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Biosensor acoustic

Besides MEMS-based electrochemical and optical biosensors, there are other types of MEMS biosensors acoustic wave, nanomaterial-based, and magnetic microbiosensors. [Pg.1755]

The determination of H202 is very important in many different fields, such as in clinical, food, pharmaceutical, and environmental analyses [202], Many techniques such as spectrophotometry, chemiluminesence, fluorimetry, acoustic emission, and electrochemistry methods have been employed to determine H202. Electrochemical methods are often used because of their advantages. Among these electrochemical methods, the construction of the mediator-free enzyme-based biosensors based on the direct electrochemistry of redox proteins has been reported over the past decade [203— 204], The enzyme-based biosensors, which use cyt c as biocatalyzer to catalyze H202, were widely studied. [Pg.574]

There is increasing interest in the use of specific sensor or biosensor detection systems with the FIA technique (Galensa, 1998). Tsafack et al. (2000) described an electrochemiluminescence-based fibre optic biosensor for choline with flow-injection analysis and Su et al. (1998) reported a flow-injection determination of sulphite in wines and fruit juices using a bulk acoustic wave impedance sensor coupled to a membrane separation technique. Prodromidis et al. (1997) also coupled a biosensor with an FIA system for analysis of citric acid in juices, fruits and sports beverages and Okawa et al. (1998) reported a procedure for the simultaneous determination of ascorbic acid and glucose in soft drinks with an electrochemical filter/biosensor FIA system. [Pg.126]

However, the determination of affinity does not necessarily have to rely on labeled ligands. It is also possible with native ligands when using suitable detection methods, as for example nuclear magnetic resonance (NMR), surface plasmon resonance (SPR), acoustic biosensors or calorimetry [48, 49]. A particularly versatile and sensitive detection principle for the investigation of interactions between targets and native ligands is mass spectrometry [50]. [Pg.253]

Zhou, C., Pivarnik, P., Rand, A. G., and Letcher, S. V. (1998). Acoustic standing-wave enhancement of a fiber-optic Salmonella biosensor. Biosens. Bioelectron. 13, 495-500. [Pg.44]

Heat is the most common product of biological reaction. Heat measurement can avoid the color and turbidity interferences that are the concerns in photometry. Measurements by a calorimeter are cumbersome, but thermistors are simple to use. However, selectivity and drift need to be overcome in biosensor development. Changes in the density and surface properties of the molecules during biological reactions can be detected by the surface acoustic wave propagation or piezoelectric crystal distortion. Both techniques operate over a wide temperature range. Piezoelectric technique provides fast response and stable output. However, mass loading in liquid is a limitation of this method. [Pg.332]

Types of biosensors can be named either by the biological components, physical transducing devices, or the measured analytes. Researchers were originally using biological components to define types of biosensors (Table 2). Types of transducers had also been included in the name to identify the physical transducing device, i.e., enzyme electrodes, acoustic-immunosensors, optical biosensors, piezoelectric-immunosensors, and biochips. [Pg.334]

The packaging (i.e., electrical insulation for operation in electrolytes) is more difficult with SAWs due to their rectangular geometry. SAWs are easier to fabricate with lithographic microfabrication techniques and therefore are more suitable for use in an array (Ricco et al., 1998). The choice of electrode materials is critical for QCM, where acoustic impedance mismatch can result in substantial lowering of the Q factor of the device. On the other hand, it does not play any role in the SAW devices. The energy losses to the condensed medium are higher in SAWs and this fact makes them even less suitable for operation in liquids. Nevertheless, SAW biosensors have been reported (Marx, 2003). [Pg.91]

In this part we will describe recent achievements in the development of biosensors based on DNA/RNA aptamers. These biosensors are usually prepared by immobilization of aptamer onto a solid support by various methods using chemisorption (aptamer is modified by thiol group) or by avidin-biotin technology (aptamer is modified by biotin) or by covalent attachment of amino group-labeled aptamer to a surface of self-assembly monolayer of 11-mercaptoundecanoic acid (11-MUA). Apart from the method of aptamer immobilization, the biosensors differ in the signal generation. To date, most extensively studied were the biosensors based on optical methods (fluorescence, SPR) and acoustic sensors based mostly on thickness shear mode (TSM) method. However, recently several investigators reported electrochemical sensors based on enzyme-labeled aptamers, electrochemical indicators and impedance spectroscopy methods of detection. [Pg.807]

