposition. The fabricated device was very sensitive to the mass changes caused by various targets attached on the surface of diaphragm. The measured mass sensitivity value was about 931 Hz/μg. Its good performance shows that the piezoelectric diaphragm biosensor can be used as a cost-effective platform for nucleic acid testing.

  5. 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.

  6. Carbon nanomaterial-based electrochemical biosensors for label-free sensing of environmental pollutants.

    Science.gov (United States)

    Ramnani, Pankaj; Saucedo, Nuvia M; Mulchandani, Ashok

    2016-01-01

    Carbon allotropes such as graphene and carbon nanotubes, have been incorporated in electrochemical biosensors for highly sensitive and selective detection of various analytes. The superior physical and electrical properties like high carrier mobility, ambipolar electric field effect, high surface area, flexibility and their compatibility with microfabrication techniques makes these carbon nanomaterials easy to integrate in field-effect transistor (FET)/chemiresistor type configuration which is suitable for portable and point-of-use/field-deployable sensors. This review covers the synthesis of carbon nanostructures (graphene and CNTs) and their integration into devices using various fabrication methods. Finally, we discuss the recent reports showing different sensing platforms that incorporate biomolecules like enzymes, antibodies and aptamers as recognition elements for fabrication of simple, low cost, compact biosensors that can be used for on-site, rapid environmental monitoring of environmental pollutants like pathogens, heavy metals, pesticides and explosives.

  7. Carbon nanomaterial-based electrochemical biosensors for label-free sensing of environmental pollutants.

    Science.gov (United States)

    Ramnani, Pankaj; Saucedo, Nuvia M; Mulchandani, Ashok

    2016-01-01

    Carbon allotropes such as graphene and carbon nanotubes, have been incorporated in electrochemical biosensors for highly sensitive and selective detection of various analytes. The superior physical and electrical properties like high carrier mobility, ambipolar electric field effect, high surface area, flexibility and their compatibility with microfabrication techniques makes these carbon nanomaterials easy to integrate in field-effect transistor (FET)/chemiresistor type configuration which is suitable for portable and point-of-use/field-deployable sensors. This review covers the synthesis of carbon nanostructures (graphene and CNTs) and their integration into devices using various fabrication methods. Finally, we discuss the recent reports showing different sensing platforms that incorporate biomolecules like enzymes, antibodies and aptamers as recognition elements for fabrication of simple, low cost, compact biosensors that can be used for on-site, rapid environmental monitoring of environmental pollutants like pathogens, heavy metals, pesticides and explosives. PMID:25956023

  8. Protein-Based Graphene Biosensors: Optimizing Artificial Chemoreception in Bilayer Lipid Membranes

    Directory of Open Access Journals (Sweden)

    Christina G. Siontorou

    2016-09-01

    Full Text Available Proteinaceous moieties are critical elements in most detection systems, including biosensing platforms. Their potential is undoubtedly vast, yet many issues regarding their full exploitation remain unsolved. On the other hand, the biosensor formats with the higher marketability probabilities are enzyme in nature and electrochemical in concept. To no surprise, alternative materials for hosting catalysis within an electrode casing have received much attention lately to demonstrate a catalysis-coated device. Graphene and ZnO are presented as ideal materials to modify electrodes and biosensor platforms, especially in protein-based detection. Our group developed electrochemical sensors based on these nanomaterials for the sensitive detection of cholesterol using cholesterol oxidase incorporated in stabilized lipid films. A comparison between the two platforms is provided and discussed. In a broader sense, the not-so-remote prospect of quickly assembling a protein-based flexible biosensing detector to fulfill site-specific requirements is appealing to both university researchers and industry developers.

  9. Glucose biosensors based on a gold nanodendrite modified screen-printed electrode

    Science.gov (United States)

    Liu, Hsi-Chien; Tsai, Chung-Che; Wang, Gou-Jen

    2013-05-01

    In this study, an enzymatic glucose biosensor based on a three-dimensional gold nanodendrite (GND) modified screen-printed electrode was developed. The GNDs were electrochemically synthesized on the working electrode component of a commercially available screen-printed electrode using a solution acquired by dissolving bulk gold in aqua regia as the precursor. The 3D GND electrode greatly enhanced the effective sensing area of the biosensor, which improved the sensitivity of glucose detection. Actual glucose detections demonstrated that the fabricated devices could perform at a sensitivity of 46.76 μA mM-1 cm-2 with a linear detection range from 28 μM-8.4 mM and detection limit of 7 μM. A fast response time (˜3 s) was also observed. Moreover, only a 20 μl glucose oxidase is required for detection owing to the incorporation of the commercially available screen-printed electrode.

  10. Network single-walled carbon nanotube biosensors for fast and highly sensitive detection of proteins

    Energy Technology Data Exchange (ETDEWEB)

    Hu Pingan; Zhang Jia; Wen Zhenzhong [Research Centre for Micro/Nanotechnology, Harbin Institute of Technology, No. 2 YiKuang Street, Harbin 150080 (China); Zhang Can, E-mail: hupa@hit.edu.cn [Centre for Advanced Photonics and Electronics, University of Cambridge, Cambridge CB3 0FA (United Kingdom)

    2011-08-19

    Detection of proteins is powerfully assayed in the diagnosis of diseases. A strategy for the development of an ultrahigh sensitivity biosensor based on a network single-walled carbon nanotube (SWNT) field-effect transistor (FET) has been demonstrated. Metallic SWNTs (m-SWNTs) in the network nanotube FET were selectively removed or cut via a carefully controlled procedure of electrical break-down (BD), and left non-conducting m-SWNTs which magnified the Schottky barrier (SB) area. This nanotube FET exhibited ultrahigh sensitivity and fast response to biomolecules. The lowest detection limit of 0.5 pM was achieved by exploiting streptavidin (SA) or a biotin/SA pair as the research model, and BD-treated nanotube biosensors had a 2 x 10{sup 4}-fold lower minimum detectable concentration than the device without BD treatment. The response time is in the range of 0.3-3 min.

  11. Directed assembly of carbon nanotubes on soft substrates for use as a flexible biosensor array

    Science.gov (United States)

    Koh, Juntae; Yi, Mihye; Lee, Byung Yang; Kim, Tae Hyun; Lee, Joohyung; Jhon, Young Min; Hong, Seunghun

    2008-12-01

    We have developed a method to selectively assemble and align carbon nanotubes (CNTs) on soft substrates for use as flexible biosensors. In this strategy, a thin oxide layer was deposited on soft substrates via low temperature plasma enhanced chemical vapor deposition, and a linker-free assembly process was applied on the oxide surface where the assembly of carbon nanotubes was guided by methyl-terminated molecular patterns on the oxide surface. The electrical characterization of the fabricated CNT devices exhibited a typical p-type gating effect and 1/f noise behavior. The bare oxide regions near CNTs were functionalized with glutamate oxidase to fabricate selective biosensors to detect two forms of glutamate substances existing in different situations: L-glutamic acid, a neurotransmitting material, and monosodium glutamate, a food additive.

  12. Directed-Assembly of Carbon Nanotubes on Soft Substrates for Flexible Biosensor Array

    Science.gov (United States)

    Lee, Hyoung Woo; Koh, Juntae; Lee, Byung Yang; Kim, Tae Hyun; Lee, Joohyung; Hong, Seunghun; Yi, Mihye; Jhon, Young Min

    2009-03-01

    We developed a method to selectively assemble and align carbon nanotubes (CNTs) on soft substrates for flexible biosensors. In this strategy, thin oxide layer was deposited on soft substrates via low temperature plasma enhanced chemical vapor deposition, and linker-free assembly process was applied onto the oxide surface where the assembly of carbon nanotubes was guided by methyl-terminated molecular patterns on the oxide surface. The electrical characterization of the fabricated CNT devices exhibited typical p-type gating effect and 1/f noise behavior. The bare oxide regions near CNTs were functionalized with glutamate oxidase to fabricate selective biosensors to detect two forms of glutamate substances existing in different situations: L-glutamic acid, a neuro-transmitting material, and monosodium glutamate, a food additive.

  13. Development of semiconductor radiation sensors for portable alarm-dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y. K.; Moon, B. S.; Chung, C. E.; Hong, S. B.; Kim, J. Y.; Kim, J. B.; Han, S. H.; Lee, W. G. [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2001-01-01

    We studied Semiconductor Radiation Sensors for Portable Alarm-Dosimeter. We calculated response functions for gamma energy 0.021, 0.122, 0.662, 0.835, 1.2 MeV using EGS4 codes. When we measured at various distance from source to detector, the detection efficiency of Si semiconductor detector was better than that of GM tube. The linear absorption coefficients of steel and aluminum plate were measured. These experimental results of the response of detector for intensity of radiation field coincide to the theoretical expectation. The count value of Si detector was changed with changing thickness of steel as changing threshold voltage of discriminator, and the linear absorption coefficient increased with increasing threshold voltage. Radiation detection efficiency shows difference at each threshold voltage condition. This results coincided to the theoretical simulation. 33 refs., 27 figs., 8 tabs. (Author)

  14. False alarm recognition in hyperspectral gas plume identification

    Energy Technology Data Exchange (ETDEWEB)

    Conger, James L. (San Ramon, CA); Lawson, Janice K. (Tracy, CA); Aimonetti, William D. (Livermore, CA)

    2011-03-29

    According to one embodiment, a method for analyzing hyperspectral data includes collecting first hyperspectral data of a scene using a hyperspectral imager during a no-gas period and analyzing the first hyperspectral data using one or more gas plume detection logics. The gas plume detection logic is executed using a low detection threshold, and detects each occurrence of an observed hyperspectral signature. The method also includes generating a histogram for all occurrences of each observed hyperspectral signature which is detected using the gas plume detection logic, and determining a probability of false alarm (PFA) for all occurrences of each observed hyperspectral signature based on the histogram. Possibly at some other time, the method includes collecting second hyperspectral data, and analyzing the second hyperspectral data using the one or more gas plume detection logics and the PFA to determine if any gas is present. Other systems and methods are also included.

  15. Crying of a newborn child: alarm signal or protocommunication?

    Science.gov (United States)

    Clarici, A; Travan, L; Accardo, A; De Vonderweid, U; Bava, A

    2002-12-01

    The purpose of the study was to explore whether the new-born cry is a simple alarm signal or differentiated cries with different meanings. 12 digital audio taped recordings of 6 full-term healthy babies were analysed. Cries of 6 newborns in this preliminary study were recorded in a pain condition after a prick for the hematic check-up the third day after delivery and then while crying spontaneously in the cradle. The sounds were sampled at 44100 Hz with a 16-bit resolution and converted to the .wav format. All the analyses were performed with a software written in the MAT-LAB environment. The most important result was that these new-born children modulated the supralaryngeal tract considerably more in cries following the painful stimulus than in "spontaneous" ones, as would be expected by the hypothesis of crying as "protolanguage."

  16. A new fire alarm system for electrical installations

    CERN Document Server

    Pietersen, A H

    1978-01-01

    Fires in electrical installations are considered to develop in four phases - initiation, smouldering, flame formation and heat development. Cables are among the more sensitive components, with working temperatures around 50 degrees C and fire detection at 70 degrees C. Conventional alarms include smoke detectors. The new technique described uses microcapsules containing powder forming a gas of the Freon type after diffusion. A typical microcapsule loses 4% per year and has a natural life of 10 years. Fabrication methods are described. Detection is by gas concentration, with a sensitivity of 1 to 10 ppm, or by acoustic methods with microphones to pick up the sound of fractures. Pressure/temperature characteristics of various types of Freon mixtures commercially available are given in graphical form.

  17. Portable microsystem integrates multifunctional dielectrophoresis manipulations and a surface stress biosensor to detect red blood cells for hemolytic anemia.

    Science.gov (United States)

    Sang, Shengbo; Feng, Qiliang; Jian, Aoqun; Li, Huiming; Ji, Jianlong; Duan, Qianqian; Zhang, Wendong; Wang, Tao

    2016-01-01

    Hemolytic anemia intensity has been suggested as a vital factor for the growth of certain clinical complications of sickle cell disease. However, there is no effective and rapid diagnostic method. As a powerful platform for bio-particles testing, biosensors integrated with microfluidics offer great potential for a new generation of portable point of care systems. In this paper, we describe a novel portable microsystem consisting of a multifunctional dielectrophoresis manipulations (MDM) device and a surface stress biosensor to separate and detect red blood cells (RBCs) for diagnosis of hemolytic anemia. The peripheral circuit to power the interdigitated electrode array of the MDM device and the surface stress biosensor test platform were integrated into a portable signal system. The MDM includes a preparing region, a focusing region, and a sorting region. Simulation and experimental results show the RBCs trajectories when they are subjected to the positive DEP force, allowing the successful sorting of living/dead RBCs. Separated RBCs are then transported to the biosensor and the capacitance values resulting from the variation of surface stress were measured. The diagnosis of hemolytic anemia can be realized by detecting RBCs and the portable microsystem provides the assessment to the hemolytic anemia patient. PMID:27647457

  18. Soft real-time alarm messages for ATLAS TDAQ

    Science.gov (United States)

    Darlea, G.; Al Shabibi, A.; Martin, B.; Lehmann Miotto, G.

    2010-05-01

    The ATLAS TDAQ network consists of three separate Ethernet-based networks (Data, Control and Management) with over 2000 end-nodes. The TDAQ system has to be aware of the meaningful network failures and events in order for it to take effective recovery actions. The first stage of the process is implemented with Spectrum, a commercial network management tool. Spectrum detects and registers all network events, then it publishes the information via a CORBA programming interface. A gateway program (called NSG—Network Service Gateway) connects to Spectrum through CORBA and exposes to its clients a Java RMI interface. This interface implements a callback mechanism that allows the clients to subscribe for monitoring "interesting" parts of the network. The last stage of the TDAQ network monitoring tool is implemented in a module named DNC (DAQ to Network Connection), which filters the events that are to be reported to the TDAQ system: it subscribes to the gateway only for the machines that are currently active in the system and it forwards only the alarms that are considered important for the current TDAQ data taking session. The network information is then synthesized and presented in a human-readable format. These messages can be further processed either by the shifter who is in charge, the network expert or the Online Expert System. This article aims to describe the different mechanisms of the chain that transports the network events to the front-end user, as well as the constraints and rules that govern the filtering and the final format of the alarm messages.

  19. Soft real-time alarm messages for ATLAS TDAQ

    Energy Technology Data Exchange (ETDEWEB)

    Darlea, G., E-mail: georgiana.lavinia.darlea@cern.c [CERN, Geneva (Switzerland); Al Shabibi, A.; Martin, B.; Lehmann Miotto, G. [CERN, Geneva (Switzerland)

    2010-05-21

    The ATLAS TDAQ network consists of three separate Ethernet-based networks (Data, Control and Management) with over 2000 end-nodes. The TDAQ system has to be aware of the meaningful network failures and events in order for it to take effective recovery actions. The first stage of the process is implemented with Spectrum, a commercial network management tool. Spectrum detects and registers all network events, then it publishes the information via a CORBA programming interface. A gateway program (called NSG-Network Service Gateway) connects to Spectrum through CORBA and exposes to its clients a Java RMI interface. This interface implements a callback mechanism that allows the clients to subscribe for monitoring 'interesting' parts of the network. The last stage of the TDAQ network monitoring tool is implemented in a module named DNC (DAQ to Network Connection), which filters the events that are to be reported to the TDAQ system: it subscribes to the gateway only for the machines that are currently active in the system and it forwards only the alarms that are considered important for the current TDAQ data taking session. The network information is then synthesized and presented in a human-readable format. These messages can be further processed either by the shifter who is in charge, the network expert or the Online Expert System. This article aims to describe the different mechanisms of the chain that transports the network events to the front-end user, as well as the constraints and rules that govern the filtering and the final format of the alarm messages.

  20. Surface engineered biosensors for the early detection of cancer

    Science.gov (United States)

    Islam, Muhymin

    Cancer commences in the building block of human body which is cells and in most of the cases remains silent at early stage. Diseases are only expressed at molecular and cellular level at primary stages. Recognition of diseases at this micro and nano level might reduce the mortality rate of cancer significantly. This research work aimed to introduce novel electronic biosensors for for identification of cancer at cellular level. The dissertation study focuses on 1) Label-Free Isolation of Metastatic Tumor Cells Using Filter Based Microfluidic device; 2) Nanotextured Polymer Substrates for Enhanced Cancer Cell Isolation and Cell Growth; 3) Nanotextured Microfluidic Channel for Electrical Profiling and Detection of Tumor Cells from Blood; and 4) Single Biochip for the Detection of Tumor Cells by Electrical Profile and Surface Immobilized Aptamer. Standard silicon processing techniques were followed to fabricate all of the biosensors. Nantoextruing and surface functionalizon were also incorporated to elevate the efficiency of the devices. The first approach aimed to detect cancer cells from blood based on their mechanophysical properties. Cancer cells are larger than blood cells but highly elastic in nature. These cells can squeeze through small microchannels much smaller than their size. The cross sectional area of the microchannels was optimized to isolate tumor cells from blood. Nanotextured polymer substrates, a platform inspired from the natural basement membrane was used to enhance the isolation and growth of tumor cells. Micro reactive ion etching was performed to have better control on features of nantoxtured surfaces and did not require any template. Next, electrical measurement of ionic current was performed across single microchannel to detect tumor cells from blood. Later, nanotexturing enhanced the efficiency of the device by selectively altering the translocation profile of cancer cells. Eventually aptamer functionalized nanotextured polymer surface was

  1. 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

  2. Nanoscale bacteriophage biosensors beyond phage display.

    Science.gov (United States)

    Lee, Jong-Wook; Song, Jangwon; Hwang, Mintai P; Lee, Kwan Hyi

    2013-01-01

    Bacteriophages are traditionally used for the development of phage display technology. Recently, their nanosized dimensions and ease with which genetic modifications can be made to their structure and function have put them in the spotlight towards their use in a variety of biosensors. In particular, the expression of any protein or peptide on the extraluminal surface of bacteriophages is possible by genetically engineering the genome. In addition, the relatively short replication time of bacteriophages offers researchers the ability to generate mass quantities of any given bacteriophage-based biosensor. Coupled with the emergence of various biomarkers in the clinic as a means to determine pathophysiological states, the development of current and novel technologies for their detection and quantification is imperative. In this review, we categorize bacteriophages by their morphology into M13-based filamentous bacteriophages and T4- or T7-based icosahedral bacteriophages, and examine how such advantages are utilized across a variety of biosensors. In essence, we take a comprehensive approach towards recent trends in bacteriophage-based biosensor applications and discuss their outlook with regards to the field of biotechnology.

  3. Nanoscale bacteriophage biosensors beyond phage display

    Directory of Open Access Journals (Sweden)

    Lee JW

    2013-10-01

    Full Text Available Jong-Wook Lee,1 Jangwon Song,1,2 Mintai P Hwang,1 Kwan Hyi Lee1,2 1Center for Biomaterials, Biomedical Research Institute, Korea Institute of Science and Technology, Seoul, Korea; 2Department of Biomedical Engineering, University of Science and Technology, Seoul, Korea Abstract: Bacteriophages are traditionally used for the development of phage display technology. Recently, their nanosized dimensions and ease with which genetic modifications can be made to their structure and function have put them in the spotlight towards their use in a variety of biosensors. In particular, the expression of any protein or peptide on the extraluminal surface of bacteriophages is possible by genetically engineering the genome. In addition, the relatively short replication time of bacteriophages offers researchers the ability to generate mass quantities of any given bacteriophage-based biosensor. Coupled with the emergence of various biomarkers in the clinic as a means to determine pathophysiological states, the development of current and novel technologies for their detection and quantification is imperative. In this review, we categorize bacteriophages by their morphology into M13-based filamentous bacteriophages and T4- or T7-based icosahedral bacteriophages, and examine how such advantages are utilized across a variety of biosensors. In essence, we take a comprehensive approach towards recent trends in bacteriophage-based biosensor applications and discuss their outlook with regards to the field of biotechnology. Keywords: biosensing, M13 bacteriophage, T4 bacteriophage, bacterial detection, Escherichia coli, SPR sensor

  4. Biosensor con nanoparticulas metálicas

    OpenAIRE

    Pino González de la Higuera, Pablo del; Pelaz, Beatriz; Polo, Ester; Grazú Bonavia, Valeria; MARTÍNEZ DE LA FUENTE, Jesús; Parro-García, Víctor

    2012-01-01

    La presente invención se refiere a un biosensor donde la detección del analito se realiza de forma visual por el cambio de color en las zonas del soporte en que el analito esté presente producido por las nanopartículas al ser irradiadas con una fuente de luz externa

  5. 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...

  6. 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...

  7. 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...

  8. Continuous-flow multi-analyte biosensor cartridge with controllable linear response range.

    Science.gov (United States)

    Frey, Olivier; Talaei, Sara; van der Wal, Peter D; Koudelka-Hep, Milena; de Rooij, Nico F

    2010-09-01

    This article presents the design and fabrication of a microfluidic biosensor cartridge for the continuous and simultaneous measurement of biologically relevant analytes in a sample solution. The biosensor principle is based on the amperometric detection of hydrogen peroxide using enzyme-modified electrodes. The low-integrated and disposable cartridge is fabricated in PDMS and SU-8 by rapid prototyping. The device is designed in such a way that it addresses two major challenges of biosensors using microfluidics approaches. Firstly, the enzymatic membrane is deposited on top of the platinum electrodes via a microfluidic deposition channel from outside the cartridge. This decouples the membrane deposition from the cartridge fabrication and enables the user to decide when and with what mixture he wants to modify the electrode. Secondly, by using laminar sheath-flow of the sample and a buffer solution, a dynamic diffusion layer is created. The analyte has to diffuse through the buffer solution layer before it can reach the immobilized enzyme membrane on the electrode. Controlling of the thickness of the diffusion layer by variation of the flow-rate of the two layers enables the user to adjust the sensitivity and the linear region of the sensor. The point where the buffer and sample stream join proved critical in creating the laminar sheath-flow. Results of computational simulations considering fluid dynamics and diffusion are presented. The consistency of the device was investigated through detection of glucose and lactate and are in accordance with the CFD simulations. A sensitivity of 157+/-28 nA/mM for the glucose sensor and 79+/-12 nA/mM for the lactate sensor was obtained. The linear response range of these biosensors could be increased from initially 2 mM up to 15 mM with a limit of detection of 0.2 mM.

  9. Detection of hydrogen peroxide in Photosystem II (PSII using catalytic amperometric biosensor

    Directory of Open Access Journals (Sweden)

    Ankush ePrasad

    2015-10-01

    Full Text Available Hydrogen peroxide (H2O2 is known to be generated in Photosystem II (PSII via enzymatic and non-enzymatic pathways. Hydrogen peroxide (H2O2 is known to be generated in Photosystem II (PSII via enzymatic and non-enzymatic pathways. Detection of H2O2 by different spectroscopic techniques has been explored, however its sensitive detection has always been a challenge in photosynthetic research. During the recent past, fluorescence probes such as Amplex Red has been used but is known to either lack specificity or limitation with respect to the minimum detection limit of H2O2. We have employed an electrochemical biosensor for real time monitoring of H2O2 generation at the level of sub-cellular organelles. The electrochemical biosensor comprises of counter electrode and working electrodes. The counter electrode is a platinum plate, while the working electrode is a mediator based catalytic amperometric biosensor device developed by the coating of a carbon electrode with osmium-horseradish peroxidase which acts as H2O2 detection sensor. In the current study, generation and kinetic behaviour of H2O2 in PSII membranes have been studied under light illumination. Electrochemical detection of H2O2 using the catalytic amperometric biosensor device is claimed to serve as a promising technique for detection of H2O2 in photosynthetic cells and subcellular structures including PSII or thylakoid membranes. It can also provide a precise information on qualitative determination of H2O2 and thus can be widely used in photosynthetic research.