The transducers most commonly employed in biosensors are (a) Electrochemical amperometric, potentiometric and impedimetric (b) Optical vibrational (IR, Raman), luminescence (fluorescence, chemiluminescence) (c) Integrated optics (surface plasmon resonance (SPR), interferometery) and (d) Mechanical surface acoustic wave (SAW) and quartz crystal microbalance (QCM) [4,12]. [Pg.942]

At the present time, transducers are most often electrochemical converters electrodes (ammeter, pH meter and conductometers), various optical, calorimetric and acoustic converters. The existing variety in biosensor types is formed by varying bioselective structures with different transducers. Note that enzyme and cell biosensors are the most widespread. [Pg.290]

Amico A, Natale C, Verona E (1997) Acoustic devices. In Kress Rogers (ed) Handbook of Biosensors and Electronic Noses, Medicine, Food, and the Environment. CRC, Boca Raton, p 197... [Pg.210]

Cooper MA, Singleton VT (2007) A survey of the 2001 to 2005 quartz crystal microbalance biosensor literature applications of acoustic physics to the analysis of biomolecular interactions. J Mol Recognit 20 154—184... [Pg.157]

Acoustic surface wave devices. 2. Detectors. 3. Chemical detectors. 4. Biosensors. I. Ballantine, David Stephen. II. Series. TK5984.A38 1996 96-21931... [Pg.447]

The reaction between the analjrte and the bioreceptor produces a physical or chemical output signal normally relayed to a transducer, which then generally converts it into an electrical signal, providing quantitative information of analytical interest. The transducers can be classified based on the technique utilized for measurement, being optical (absorption, luminescence, surface plasmon resonance), electrochemical, calorimetric, or mass sensitive measurements (microbalance, surface acoustic wave), etc. If the molecular recognition system and the physicochemical transducer are in direct spatial contact, the system can be defined as a biosensor [76]. A number of books have been published on this subject and they provide details concerning definitions, properties, and construction of these devices [77-82]. [Pg.231]

Biosensors presently being developed for the detection of DNA hybridization are mostly based on optical, surface acoustic wave and electrochemical transducers. The detection of specific DNA sequences, using... [Pg.384]

DNA-acoustic wave biosensors have been employed to study the duplex formation at the sensor surface and for monitoring a wide variety of processes involving nucleic acid chemistry at the soUd-liquid interface without the need of labels such as radiochemical or fluorescent agents. The theory and applications of acoustic wave technology were reviewed by Thompson [50,51], Ziegler [52] and co-workers. [Pg.390]

Biosensors based on acoustic transduction have been used mainly for the detection of pathogenic microorganisms such as Escherechia coli (Pyun el al., 1998), other examples of applications involve the use of an acoustic sensor to detect genetically modified organisms (GMO) (Mannelli et al., 2003). [Pg.140]

Biosensors evanescence SPR, absorbance), Electrochemical methods (amperometric, conductimetric, potentiometric), piezoelectric acoustic, colorimetric, mechanical, thermal methods et al., 2002 Baeumner, 2003 Nakamura and Karube, 2003... [Pg.176]


See other pages where Biosensor acoustic is mentioned: [Pg.158]    [Pg.1749]    [Pg.1084]    [Pg.158]    [Pg.1749]    [Pg.1084]    [Pg.670]    [Pg.435]    [Pg.962]    [Pg.81]    [Pg.9]    [Pg.37]    [Pg.337]    [Pg.172]    [Pg.210]    [Pg.822]    [Pg.76]    [Pg.324]    [Pg.306]    [Pg.365]    [Pg.420]    [Pg.390]    [Pg.478]    [Pg.501]    [Pg.517]    [Pg.219]    [Pg.285]   
See also in sourсe #XX -- [ Pg.253 ]




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