  10. Desarrollo de un Biosensor Amperométrico en Configuración plana para la Cuantificación de Colesterol Development of an Amperometric Biosensor in Planar Configuration for the Quantification of Cholesterol

    Directory of Open Access Journals (Sweden)

    Mónica Hernández

    2011-01-01

    Full Text Available Se presenta el desarrollo de un biosensor amperométrico de colesterol en configuración plana, el cual es fabricado mediante procesos serigráficos compatibles con metodologías de producción automatizadas. El dispositivo incorpora tetracianoquinodimetano, TCNQ, como mediador a fin de reducir el potencial de trabajo y minimizar las interferencias. Presenta un intervalo de respuesta lineal de 2- 12 mM con un límite de detección de 1.56 mM , requiriendo un volumen de muestra de solo 7.2 μ L. Sus características lo hacen adecuado para el análisis descentralizado de colesterol en suero sanguíneo y alimentos. La propuesta muestra que sin grandes recursos técnicos ni económicos es posible desarrollar biosensores con características de respuesta competitivas y compatibles con la producción en masa.The development of a cholesterol amperometric biosensor in planar configuration is presented. The device is constructed by screen printing processes that are compatible with automated production methods. The electrochemical transducer incorporates tetracyanoquinodimethane, TCNQ, as mediator in order to reduce the work potential and minimize interferences. The biosensor presents an interval of lineal answer of 2- 12 mM with a limit of detection of 1.56 mM , requiring a volume of sample of only 7.2 µL. Its characteristics make it adequate for the analysis of cholesterol in blood serum and foods. The designed cholesterol amperometric biosensor demonstrates that without major technical or economic resources it is possible to develop biosensors with response characteristics competitive and compatible with mass production.

  11. Recent Advances in Biosensor Technology for Potential Applications - An Overview.

    Science.gov (United States)

    Vigneshvar, S; Sudhakumari, C C; Senthilkumaran, Balasubramanian; Prakash, Hridayesh

    2016-01-01

    Imperative utilization of biosensors has acquired paramount importance in the field of drug discovery, biomedicine, food safety standards, defense, security, and environmental monitoring. This has led to the invention of precise and powerful analytical tools using biological sensing element as biosensor. Glucometers utilizing the strategy of electrochemical detection of oxygen or hydrogen peroxide using immobilized glucose oxidase electrode seeded the discovery of biosensors. Recent advances in biological techniques and instrumentation involving fluorescence tag to nanomaterials have increased the sensitive limit of biosensors. Use of aptamers or nucleotides, affibodies, peptide arrays, and molecule imprinted polymers provide tools to develop innovative biosensors over classical methods. Integrated approaches provided a better perspective for developing specific and sensitive biosensors with high regenerative potentials. Various biosensors ranging from nanomaterials, polymers to microbes have wider potential applications. It is quite important to integrate multifaceted approaches to design biosensors that have the potential for diverse usage. In light of this, this review provides an overview of different types of biosensors being used ranging from electrochemical, fluorescence tagged, nanomaterials, silica or quartz, and microbes for various biomedical and environmental applications with future outlook of biosensor technology. PMID:26909346

  12. Recent Advances in Biosensor Technology for Potential Applications - An Overview.

    Science.gov (United States)

    Vigneshvar, S; Sudhakumari, C C; Senthilkumaran, Balasubramanian; Prakash, Hridayesh

    2016-01-01

    Imperative utilization of biosensors has acquired paramount importance in the field of drug discovery, biomedicine, food safety standards, defense, security, and environmental monitoring. This has led to the invention of precise and powerful analytical tools using biological sensing element as biosensor. Glucometers utilizing the strategy of electrochemical detection of oxygen or hydrogen peroxide using immobilized glucose oxidase electrode seeded the discovery of biosensors. Recent advances in biological techniques and instrumentation involving fluorescence tag to nanomaterials have increased the sensitive limit of biosensors. Use of aptamers or nucleotides, affibodies, peptide arrays, and molecule imprinted polymers provide tools to develop innovative biosensors over classical methods. Integrated approaches provided a better perspective for developing specific and sensitive biosensors with high regenerative potentials. Various biosensors ranging from nanomaterials, polymers to microbes have wider potential applications. It is quite important to integrate multifaceted approaches to design biosensors that have the potential for diverse usage. In light of this, this review provides an overview of different types of biosensors being used ranging from electrochemical, fluorescence tagged, nanomaterials, silica or quartz, and microbes for various biomedical and environmental applications with future outlook of biosensor technology.

  13. Recent advances in biosensor technology for potential applications - An overview

    Directory of Open Access Journals (Sweden)

    vigneshvar es

    2016-02-01

    Full Text Available Imperative utilization of biosensors has acquired paramount importance in the field of drug discovery, biomedicine, food safety standards, defence, security and environmental monitoring. This has led to the invention of precise and powerful analytical tools using biological sensing element as biosensor. Glucometers utilizing the strategy of electrochemical detection of oxygen or hydrogen peroxide using immobilized glucose oxidase electrode seeded the discovery of biosensors. Recent advances in biological techniques and instrumentation involving fluorescence tag to nanomaterials have increased the sensitive limit of biosensors. Use of aptamers or nucleotides, affibodies, peptide arrays and molecule imprinted polymers provide tools to develop innovative biosensors over classical methods. Integrated approaches provided a better perspective for developing specific and sensitive biosensors with high regenerative potentials. Variety of biosensors ranging from nanomaterials, polymers to microbes have wider potential applications. It is quite important to integrate multifaceted approaches to design biosensors that have the potential for diverse usage. In light of this, this review provides an overview of different types of biosensors being used ranging from electrochemical, fluorescence tagged, nanomaterials, silica or quartz and microbes for various biomedical and environmental applications with future outlook of biosensor technology.

  14. Conformational design optimization of transcription factor beacon DNA biosensors

    Directory of Open Access Journals (Sweden)

    Stephen R. Schaffner

    2014-12-01

    Full Text Available Widespread application of promising DNA-based transcription factor protein (TF biosensors is limited by our ability to control their binding properties. Because the binding properties of this class of biosensors are affected by how well the biosensor switches between binding and non-binding conformations, we investigated the effects of varying conformational stability on the ability of biosensors to detect the oncologically-relevant Myc/Max TF dimer complex. To do this, we employed a custom algorithm that designed and evaluated possible biosensors based on the Myc/Max TF recognition sequence, choosing algorithmic parameters that selected for biosensors with varied conformational stability due to changes in stem length. Biosensors with recognition stem lengths of 8 base pairs (bp, 12 bp, or 21 bp were selected and synthesized. Biosensor binding affinity changes and kinetic association rates were found to be significantly affected by changes in conformational stability (with binding affinity increasing with stem length, from 80 ± 20 nM to 440 ± 80 nM, and kinetic switching rate being tenfold impacted in the longer biosensors. These results show that increased stability can have significant inverse effects on overall biosensor performance, providing important implications for effective biosensor designs. We applied these design insights to generate a biosensor that tested and confirmed a predicted in vivo interaction between two TFs (ATF3 and Max, illustrating the potential for rationally-designed, TF-detecting biosensors as a routine analytical tool.

  15. Applications of the Petri net to simulate, test, and validate the performance and safety of complex, heterogeneous, multi-modality patient monitoring alarm systems.

    Science.gov (United States)

    Sloane, E B; Gelhot, V

    2004-01-01

    This research is motivated by the rapid pace of medical device and information system integration. Although the ability to interconnect many medical devices and information systems may help improve patient care, there is no way to detect if incompatibilities between one or more devices might cause critical events such as patient alarms to go unnoticed or cause one or more of the devices to become stuck in a disabled state. Petri net tools allow automated testing of all possible states and transitions between devices and/or systems to detect potential failure modes in advance. This paper describes an early research project to use Petri nets to simulate and validate a multi-modality central patient monitoring system. A free Petri net tool, HPSim, is used to simulate two wireless patient monitoring networks: one with 44 heart monitors and a central monitoring system and a second version that includes an additional 44 wireless pulse oximeters. In the latter Petri net simulation, a potentially dangerous heart arrhythmia and pulse oximetry alarms were detected. PMID:17271039

  16. Nanomaterial-based biosensors for food toxin detection.

    Science.gov (United States)

    Malhotra, Bansi D; Srivastava, Saurabh; Ali, Md Azahar; Singh, Chandan

    2014-10-01

    There is an increased interest toward the development of bioelectronic devices for food toxin (mycotoxins) detection. Mycotoxins are highly toxic secondary metabolites produced by fungi like Fusarium, Aspergillus, and Penicillium that are frequently found in crops or during storage of food including cereals, nuts, fruits, etc. The contamination of food by mycotoxins has become a matter of increasing concern. High levels of mycotoxins in the diet can cause adverse, acute, and chronic effects on human health and a variety of animal species. Side effects may particularly affect the liver, kidney, nervous system, endocrine system, and immune system. Among 300 mycotoxins known till date, there are a few that are considered to play an important part in food safety, and for these, a range of analytical methods have been developed. Some of the important mycotoxins include aflatoxins, ochratoxins, fumonisins, citreoviridin, patulin, citrinin, and zearalenon. The conventional methods of analysis of mycotoxins normally require sophisticated instrumentation, e.g., liquid chromatography with fluorescence or mass detectors, combined with extraction procedures for sample preparation. Hence, new analysis tools are necessary to attain more sensitive, specific, rapid, and reliable information about the desired toxin. For the last about two decades, the research and development of simpler and faster analytical procedures based on affinity biosensors has aroused much interest due to their simplicity and sensitivity. The nanomaterials have recently had a great impact on the development of biosensors. The functionalized nanomaterials are used as catalytic tools, immobilization platforms, or as optical or electroactive labels to improve the biosensing performance to obtain higher sensitivity, stability, and selectivity. Nanomaterials, such as carbon nanomaterials (carbon nanotubes and graphene), metal nanoparticles, nanowires, nanocomposites, and nanostructured metal oxide nanoparticles

  17. Nanoelectrode and nanoparticle based biosensors for environmental and health monitoring

    Science.gov (United States)

    Syed, Lateef Uddin

    Reduction in electrode size down to nanometers dramatically enhances the detection sensitivity and temporal resolution. Here we explore nanoelectrode arrays (NEAs) and nanoparticles in building high performance biosensors. Vertically aligned carbon nanofibers (VACNFs) of diameter ˜100 nm were grown on a Si substrate using plasma enhanced chemical vapor deposition. SiO2 embedded CNF NEAs were then fabricated using techniques like chemical vapor deposition, mechanical polishing, and reactive ion etching, with CNF tips exposed at the final step. The effect of the interior structure of CNFs on electron transfer rate (ETR) was investigated by covalently attaching ferrocene molecules to the exposed end of CNFs. Anomalous differences in the ETR were observed between DC voltammetry (DCV) and AC voltammetry (ACV). The findings from this study are currently being extended to develop an electrochemical biosensor for the detection of cancerous protease (legumain). Preliminary results with standard macro glassy carbon electrodes show a significant decrease in ACV signal, which is encouraging. In another study, NEA was employed to capture and detect pathogenic bacteria using AC dielectrophoresis (DEP) and electrochemical impedance spectroscopy (EIS). A nano-DEP device was fabricated using photolithography processes to define a micro patterned exposed active region on NEA and a microfluidic channel on macro-indium tin oxide electrode. Enhanced electric field gradient at the exposed CNF tips was achieved due to the nanometer size of the electrodes, because of which each individual exposed tip can act as a potential DEP trap to capture the pathogen. Significant decrease in the absolute impedance at the NEA was also observed by EIS experiments. In a final study, we modified gold nanoparticles (GNPs) with luminol to develop chemiluminescence (CL) based blood biosensor. Modified GNPs were characterized by UV-Vis, IR spectroscopy and TEM. We have applied this CL method for the

  18. 76 FR 76327 - Installation of Radiation Alarms for Rooms Housing Neutron Sources

    Science.gov (United States)

    2011-12-07

    ... COMMISSION 10 CFR Part 73 Installation of Radiation Alarms for Rooms Housing Neutron Sources AGENCY: Nuclear... radiation alarms in rooms housing neutron sources. DATES: Submit comments by February 21, 2012. Comments..., Radiation Safety for Research. Mr. Hamawy is concerned about the security of neutron sources. III....

  19. A Computational Pipeline to Improve Clinical Alarms Using a Parallel Computing Infrastructure

    Science.gov (United States)

    Nguyen, Andrew V.

    2013-01-01

    Physicians, nurses, and other clinical staff rely on alarms from various bedside monitors and sensors to alert when there is a change in the patient's clinical status, typically when urgent intervention is necessary. These alarms are usually embedded directly within the sensor or monitor and lacks the context of the patient's medical history and…

  20. New alarm system approach for detection and location of small leaks from pipelines

    International Nuclear Information System (INIS)

    Vapor Monitoring Wells are an accepted method to monitor for leaks from underground storage tanks and pipe. This paper discusses a method that is similar to well leak detection technique, yet superior for pipelines for reasons to be defined. Vapors from a leak source migrate through the soil. The time required for a leak to migrate a known distance is dependent on the vapor pressure of the leaking substance, the leak rate, and finally, soil type, compaction, and collection device is to the leak source the shorter the time required for the premise that the sensor tube acts as a continuous row of wells that can all be automatically sampled with one central pump/detector. The system precisely locates the leak. The benefit of this system is earlier detection and location of small leaks to minimize product loss to the environment. Dr. Wolfgang Issel developed Leak Alarm System for Pollutants, LASP, with the support of the German Ministry of Research and Technology to protect groundwater and other environmentally sensitive zones

  1. Analytical Problems in Exposing Amperometric Enzyme Biosensors to Biological Fluids

    Directory of Open Access Journals (Sweden)

    Gaia Rocchitta

    2016-05-01

    Full Text Available Enzyme-based chemical biosensors are based on biological recognition. In order to operate, the enzymes must be available to catalyze a specific biochemical reaction and be stable under the normal operating conditions of the biosensor. Design of biosensors is based on knowledge about the target analyte, as well as the complexity of the matrix in which the analyte has to be quantified. This article reviews the problems resulting from the interaction of enzyme-based amperometric biosensors with complex biological matrices containing the target analyte(s. One of the most challenging disadvantages of amperometric enzyme-based biosensor detection is signal reduction from fouling agents and interference from chemicals present in the sample matrix. This article, therefore, investigates the principles of functioning of enzymatic biosensors, their analytical performance over time and the strategies used to optimize their performance. Moreover, the composition of biological fluids as a function of their interaction with biosensing will be presented.

  2. Modelling Amperometric Biosensors Based on Chemically Modified Electrodes

    Science.gov (United States)

    Baronas, Romas; Kulys, Juozas

    2008-01-01

    The response of an amperometric biosensor based on a chemically modified electrode was modelled numerically. A mathematical model of the biosensor is based on a system of non-linear reaction-diffusion equations. The modelling biosensor comprises two compartments: an enzyme layer and an outer diffusion layer. In order to define the main governing parameters the corresponding dimensionless mathematical model was derived. The digital simulation was carried out using the finite difference technique. The adequacy of the model was evaluated using analytical solutions known for very specific cases of the model parameters. By changing model parameters the output results were numerically analyzed at transition and steady state conditions. The influence of the substrate and mediator concentrations as well as of the thicknesses of the enzyme and diffusion layers on the biosensor response was investigated. Calculations showed complex kinetics of the biosensor response, especially when the biosensor acts under a mixed limitation of the diffusion and the enzyme interaction with the substrate.

  3. Multifunctional substrates of thin porous alumina for cell biosensors

    KAUST Repository

    Toccafondi, Chiara

    2014-02-27

    We have fabricated anodic porous alumina from thin films (100/500 nm) of aluminium deposited on technological substrates of silicon/glass, and investigated the feasibility of this material as a surface for the development of analytical biosensors aiming to assess the status of living cells. To this goal, porous alumina surfaces with fixed pitch and variable pore size were analyzed for various functionalities. Gold coated (about 25 nm) alumina revealed surface enhanced Raman scattering increasing with the decrease in wall thickness, with factor up to values of approximately 104 with respect to the flat gold surface. Bare porous alumina was employed for micro-patterning and observation via fluorescence images of dye molecules, which demonstrated the surface capability for a drug-loading device. NIH-3T3 fibroblast cells were cultured in vitro and examined after 2 days since seeding, and no significant (P > 0.05) differences in their proliferation were observed on porous and non-porous materials. The effect on cell cultures of pore size in the range of 50–130 nm—with pore pitch of about 250 nm—showed no significant differences in cell viability and similar levels in all cases as on a control substrate. Future work will address combination of all above capabilities into a single device.

  4. Super-Sensitive and Robust Biosensors from Supported Polymer Bilayers

    Energy Technology Data Exchange (ETDEWEB)

    Paxton, Walter F. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-09-01

    Biological organisms are potentially the most sensitive and selective biological detection systems known, yet we are currently severely limited in our ability to exploit biological interactions in sensory devices, due in part to the limited stability of biological systems and derived materials. This proposal addresses an important aspect of integrating biological sensory materials in a solid state device. If successful, such technology could enable entirely new classes of robust biosensors that could be miniaturized and deployed in the field. The critical aims of the proposed work were 1) the calibration of a more versatile approach to measuring pH, 2) the use of this method to monitor pH changes caused by the light-induced pumping of protons across vesicles with bacteriorhodopsin integrated into the membranes (either polymer or lipid); 3) the preparation of bilayer assemblies on platinum surfaces; 4) the enhanced detection of lightinduced pH changes driven by bR-loaded supported bilayers. I have developed a methodology that may enable that at interfaces and developed a methodology to characterize the functionality of bilayer membranes with reconstituted membrane proteins. The integrity of the supported bilayer films however must be optimized prior to the full realization of the work originally envisioned in the original proposal. Nevertheless, the work performed on this project and the encouraging results it has produced has demonstrated that these goals are challenging yet within reach.

  5. Biosensor development for the analysis of food quality.

    OpenAIRE

    Giakoumaki, Elsa

    2003-01-01

    This thesis describes the development and evaluation of a number of biosensors for food applications. The first part of this thesis deals with the development of Surface Plasmon Resonance (SPR) biosensor systems, coupled with Polymerase Chain Reaction (PCR) for the detection of GMO related amplified nucleic acids in foodstuffs. The first SPR Biosensor described, used streptavidin-biotin linkage chemistry to attach a P35S nucleic acid probe on dextran-coa...

  6. Recent advances in biosensor technology for potential applications - An overview

    OpenAIRE

    vigneshvar es; sudhakumari ecc; Balasubramanian eSENTHILKUMARAN; Hridayesh ePrakash

    2016-01-01

    Imperative utilization of biosensors has acquired paramount importance in the field of drug discovery, biomedicine, food safety standards, defence, security and environmental monitoring. This has led to the invention of precise and powerful analytical tools using biological sensing element as biosensor. Glucometers utilizing the strategy of electrochemical detection of oxygen or hydrogen peroxide using immobilized glucose oxidase electrode seeded the discovery of biosensors. Recent advances i...

  7. Recent Advances in Application of Biosensors in Tissue Engineering

    OpenAIRE

    Anwarul Hasan; Md Nurunnabi; Mahboob Morshed; Arghya Paul; Alessandro Polini; Tapas Kuila; Moustafa Al Hariri; Yong-kyu Lee; Jaffa, Ayad A.

    2014-01-01

    Biosensors research is a fast growing field in which tens of thousands of papers have been published over the years, and the industry is now worth billions of dollars. The biosensor products have found their applications in numerous industries including food and beverages, agricultural, environmental, medical diagnostics, and pharmaceutical industries and many more. Even though numerous biosensors have been developed for detection of proteins, peptides, enzymes, and numerous other biomolecule...

  8. Optimization of Xenon Biosensors for Detection of Protein Interactions

    OpenAIRE

    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.

    2005-01-01

    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, che...

  9. High-resolution biosensor based on localized surface plasmons

    OpenAIRE

    Piliarik, M.; Šípová, H. (Hana); Kvasnička, P.; Galler, N.; Krenn, J. R.; Homola, J. (Jiří)

    2012-01-01

    We report on a new biosensor with localized surface plasmons (LSP) based on an array of gold nanorods and TIR imaging in polarization contrast. The sensitivity of the new biosensor is characterized and a model detection of DNA hybridization is carried out and results compared with a conventional SPR biosensor, showing the same performance while involving significantly lower surface densities of interacting molecules. Limit of detection was 100 pM and a surface density resolution only 35 fg×mm2.

  10. In Vitro Evaluation of Fluorescence Glucose Biosensor Response

    OpenAIRE

    Mamdouh Aloraefy; T. Joshua Pfefer; 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...

  11. Emerging Synergy between Nanotechnology and Implantable Biosensors: A Review

    OpenAIRE

    Vaddiraju, SanthiSagar; Tomazos, Ioannis; Burgess, Diane J.; Jain, Faquir C.; Papadimitrakopoulos, Fotios

    2009-01-01

    The development of implantable biosensors for continuous monitoring of metabolites is an area of sustained scientific and technological interest. On the other hand, nanotechnology, a discipline which deals with the properties of materials at the nanoscale, is developing as a potent tool to enhance the performance of these biosensors. This article reviews the current state of implantable biosensors, highlighting the synergy between nanotechnology and sensor performance. Emphasis is placed on t...

  12. Compositions, devices and methods for SERS and LSPR

    Energy Technology Data Exchange (ETDEWEB)

    Van Duyne, Richard P; Zhang, Xiaoyu; Zhao, Jing; Whitney, Alyson V; Elam, Jeffrey W; Schatz, George C; Stair, Peter C; Zou, Shengli; Young, Matthew; Lyandres, Olga

    2014-01-14

    The present invention relates to compositions, devices and methods for detecting microorganisms (e.g., anthrax). In particular, the present invention provides portable, surface-enhanced Raman biosensors, and associated substrates, and methods of using the same, for use in rapidly detecting and identifying microorganisms (e.g., anthrax).

  13. Nanotechnology Based Materials and Devices for Health Care

    Science.gov (United States)

    Srivastava, Deepaka; Cho, K.; Brenner, Don; Menon, Madhu; Andriotis, Antonis; Sagman, Uri; Biegel, Bryan A. (Technical Monitor)

    2002-01-01

    This viewgraph presentation provides information on trends in NASA nanotechnology research and development, and future biotechnological applications for that nanotechnology. The presentation covers nanoelectronics, nanosensors, and nanomaterials, biomimetics, devices and materials for health care, carbon nanotubes, biosensors for astrobiology, solid-state nanopores for DNA sequencing, and protein nanotubes.

  14. Novel concepts on pregnancy clocks and alarms: redundancy and synergy in human parturition.

    Science.gov (United States)

    Menon, Ramkumar; Bonney, Elizabeth A; Condon, Jennifer; Mesiano, Sam; Taylor, Robert N

    2016-09-01

    The signals and mechanisms that synchronize the timing of human parturition remain a mystery and a better understanding of these processes is essential to avert adverse pregnancy outcomes. Although our insights into human labor initiation have been informed by studies in animal models, the timing of parturition relative to fetal maturation varies among viviparous species, indicative of phylogenetically different clocks and alarms; but what is clear is that important common pathways must converge to control the birth process. For example, in all species, parturition involves the transition of the myometrium from a relaxed to a highly excitable state, where the muscle rhythmically and forcefully contracts, softening the cervical extracellular matrix to allow distensibility and dilatation and thus a shearing of the fetal membranes to facilitate their rupture. We review a number of theories promulgated to explain how a variety of different timing mechanisms, including fetal membrane cell senescence, circadian endocrine clocks, and inflammatory and mechanical factors, are coordinated as initiators and effectors of parturition. Many of these factors have been independently described with a focus on specific tissue compartments.In this review, we put forth the core hypothesis that fetal membrane (amnion and chorion) senescence is the initiator of a coordinated, redundant signal cascade leading to parturition. Whether modified by oxidative stress or other factors, this process constitutes a counting device, i.e. a clock, that measures maturation of the fetal organ systems and the production of hormones and other soluble mediators (including alarmins) and that promotes inflammation and orchestrates an immune cascade to propagate signals across different uterine compartments. This mechanism in turn sensitizes decidual responsiveness and eventually promotes functional progesterone withdrawal in the myometrium, leading to increased myometrial cell contraction and the

  15. Development of Digital Boron Dilution Alarm System (DBDAS)

    International Nuclear Information System (INIS)

    It is imperative that a reactor which has been shutdown remain subcritical and not inadvertently return to power. Such an event could occur for instance through failure of a component in the complex control system or inadvertent action taken by the operator. In any case, during such an event the reactor approaches criticality exponentially with respect to time thus making it more difficult for the operator to detect the event and take appropriate action before the reactor goes to criticality [Ref. 1]. This paper is prepared for the development of the Digital Boron Dilution Alarm System (DBDAS) to improve the sub-criticality monitoring of Advanced Power Reactor 1400 Standard Nuclear Power Plant (APR1400). This system is designed to provide operators with useful information about an inadvertent boron dilution event occurring with the plant in Modes 3, 4, 5, and 6 before the reactor coolant system is diluted sufficiently to result in a total loss of shutdown margin. The acceptance criteria of APR1400 for an unplanned boron (moderator) dilution specify at least 30 minutes in all operational modes. The main features of DBAS are the use of digital information from the startup neutron monitoring channels and a boronometer

  16. Development of Digital Boron Dilution Alarm System (DBDAS)

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Ho Cheol; Lee, Hwan Soo; Moon, Chan Kook [Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

    2012-05-15

    It is imperative that a reactor which has been shutdown remain subcritical and not inadvertently return to power. Such an event could occur for instance through failure of a component in the complex control system or inadvertent action taken by the operator. In any case, during such an event the reactor approaches criticality exponentially with respect to time thus making it more difficult for the operator to detect the event and take appropriate action before the reactor goes to criticality [Ref. 1]. This paper is prepared for the development of the Digital Boron Dilution Alarm System (DBDAS) to improve the sub-criticality monitoring of Advanced Power Reactor 1400 Standard Nuclear Power Plant (APR1400). This system is designed to provide operators with useful information about an inadvertent boron dilution event occurring with the plant in Modes 3, 4, 5, and 6 before the reactor coolant system is diluted sufficiently to result in a total loss of shutdown margin. The acceptance criteria of APR1400 for an unplanned boron (moderator) dilution specify at least 30 minutes in all operational modes. The main features of DBAS are the use of digital information from the startup neutron monitoring channels and a boronometer

  17. Early warnings and missed alarms for abrupt monsoon transitions

    Directory of Open Access Journals (Sweden)

    Z. A. Thomas

    2015-04-01

    Full Text Available Palaeo-records from China (Cheng et al., 2009; Wang et al., 2008, 2001 demonstrate the East Asian Summer Monsoon (EASM is dominated by abrupt and large magnitude monsoon shifts on millennial timescales, switching between periods of high and weak monsoon rains. It has been hypothesised that over these timescales, the EASM exhibits two stable states with bifurcation-type tipping points between them (Schewe et al., 2012. Here we test this hypothesis by looking for early warning signals of past bifurcations in speleothem records from Sanbao Cave and Hulu Cave, China (Wang et al., 2008, 2001, spanning the penultimate glacial cycle, and in multiple model simulations derived from the data. We find hysteresis behaviour in our model simulations with transitions directly forced by solar insolation. We detect critical slowing down prior to an abrupt monsoon shift during the penultimate deglaciation consistent with long-term orbital forcing. However, such signals are only detectable when the change in system stability is sufficiently slow to be detected by the sampling resolution of the dataset, raising the possibility that the alarm was missed and a similar forcing drove earlier EASM shifts.

  18. Early warnings and missed alarms for abrupt monsoon transitions

    Science.gov (United States)

    Thomas, Z. A.; Kwasniok, F.; Boulton, C. A.; Cox, P. M.; Jones, R. T.; Lenton, T. M.; Turney, C. S. M.

    2015-12-01

    Palaeo-records from China demonstrate that the East Asian Summer Monsoon (EASM) is dominated by abrupt and large magnitude monsoon shifts on millennial timescales, switching between periods of high and weak monsoon rains. It has been hypothesized that over these timescales, the EASM exhibits two stable states with bifurcation-type tipping points between them. Here we test this hypothesis by looking for early warning signals of past bifurcations in speleothem δ18O records from Sanbao Cave and Hulu Cave, China, spanning the penultimate glacial cycle. We find that although there are increases in both autocorrelation and variance preceding some of the monsoon transitions during this period, it is only immediately prior to the abrupt monsoon shift at the penultimate deglaciation (Termination II) that statistically significant increases are detected. To supplement our data analysis, we produce and analyse multiple model simulations that we derive from these data. We find hysteresis behaviour in our model simulations with transitions directly forced by solar insolation. However, signals of critical slowing down, which occur on the approach to a bifurcation, are only detectable in the model simulations when the change in system stability is sufficiently slow to be detected by the sampling resolution of the data set. This raises the possibility that the early warning "alarms" were missed in the speleothem data over the period 224-150 kyr and it was only at the monsoon termination that the change in the system stability was sufficiently slow to detect early warning signals.

  19. Amperometric Biosensors for Real Time Assays of Organophosphates

    Directory of Open Access Journals (Sweden)

    Kamil Kuca

    2008-09-01

    Full Text Available An amperometric biosensor based on acetylcholinesterase (AChE immobilized in gelatin was used to develop an assay for the organophosphate paraoxon. The more traditional manner employing preincubation was used for comparison between measurement procedures, although the aim of the study was to examine the performance of the biosensor for real time monitoring of organophosphates. The biosensor was immersed in a reaction chamber and paraoxon was injected inside. We were able to detect 200 pg of paraoxon within one minute or 2.5 ppb when the biosensor was preincubed in the sample solution for 15 minutes. The practical impact and expectations are discussed.

  20. A Highly Responsive Silicon Nanowire/Amplifier MOSFET Hybrid Biosensor

    OpenAIRE

    Jieun Lee; Jaeman Jang; Bongsik Choi; Jinsu Yoon; Jee-Yeon Kim; Yang-Kyu Choi; Dong Myong Kim; Dae Hwan Kim; Sung-Jin Choi

    2015-01-01

    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 advantage of high density and low noise performance. The biosensor shows a current response of 5.74 decades per pH for pH detection, which is 2.5 × 105 times larger than that of a single SiNW sensor. I...

  1. Engineering an NADPH/NADP+ Redox Biosensor in Yeast

    DEFF Research Database (Denmark)

    Zhang, Jie; Sonnenschein, Nikolaus; Pihl, Thomas Peter Boye;

    2016-01-01

    Genetically encoded biosensors have emerged as powerful tools for timely and precise in vivo evaluation of cellular metabolism. In particular, biosensors that can couple intercellular cues with downstream signaling responses are currently attracting major attention within health science and biote......Genetically encoded biosensors have emerged as powerful tools for timely and precise in vivo evaluation of cellular metabolism. In particular, biosensors that can couple intercellular cues with downstream signaling responses are currently attracting major attention within health science...... and biotechnology. Still, there is a need for bioprospecting and engineering of more biosensors to enable real-time monitoring of specific cellular states and controlling downstream actuation. In this study, we report the engineering and application of a transcription factor-based NADPH/NADP+ redox biosensor...... in the budding yeast Saccharomyces cerevisiae. Using the biosensor, we are able to monitor the cause of oxidative stress by chemical induction, and changes in NADPH/NADP+ ratios caused by genetic manipulations. Because of the regulatory potential of the biosensor, we also show that the biosensor can actuate upon...

  2. Surface Generated Acoustic Wave Biosensors for the Detection of Pathogens: A Review

    Directory of Open Access Journals (Sweden)

    Antonio Arnau-Vives

    2009-07-01

    Full Text Available This review presents a deep insight into the Surface Generated Acoustic Wave (SGAW technology for biosensing applications, based on more than 40 years of technological and scientific developments. In the last 20 years, SGAWs have been attracting the attention of the biochemical scientific community, due to the fact that some of these devices - Shear Horizontal Surface Acoustic Wave (SH-SAW, Surface Transverse Wave (STW, Love Wave (LW, Flexural Plate Wave (FPW, Shear Horizontal Acoustic Plate Mode (SH-APM and Layered Guided Acoustic Plate Mode (LG-APM - have demonstrated a high sensitivity in the detection of biorelevant molecules in liquid media. In addition, complementary efforts to improve the sensing films have been done during these years. All these developments have been made with the aim of achieving, in a future, a highly sensitive, low cost, small size, multi-channel, portable, reliable and commercially established SGAW biosensor. A setup with these features could significantly contribute to future developments in the health, food and environmental industries. The second purpose of this work is to describe the state-of-the-art of SGAW biosensors for the detection of pathogens, being this topic an issue of extremely importance for the human health. Finally, the review discuses the commercial availability, trends and future challenges of the SGAW biosensors for such applications.

  3. Colorimetric Assay for the Detection of Typical Biomarkers for Periodontitis Using a Magnetic Nanoparticle Biosensor.

    Science.gov (United States)

    Wignarajah, Shayalini; Suaifan, Ghadeer A R Y; Bizzarro, Sergio; Bikker, Floris J; Kaman, Wendy E; Zourob, Mohammed

    2015-12-15

    Periodontitis is a chronic disease which affects at least 10% of the population. If untreated, periodontitis can lead to teeth loss. Unfortunately, current diagnostic tests are limited in their sensitivity and specificity. In this study, a novel multiplex hand-held colorimetric diagnostic biosensor, using two typical inflammatory salivary biomarkers, Human Neutrophil Elastase (HNE) and Cathepsin-G, was constructed as proof of concept to potentially detect periodontitis. The biosensing method was based on the measurement of proteolytic activity using specific proteases probes. These probes consist of specific proteases substrates covalently bound to a magnetic bead from one end and to the gold sensor surface by the other end. When intact, this renders the golden sensor black. Upon proteolysis, the cleaved magnetic beads will be attracted by an external magnet revealing the golden color of the sensor surface observable by the naked eye. The biosensor was capable of specific and quantitative detection of HNE and Cathepsin-G in solution and in spiked saliva samples with a lower detection limit of 1 pg/mL and 100 fg/mL for HNE and Cathepsin-G, respectively. Examination of periodontitis patients' sample and a healthy control showed the potential of the multiplex biosensor to detect the presence of HNE and Cathepsin-G activity in situ. This approach is anticipated to be a useful biochip array amenable to low-cost point-of-care devices.

  4. Detection of Interferon gamma using graphene and aptamer based FET-like electrochemical biosensor.

    Science.gov (United States)

    Farid, Sidra; Meshik, Xenia; Choi, Min; Mukherjee, Souvik; Lan, Yi; Parikh, Devanshi; Poduri, Shripriya; Baterdene, Undarmaa; Huang, Ching-En; Wang, Yung Yu; Burke, Peter; Dutta, Mitra; Stroscio, Michael A

    2015-09-15

    One of the primary goals in the scientific community is the specific detection of proteins for the medical diagnostics and biomedical applications. Interferon-gamma (IFN-γ) is associated with the tuberculosis susceptibility, which is one of the major health problems globally. We have therefore developed a DNA aptamer-based electrochemical biosensor that is used for the detection of IFN-γ with high selectivity and sensitivity. A graphene monolayer-based FET-like structure is incorporated on a PDMS substrate with the IFN-γ aptamer attached to graphene. Addition of target molecule induces a change in the charge distribution in the electrolyte, resulting in increase in electron transfer efficiency that was actively sensed by monitoring the change in current from the device. Change in current appears to be highly sensitive to the IFN-γ concentrations ranging from nanomolar (nM) to micromolar (μM) range. The detection limit of our IFN-γ electrochemical biosensor is found to be 83 pM. Immobilization of aptamer on graphene surface is verified using unique structural approach by Atomic Force Microscopy. Such simple and sensitive electrochemical biosensor has potential applications in infectious disease monitoring, immunology and cancer research in the future.

  5. Gold and TiO2 Nanostructurated Surfaces for Assembling of Electrochemical Biosensors

    Directory of Open Access Journals (Sweden)

    Antonella Curulli

    2008-01-01

    Full Text Available Devices based on nanomaterials 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 nanomaterials such as gold nanowires and TiO2 nanostructured films to be used for assembling of electrochemical biosensors. Gold nanowires were prepared by electroless deposition within the pores of polycarbonate particle track-etched membranes (PTMs. Glucose oxidase was deposited onto the nanowires 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 nanowires as biosensors. Considering another interesting nanomaterial, the realization of functionalised TiO2 thin films on Si substrates for the immobilization of enzymes is reported. Glucose oxidase and horseradish peroxidase immobilized onto TiO2-based nanostructured surfaces exhibited a pair of well-defined and quasireversible voltammetric peaks. The electron exchange between the enzyme and the electrodes was greatly enhanced in the TiO2 nanostructured environment. The electrocatalytic activity of HRP and GOD embedded in TiO2 electrodes toward H2O2 and glucose, respectively, may have a potential perspective in the fabrication of third-generation biosensors based on direct electrochemistry of enzymes.

  6. Graphene-like two-dimensional layered nanomaterials: applications in biosensors and nanomedicine

    Science.gov (United States)

    Yang, Guohai; Zhu, Chengzhou; Du, Dan; Zhu, Junjie; Lin, Yuehe

    2015-08-01

    The development of nanotechnology provides promising opportunities for various important applications. The recent discovery of atomically-thick two-dimensional (2D) nanomaterials can offer manifold perspectives to construct versatile devices with high-performance to satisfy multiple requirements. Many studies directed at graphene have stimulated renewed interest on graphene-like 2D layered nanomaterials (GLNs). GLNs including boron nitride nanosheets, graphitic-carbon nitride nanosheets and transition metal dichalcogenides (e.g. MoS2 and WS2) have attracted significant interest in numerous research fields from physics and chemistry to biology and engineering, which has led to numerous interdisciplinary advances in nano science. Benefiting from the unique physical and chemical properties (e.g. strong mechanical strength, high surface area, unparalleled thermal conductivity, remarkable biocompatibility and ease of functionalization), these 2D layered nanomaterials have shown great potential in biochemistry and biomedicine. This review summarizes recent advances of GLNs in applications of biosensors and nanomedicine, including electrochemical biosensors, optical biosensors, bioimaging, drug delivery and cancer therapy. Current challenges and future perspectives in these rapidly developing areas are also outlined. It is expected that they will have great practical foundation in biomedical applications with future efforts.

  7. The Design, Development and Characterisation of a new Biosensor for In-vivo Neurochemical Monitoring of ᴅ-Serine

    OpenAIRE

    Pierce, Kenneth W.

    2012-01-01

    The desire to monitor important neurotransmitters in the in vivo environment, in real-time and in conscious subjects has been the driving force behind the continued development over the last 40 years of a range of biosensor devices. This is a none too difficult task considering the milieu of substances that are present in vivo, particularly in the brain where there also exists a wide range of electroactive species, and where foreign objects are treated as hostile and subject to severe biologi...

  8. Amperometric biosensors based on carbon composite transducers

    Science.gov (United States)

    Lu, Fang

    1998-12-01

    Much current work in analytical chemistry is devoted to design of biosensors. One particular area in this field is the development of enzyme-based amperometric biosensors for the quantitative determination of a series of substrates in clinical, environmental, industrial and agricultural significance. This dissertation focuses on the design of improved amperometric biosensors based on carbon composite transducers. The use of metallized carbons as transducer materials results in remarkably selective amperometric biosensors. Such enzyme-based transducers eliminate major electroactive interferences, and hence circumvent the need for mediators or membrane barriers. The remarkable selectivity of metal-dispersed carbons is attributed to their strong, preferential, electrocatalytic capacity towards the reductive detection of biologically-generated hydrogen peroxide. Such electrocatalytic activity allows metal-dispersed biosensors to be operated at the optimal potential region between +0.1 and -0.2 V, where the unwanted reactions are neglected resulting in the lowest noise level. Several new materials (e.g., ruthenium on carbon, rhodium on carbon, etc.) and constructions (e.g., carbon fiber, electrochemical co-deposition transducer, etc.) were applied in the development of novel enzyme-based transducers in order to improve the selectivity and applicability of amperometric biosensors. The susceptibility of first-generation oxidase amperometric biosensing to oxygen fluctuations can be improved by using oxygen-rich fluorocarbons as the pasting binders in carbon paste enzyme transducers. Such binders provide an internal supply of oxygen resulting in efficient detection in oxygen-deficit conditions. In particular, the use of poly-chlorotrifluorethylene (Kel-F) oil as carbon paste binder results in a well-defined response and an identical signal up to 40 mM glucose in both the presence and absence of oxygen. Comparing with mediated or wired enzyme-based transducers, such internal

  9. Recent advances in graphene-based biosensors.

    Science.gov (United States)

    Kuila, Tapas; Bose, Saswata; Khanra, Partha; Mishra, Ananta Kumar; Kim, Nam Hoon; Lee, Joong Hee

    2011-08-15

    A detailed overview towards the advancement of graphene based biosensors has been reviewed. The large surface area and excellent electrical conductivity of graphene allow it to act as an "electron wire" between the redox centers of an enzyme or protein and an electrode's surface. Rapid electron transfer facilitates accurate and selective detection of biomolecules. This review discusses the application of graphene for the detection of glucose, Cyt-c, NADH, Hb, cholesterol, AA, UA, DA, and H(2)O(2). GO and RGO have been used for the fabrication of heavy metal ion sensors, gas sensors, and DNA sensors. Graphene based FETs have also been discussed in details. In all these cases, the biosensors performed well with low working potentials, high sensitivities, low detection limits, and long-term stabilities. PMID:21683572

  10. Modelling Carbon Nanotubes-Based Mediatorless Biosensor

    Directory of Open Access Journals (Sweden)

    Julija Razumiene

    2012-07-01

    Full Text Available This paper presents a mathematical model of carbon nanotubes-based mediatorless biosensor. The developed model is based on nonlinear non-stationary reaction-diffusion equations. The model involves four layers (compartments: a layer of enzyme solution entrapped on a terylene membrane, a layer of the single walled carbon nanotubes deposited on a perforated membrane, and an outer diffusion layer. The biosensor response and sensitivity are investigated by changing the model parameters with a special emphasis on the mediatorless transfer of the electrons in the layer of the enzyme-loaded carbon nanotubes. The numerical simulation at transient and steady state conditions was carried out using the finite difference technique. The mathematical model and the numerical solution were validated by experimental data. The obtained agreement between the simulation results and the experimental data was admissible at different concentrations of the substrate.

  11. Bioconjugation and stabilisation of biomolecules in biosensors.

    Science.gov (United States)

    Liébana, Susana; Drago, Guido A

    2016-06-30

    Suitable bioconjugation strategies and stabilisation of biomolecules on electrodes is essential for the development of novel and commercially viable biosensors. In the present review, the functional groups that comprise the selectable targets for practical bioconjugation methods are discussed. We focus on describing the most common immobilisation techniques used in biosensor construction, which are classified into irreversible and reversible methods. Concerning the stability of proteins, the two main types of stability may be defined as (i) storage or shelf stability, and (ii) operational stability. Both types of stability are explained, as well as the introduction of an electrophoretic technique for predicting protein-polymer interactions. In addition, solution and dry stabilisation as well as stabilisation using the covalent immobilisation of proteins are discussed including possible factors that influence stability. Finally, the integration of nanomaterials, such as magnetic particles, with protein immobilisation is discussed in relation to protein stability studies. PMID:27365036

  12. Modelling carbon nanotubes-based mediatorless biosensor.

    Science.gov (United States)

    Baronas, Romas; Kulys, Juozas; Petrauskas, Karolis; Razumiene, Julija

    2012-01-01

    This paper presents a mathematical model of carbon nanotubes-based mediatorless biosensor. The developed model is based on nonlinear non-stationary reaction-diffusion equations. The model involves four layers (compartments): a layer of enzyme solution entrapped on a terylene membrane, a layer of the single walled carbon nanotubes deposited on a perforated membrane, and an outer diffusion layer. The biosensor response and sensitivity are investigated by changing the model parameters with a special emphasis on the mediatorless transfer of the electrons in the layer of the enzyme-loaded carbon nanotubes. The numerical simulation at transient and steady state conditions was carried out using the finite difference technique. The mathematical model and the numerical solution were validated by experimental data. The obtained agreement between the simulation results and the experimental data was admissible at different concentrations of the substrate. PMID:23012537

  13. Biosensor for Pesticides Based on Valerolacton Copolymer

    Directory of Open Access Journals (Sweden)

    Yotova L.

    2007-12-01

    Full Text Available A construction of amperometric biosensor based on immobilized acetycholinesterase and cholin oxidase is described and its application in the detection of organophosphate pesticides through enzyme inhibition measurements is discussed. The bioactive component of the sensor consists of acetycholinesterase or cholin oxidase covalently immobilized on two types new polymeric synthetic membranes. Two types of the copolymers were used for the synthesis of membranes - the copolymer of polyacrylamide and acrylonitrile and the new copolymer of poly- (hexanlactam-co-block-poly-(delta-valerolactone with aliphatic polyester. It is investigated the technical characteristics of biosensor like, response time, linear range and operating stability. The factors affecting the inhibition and reactivation processes were investigated too.

  14. Recent advances in biosensor based endotoxin detection.

    Science.gov (United States)

    Das, A P; Kumar, P S; Swain, S

    2014-01-15

    Endotoxins also referred to as pyrogens are chemically lipopolysaccharides habitually found in food, environment and clinical products of bacterial origin and are unavoidable ubiquitous microbiological contaminants. Pernicious issues of its contamination result in high mortality and severe morbidities. Standard traditional techniques are slow and cumbersome, highlighting the pressing need for evoking agile endotoxin detection system. The early and prompt detection of endotoxin assumes prime importance in health care, pharmacological and biomedical sectors. The unparalleled recognition abilities of LAL biosensors perched with remarkable sensitivity, high stability and reproducibility have bestowed it with persistent reliability and their possible fabrication for commercial applicability. This review paper entails an overview of various trends in current techniques available and other possible alternatives in biosensor based endotoxin detection together with its classification, epidemiological aspects, thrust areas demanding endotoxin control, commercially available detection sensors and a revolutionary unprecedented approach narrating the influence of omics for endotoxin detection. PMID:23934306

  15. The evolution of urgency-based and functionally referential alarm calls in ground-dwelling species.

    Science.gov (United States)

    Furrer, Roman D; Manser, Marta B

    2009-03-01

    A major evolutionary force driving functionally referential alarm calls is the need for different strategies to escape various predator types in complex structured habitats. In contrast, a single escape strategy appears to be sufficient in less-structured open habitats, and under such conditions urgency-dependent alarm calls may be favored. Nevertheless, some species, such as meerkats (Suricata suricatta), have evolved functionally referential alarm calls despite living in open areas, using only bolt-holes for retreat. To understand the evolution of different alarm call systems, we investigated the calls of sympatric Cape ground squirrels (Xerus inauris) and compared their antipredator and foraging behavior with that of meerkats. Cape ground squirrels emitted urgency-dependent alarm calls and responded to playbacks depending on urgency, not predator type. Vigilance behavior and habitat use differed between the two species. Meerkats roam widely to find prey and for efficient foraging depend on coordinated predator vigilance and escape behavior. As herbivores with smaller territories, Cape ground squirrels depend less on coordinated antipredator behavior, and urgency-dependent alarm calls encode all essential information. We conclude that habitat complexity does not explain the evolution of functionally referential alarm calls in all species, and other constraints, such as the need to coordinate group movements to maintain foraging efficiency, could be more relevant. PMID:19199527

  16. Effect of vibratory soldier alarm signals on the foraging behavior of subterranean termites (Isoptera: Rhinotermitidae).

    Science.gov (United States)

    Inta, R; Evans, T A; Lai, J C S

    2009-02-01

    Termite soldiers produce a vibratory alarm signal to warn conspecific workers. This study recorded and characterized the alarm signals of Coptotermes acinaciformis (Froggatt) (Isoptera: Rhinotermitidae) and then investigated the effect of playing these recorded alarm signals on C. acinaciformis feeding activity. Foraging groups of termites were offered paired wooden blocks: either one block, continuously stimulated with a vibratory alarm signal, paired with a nonstimulated block (the alarm treatment), continuously stimulated with a pink noise signal, paired with a nonstimulated block (control for nonspecific vibrations) or two nonstimulated blocks (control for environmental effects), for 4 wk. The amount of wood eaten in the blocks stimulated by the alarm signals was significantly less than the paired nonstimulated blocks, while there seemed to be no preference in the case of the pink noise playback or control for direction. Importantly, the termites seemed not to have adapted to the recorded alarm signal over the 4-wk duration of the experiment, unlike previous studies using nonbiologically derived signals. PMID:19253626

  17. Nanomaterial-mediated Biosensors for Monitoring Glucose

    OpenAIRE

    Taguchi, Masashige; Ptitsyn, Andre; McLamore, Eric S.; Claussen, Jonathan C.

    2014-01-01

    Real-time monitoring of physiological glucose transport is crucial for gaining new understanding of diabetes. Many techniques and equipment currently exist for measuring glucose, but these techniques are limited by complexity of the measurement, requirement of bulky equipment, and low temporal/spatial resolution. The development of various types of biosensors (eg, electrochemical, optical sensors) for laboratory and/or clinical applications will provide new insights into the cause(s) and poss...

  18. Mathematical Modeling of Multienzyme Biosensor System

    OpenAIRE

    SP. Ganesan; K Saravanakumar; Rajendran, L.

    2014-01-01

    A mathematical model of hybrid inhibitor biosensor system is discussed. This model consists of five nonlinear partial differential equations for bisubstrate sensitive amperometric system. Simple and closed form of analytical expressions for concentration of glucose-6-phosphate (substrate), potassium dihydrogen phosphate (inhibitor), oxygen (co-substrate), glucose (product 1), and hydrogen peroxide (product 3) is obtained in terms of rate constant using modified Adomian decomposition method (M...

  19. Integrated biosensors for cell culture monitoring

    OpenAIRE

    De Micheli, Giovanni; Boero, Cristina; Olivo, Jacopo; Carrara, Sandro

    2014-01-01

    Biosensors for endogenous compounds, such as glucose and lactate, are applied to monitor cell cultures. Cells can be cultivated for several purposes, such as understanding and modeling some biological mechanisms, the development of new drugs and therapies, and in the field of regenerative medicine. We have realized a self-contained monitoring system with remote readout. Metabolite detection is based on oxidases immobilized onto carbon nanotubes. We calibrate the system for glucose and lactate...

  20. Single bead-based electrochemical biosensor

    OpenAIRE

    LIU, CHANGCHUN; Schrlau, Michael G.; Bau, Haim H.

    2009-01-01

    A simple, robust, single bead-based electrochemical biosensor was fabricated and characterized. The sensor’s working electrode consists of an electrochemically-etched platinum wire, with a nominal diameter of 25 μm, hermetically heat-fusion sealed in a pulled glass capillary (micropipette). The sealing process does not require any epoxy or glue. A commercially available, densely functionalized agarose bead was mounted on the tip of the etched platinum wire. The use of a pre-functionalized bea...

  1. Feasibility Studies on Si-Based Biosensors

    OpenAIRE

    Marcella Renis; Fulvia Sinatra; Antonino Scandurra; Venera Aiello; Sebania Libertino; Salvatore Lombardo

    2009-01-01

    The aim of this paperis to summarize the efforts carried out so far in the fabrication of Si-based biosensors by a team of researchers in Catania, Italy. This work was born as a collaboration between the Catania section of the Microelectronic and Microsystem Institute (IMM) of the CNR, the Surfaces and Interfaces laboratory (SUPERLAB) of the Consorzio Catania Ricerche and two departments at the University of Catania: the Biomedical Science and the Biological Chemistry and Molecular Biology De...

  2. Biosensors for the Detection of Food Pathogens

    OpenAIRE

    Palmiro Poltronieri; Valeria Mezzolla; Elisabetta Primiceri; Giuseppe Maruccio

    2014-01-01

    Food pathogens frequently cause foodborne diseases. There is a need to rapidly identify the source of the bacteria in order to contain their spread and epidemics. A pre-enrichment culture or a direct culture on agar plate are standard microbiological methods. In this review, we present an update on alternative molecular methods to nucleic acid-based detection for species identification. Biosensor-based methods rely on the recognition of antigen targets or receptors by antibodies, aptamers o...

  3. Aptamer Based Microsphere Biosensor for Thrombin Detection

    OpenAIRE

    Xudong Fan; White, Ian M.; Suter, Jonathan D.; Hongying Zhu

    2006-01-01

    We have developed an optical microsphere resonator biosensor using aptamer as receptor for the measurement of the important biomolecule thrombin. The sphere surface is modified with anti-thrombin aptamer, which has excellent binding affinity and selectivity for thrombin. Binding of the thrombin at the sphere surface is monitored by the spectral position of the microsphere's whispering gallery mode resonances. A detection limit on the order of 1 NIH Unit/mL is demonstrated. Control experiments...

  4. Hybrid nano plasmonics for integrated biosensor

    Science.gov (United States)

    Lin, Chii-Wann; Lee, Jun-Haw; Chiu, Nan-Fu; Lee, Szu-Yuan; Liu, Kou-Chen; Tsai, Feng-Yu; Yen, Chia-Yu; Lee, Chun-Nan

    2009-11-01

    SPR biosensor with OLED and nano-grating for HBV LAMP product detection is reported. Directional emissions by grating-coupler match the resonant condition of SP modes. Concentration changes result in color shift at specific angle. Real time detection of virus load down to 5 copies/25 ul can be achieved in 30 minutes. Surface plasmon Resonant (SPR) biosensor has been used for quantitative measurement of molecular interactions for its advantages of high sensitivity, label-free and real-time detection. In this paper, we report recent efforts on further enhancement of SPR biosensors by the heterogeneous integration of organic electroluminescence light source and nano-grating structure for the feasibility study on the fast and high sensitivity detection of HBV isothermal amplification products, Mg2P2O7. We demonstrated the surface plasmon coupled through hybrid nano-grating structure has highly directional emissions corresponding to the resonant condition of surface plasmon modes on the Au/air interface and controllable plasmonics band-gap by pitch modulation. SPGCE resulted in color change from yellowish green to orange at a certain viewing angle, when contacting glucose with concentration increasing from 10 to 40%.

  5. Scalable Production of Molybdenum Disulfide Based Biosensors.

    Science.gov (United States)

    Naylor, Carl H; Kybert, Nicholas J; Schneier, Camilla; Xi, Jin; Romero, Gabriela; Saven, Jeffery G; Liu, Renyu; Johnson, A T Charlie

    2016-06-28

    We demonstrate arrays of opioid biosensors based on chemical vapor deposition grown molybdenum disulfide (MoS2) field effect transistors (FETs) coupled to a computationally redesigned, water-soluble variant of the μ-opioid receptor (MOR). By transferring dense films of monolayer MoS2 crystals onto prefabricated electrode arrays, we obtain high-quality FETs with clean surfaces that allow for reproducible protein attachment. The fabrication yield of MoS2 FETs and biosensors exceeds 95%, with an average mobility of 2.0 cm(2) V(-1) s(-1) (36 cm(2) V(-1) s(-1)) at room temperature under ambient (in vacuo). An atomic length nickel-mediated linker chemistry enables target binding events that occur very close to the MoS2 surface to maximize sensitivity. The biosensor response calibration curve for a synthetic opioid peptide known to bind to the wild-type MOR indicates binding affinity that matches values determined using traditional techniques and a limit of detection ∼3 nM (1.5 ng/mL). The combination of scalable array fabrication and rapid, precise binding readout enabled by the MoS2 transistor offers the prospect of a solid-state drug testing platform for rapid readout of the interactions between novel drugs and their intended protein targets. PMID:27227361

  6. Porous photonic crystal external cavity laser biosensor

    Science.gov (United States)

    Huang, Qinglan; Peh, Jessie; Hergenrother, Paul J.; Cunningham, Brian T.

    2016-08-01

    We report the design, fabrication, and testing of a photonic crystal (PC) biosensor structure that incorporates a porous high refractive index TiO2 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.

  7. Sensitive-cell-based fish chromatophore biosensor

    Science.gov (United States)

    Plant, Thomas K.; Chaplen, Frank W.; Jovanovic, Goran; Kolodziej, Wojtek; Trempy, Janine E.; Willard, Corwin; Liburdy, James A.; Pence, Deborah V.; Paul, Brian K.

    2004-07-01

    A sensitive biosensor (cytosensor) has been developed based on color changes in the toxin-sensitive colored living cells of fish. These chromatophores are highly sensitive to the presence of many known and unknown toxins produced by microbial pathogens and undergo visible color changes in a dose-dependent manner. The chromatophores are immobilized and maintained in a viable state while potential pathogens multiply and fish cell-microbe interactions are monitored. Low power LED lighting is used to illuminate the chromatophores which are magnified using standard optical lenses and imaged onto a CCD array. Reaction to toxins is detected by observing changes is the total area of color in the cells. These fish chromatophores are quite sensitive to cholera toxin, Staphococcus alpha toxin, and Bordatella pertussis toxin. Numerous other toxic chemical and biological agents besides bacterial toxins also cause readily detectable color effects in chromatophores. The ability of the chromatophore cell-based biosensor to distinguish between different bacterial pathogens was examined. Toxin producing strains of Salmonella enteritis, Vibrio parahaemolyticus, and Bacillus cereus induced movement of pigmented organelles in the chromatophore cells and this movement was measured by changes in the optical density over time. Each bacterial pathogen elicited this measurable response in a distinctive and signature fashion. These results suggest a chromatophore cell-based biosensor assay may be applicable for the detection and identification of virulence activities associated with certain air-, food-, and water-borne bacterial pathogens.

  8. 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

  9. Biosensor UUV payload for underwater detection

    Science.gov (United States)

    Kusterbeck, Anne W.; Charles, Paul T.; Melde, Brian J.; Trammell, Scott A.; Adams, André A.; Deschamps, Jeffrey R.

    2010-04-01

    Increased emphasis on maritime domain awareness and port security has led to the development of unmanned underwater vehicles (UUVs) capable of extended missions. These systems rely most frequently on well-developed side scan sonar and acoustic methods to locate potential targets. The Naval Research Laboratory (NRL) is developing biosensors for underwater explosives detection that complement acoustic sensors and can be used as UUV payloads to monitor areas for port and harbor security or in detection of underwater unexploded ordnance (UXO) and biochemical threats. The prototype sensor has recently been demonstrated to detect explosives in seawater at trace levels when run in a continuous sampling mode. To overcome ongoing issues with sample preparation and facilitate rapid detection at trace levels in a marine environment, we have been developing new mesoporous materials for in-line preconcentration of explosives and other small molecules, engineering microfluidic components to improve the signal, and testing alternative signal transduction methods. Additional work is being done to optimize the optical components and sensor response time. Highlights of these current studies and our ongoing efforts to integrate the biosensor with existing detection technologies to reduce false positives are described. In addition, we present the results of field tests that demonstrate the prototype biosensor performance as a UUV payload.

  10. An efficient biosensor made of an electromagnetic trap and a magneto-resistive sensor

    KAUST Repository

    Li, Fuquan

    2014-09-01

    Magneto-resistive biosensors have been found to be useful because of their high sensitivity, low cost, small size, and direct electrical output. They use super-paramagnetic beads to label a biological target and detect it via sensing the stray field. In this paper, we report a new setup for magnetic biosensors, replacing the conventional "sandwich" concept with an electromagnetic trap. We demonstrate the capability of the biosensor in the detection of E. coli. The trap is formed by a current-carrying microwire that attracts the magnetic beads into a sensing space on top of a tunnel magneto-resistive sensor. The sensor signal depends on the number of beads in the sensing space, which depends on the size of the beads. This enables the detection of biological targets, because such targets increase the volume of the beads. Experiments were carried out with a 6. μm wide microwire, which attracted the magnetic beads from a distance of 60. μm, when a current of 30. mA was applied. A sensing space of 30. μm in length and 6. μm in width was defined by the magnetic sensor. The results showed that individual E. coli bacterium inside the sensing space could be detected using super-paramagnetic beads that are 2.8. μm in diameter. The electromagnetic trap setup greatly simplifies the device and reduces the detection process to two steps: (i) mixing the bacteria with magnetic beads and (ii) applying the sample solution to the sensor for measurement, which can be accomplished within about 30. min with a sample volume in the μl range. This setup also ensures that the biosensor can be cleaned easily and re-used immediately. The presented setup is readily integrated on chips via standard microfabrication techniques. © 2014 Elsevier B.V.

  11. Assessment of goat milk adulteration with a label-free monolithically integrated optoelectronic biosensor.

    Science.gov (United States)

    Angelopoulou, Μichailia; Botsialas, Athanasios; Salapatas, Alexandros; Petrou, Panagiota S; Haasnoot, Willem; Makarona, Eleni; Jobst, Gerhard; Goustouridis, Dimitrios; Siafaka-Kapadai, Athanasia; Raptis, Ioannis; Misiakos, Konstantinos; Kakabakos, Sotirios E

    2015-05-01

    The label-free detection of bovine milk in goat milk through a miniaturized optical biosensor is presented. The biosensor consists of ten planar silicon nitride waveguide Broad-Band Mach-Zehnder interferometers (BB-MZIs) monolithically integrated and self-aligned with their respective silicon LEDs on the same Si chip. The BB-MZIs were transformed to biosensing transducers by functionalizing their sensing arm with bovine k-casein. Measurements were performed by continuously recording the transmission spectra of each interferometer through an external spectrometer. The amount of bovine milk in goat milk was determined through a competitive immunoassay by passing over the sensor mixtures of anti-k-casein antibodies with the calibrators or the samples. The output spectra of each BB-MZI recorded during the reaction were subjected to Discrete Fourier Transform in order to convert the observed spectral shifts to phase shifts in the wavenumber domain. The method had a detection limit of 0.04 % (v/v) bovine milk in goat milk, dynamic range 0.1-1.0 % (v/v), recoveries 93-110 %, and intra- and inter-assay coefficients of variation less than 12 and 15 %, respectively. The proposed biosensor compared well in terms of analytical performance with a competitive ELISA developed using the same monoclonal antibodies. Nevertheless, the duration of the biosensor assay was 10 min whereas the ELISA required 2 h. Thus, the fast and sensitive determinations along with the small size of the sensor make it ideal for incorporation into portable devices for assessment of goat or ewe's milk adulteration with bovine milk at the point-of-need. PMID:25796524

  12. Detection of Waterborne and Airborne Formaldehyde: From Amperometric Chemosensing to a Visual Biosensor Based on Alcohol Oxidase

    Directory of Open Access Journals (Sweden)

    Sasi Sigawi

    2014-02-01

    Full Text Available A laboratory prototype of a microcomputer-based analyzer was developed for quantitative determination of formaldehyde in liquid samples, based on catalytic chemosensing elements. It was shown that selectivity for the target analyte could be increased by modulating the working electrode potential. Analytical parameters of three variants of the amperometric analyzer that differed in the chemical structure/configuration of the working electrode were studied. The constructed analyzer was tested on wastewater solutions that contained formaldehyde. A simple low-cost biosensor was developed for semi-quantitative detection of airborne formaldehyde in concentrations exceeding the threshold level. This biosensor is based on a change in the color of a solution that contains a mixture of alcohol oxidase from the yeast Hansenula polymorpha, horseradish peroxidase and a chromogen, following exposure to airborne formaldehyde. The solution is enclosed within a membrane device, which is permeable to formaldehyde vapors. The most efficient and sensitive biosensor for detecting formaldehyde was the one that contained alcohol oxidase with an activity of 1.2 U·mL−1. The biosensor requires no special instrumentation and enables rapid visual detection of airborne formaldehyde at concentrations, which are hazardous to human health.

  13. Compact surface plasmon resonance biosensor utilizing an injection-molded prism

    Science.gov (United States)

    Chen, How-Foo; Chen, Chih-Han; Chang, Yun-Hsiang; Chuang, Hsin-Yuan

    2016-05-01

    Targeting at a low cost and accessible diagnostic device in clinical practice, a compact surface plasmon resonance (SPR) biosensor with a large dynamic range in high sensitivity is designed to satisfy commercial needs in food safety, environmental bio-pollution monitoring, and fast clinical diagnosis. The core component integrates an optical coupler, a sample-loading plate, and angle-tuning reflectors is injection-molded as a free-from prism made of plastic optics. This design makes a matching-oil-free operation during operation. The disposability of this low-cost component ensures testing or diagnosis without cross contamination in bio-samples.

  14. Flavin and porphyrin-micro optical fibre biosensor: analysis and design

    Science.gov (United States)

    Velazquez-Gonzalez, J. S.; Mujica-Ascencio, S.; Aguilar Morales, A. I.; Marrujo-Garcia, S.; Alvarez-Chavez, J. A.; Martinez-Pinon, F.

    2014-05-01

    Micro Optical Fibre Biosensors (MOFBs) are emerging as one of the most sensitive bio-detection system technologies which do not require of labelling or amplification of the analyte. In these devices, a short region of the fibre core is exposed to the external environment so that the evanescent field can interact with biological species such as cells, proteins, and DNA. In order to increase the sensitivity and selectivity, MOFBs are often used in combination with other optical transduction mechanisms such as changes in refractive index, absorption, fluorescence and surface plasmon resonance. In this work we present the full characteristics, analysis and design of a MOFBs for Flavin and Porphyrin detection.

  15. Passive micromixers and organic electrochemical transistors for biosensor applications

    Science.gov (United States)

    Kanakamedala, Senaka Krishna

    Fluid handling at the microscale has greatly affected different fields such as biomedical, pharmaceutical, biochemical engineering and environmental monitoring due to its reduced reagent consumption, portability, high throughput, lower hardware cost and shorter analysis time compared to large devices. The challenges associated with mixing of fluids in microscale enabled us in designing, simulating, fabricating and characterizing various micromixers on silicon and flexible polyester substrates. The mixing efficiency was evaluated by injecting the fluids through the two inlets and collecting the sample at outlet. The images collected from the microscope were analyzed, and the absorbance of the color product at the outlet was measured to quantify the mixing efficacy. A mixing efficiency of 96% was achieved using a flexible disposable micromixer. The potential for low-cost processing and the device response tuning using chemical doping or synthesis opened doorways to use organic semiconductor devices as transducers in chemical and biological sensor applications. A simple, inexpensive organic electrochemical transistor (OECT) based on conducting polymer poly(3,4- ethyelenedioxythiphene) poly(styrene sulfonate) (PEDOT:PSS) was fabricated using a novel one step fabrication method. The developed transistor was used as a biosensor to detect glucose and glutamate. The developed glucose sensor showed a linear response for the glucose levels ranging from 1 muM-10 mM and showed a decent response for the glucose levels similar to those found in human saliva and to detect glutamate released from brain tumor cells. The developed glutamate sensor was used to detect the glutamate released from astrocytes and glioma cells after stimulation, and the results are compared with fluorescent spectrophotometer. The developed sensors employ simple fabrication, operate at low potentials, utilize lower enzyme concentrations, do not employ enzyme immobilization techniques, require only 5 muL of

  16. Design of fire alarm system based on Wireless Sensor Network%基于无线传感网络的火警系统设计

    Institute of Scientific and Technical Information of China (English)

    唐杰; 边鹏飞; 何志琴

    2015-01-01

    For the traditional fire alarm device,there are several shortcomings: complicated wiring, circuit is easy to aging, line is easily affected by the environment and high cost of maintenance.In recent years,wireless sensor network has become the most important application technology in environmental monitoring,home and factory automation. This paper presents a design scheme of using multiple sensor module for fire alarm information collection,transmitting the data by wireless sensor network and processing data in order to achieve the rapid fire alarm.%对于传统的火灾报警装置来说,存在着布线复杂,线路容易老化,线路容易受火场环境影响,维护成本高等不足之处。近年来无线传感网络在环境监测、家庭和工厂自动化领域已经成为最重要的应用技术。提出了一种使用多种传感器模块对火警信息进行数据采集,利用无线传感网络对数据进行传输并对数据进行处理,从而实现火灾的快速报警的设计方案。

  17. Homemade Bienzymatic-Amperometric Biosensor for Beverages Analysis

    Science.gov (United States)

    Blanco-Lopez, M. C.; Lobo-Castanon, M. J.; Miranda-Ordieres, A. J.

    2007-01-01

    The construction of an amperometric biosensor for glucose analysis is described demonstrating that the analysis is easy to perform and the biosensor gives good analytical performance. This experiment helped the students to acquire problem-solving and teamwork skills, allowing them to reach a high level of independent and critical thought.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kros, A.; Nolte, R.J.M. [Nijmegen Univ. (Netherlands). Dept. of Organic Chemistry; Hoevell, S.W.F.M. van [TNO Nutrition and Food Research Inst., Zeist (Netherlands); Sommerdijk, N.A.J.M. [Eindhoven Univ. of Technology (Netherlands). Lab. of Macromolecular and Organic Chemistry

    2001-10-16

    Amperometric biosensors for the recognition of glucose oxidase (GOx) based on poly(3,4-ethylenedioxythiophene) (PEDOT) have for the first time been fabricated and are presented in this communication. This biosensor has potential applications for long-term glucose measurements, e.g., in the treatment of diabetes. (orig.)

  19. In vitro evaluation of fluorescence glucose biosensor response.

    Science.gov (United States)

    Aloraefy, Mamdouh; Pfefer, T Joshua; Ramella-Roman, Jessica C; Sapsford, Kim E

    2014-01-01

    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 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. PMID:25006996

  20. Design Strategies of Fluorescent Biosensors Based on Biological Macromolecular Receptors

    Directory of Open Access Journals (Sweden)

    Takashi Morii

    2010-02-01

    Full Text Available Fluorescent biosensors to detect the bona fide events of biologically important molecules in living cells are increasingly demanded in the field of molecular cell biology. Recent advances in the development of fluorescent biosensors have made an outstanding contribution to elucidating not only the roles of individual biomolecules, but also the dynamic intracellular relationships between these molecules. However, rational design strategies of fluorescent biosensors are not as mature as they look. An insatiable request for the establishment of a more universal and versatile strategy continues to provide an attractive alternative, so-called modular strategy, which permits facile preparation of biosensors with tailored characteristics by a simple combination of a receptor and a signal transducer. This review describes an overview of the progress in design strategies of fluorescent biosensors, such as auto-fluorescent protein-based biosensors, protein-based biosensors covalently modified with synthetic fluorophores, and signaling aptamers, and highlights the insight into how a given receptor is converted to a fluorescent biosensor. Furthermore, we will demonstrate a significance of the modular strategy for the sensor design.