Bioaffinity sensors

Biosensors may be classified into two categories biocatalytic biosensors and bioaffinity biosensors. Biocatalytic sensors contain a biocatalyst such as an enzyme to recognize the analytic selectively. Bioaflinity biosensors, on the other hand, may involve antibody, binding protein or receptor protein, which form stable complexes with the corresponding ligand. An immunosensor in which antibody is used as the receptor may represent a bioaflinity biosensor. 

These preliminary developments have relied on either metabolic enzyme reactions (viz. those where the substrate is consumed and a product is formed as a result) and bioaffinity reactions (viz. those that are followed via electron density changes). This Section discusses sensors based on immobilized enzymes and both types of reaction metabolic and bioaffinity. 

Starodub VM, Fedorenko LL, Starodub NF (1998) Control of a myoglobin level in solution by the bioaffine sensor based on the photoluminescence of porous sihcon. In Proceedings of the european conference on solid-state transducers and 9th UK conference on sensors and their apphcations, Southampton, UK, 2 817-820, 13-16 Sept 1998... 

Pei, Z., Larsson, R., Aastrup, T., Anderson, H., Lehn, J.-M., Ramstrom, O. Quartz crystal microbalance bioaffinity sensor for rapid identification of glycosyldisulfide lectin inhibitors from a dynamic combinatorial library. Biosens. Bioelectron. 2006, 22, 42-48. 

Aizawa presented an overview on the principles and applications of the electrochemical and optical biosensors [61]. The current development in the biocatalytic and bioaffinity bensensor and the applications of these sensors were given. The optical enzyme sensor for acetylcholine was based on use of an optical pH fiber with thin polyaniline film. 

Duveneck GL, Pawlak M, Neuschafer D et al (1997) Novel bioaffinity sensors for trace analysis based on luminescence excitation by planar waveguides. Sensors Actuators B Chem... 

Immobilization provides great flexibility, particularly in the design of enzyme-based bioanalytical systems. Some relatively recent developments in protein immobilization methodology which can be broadly classified as reversible immobilization methods, have resulted in novel analytical approaches such as bioaffinity sensors (7) and flow injection binding reactions (8). 

Lillie, G., Payne, P., and Vadgama, P. (2001) Electrochemical impedance spectroscopy as a platform for reagentless bioaffinity sensing. Sensors and Actuators B, 78 (1-3), 249-256. 

Overview of different bioaffinity-based piezoelectric sensors... 

Duveneck, G. L., Pawlak, M., Neuschafer, D., Bar, E., Budach, W., Pieles, U., and Ehrat, M. (1997) Novel bioaffinity sensors for trace analysis based on luminescence excitation by planar waveguides. Sens. Actuator. B-Chem. 38/39,88-95... 

Masson et al. described a bioaffinity Pz sensor for biotin [174]. The sensor was based on the displacement of avidin from the crystal surface, which caused a large frequency increases when biotin was added to the solution. The surface was easily regenerated by addition of more avidin after analysis. 

Wittmann C. and Schmid R. D., Bioaffinity sensors for enviroiunental monitoring, in Handbook of Biosensors and Electronic Noses—Medicine, Food, and the Environment, ed. E. Kress-Rogers, pp. 333-349. (Boca Raton, FL CRC Press, 1997). 

O. A. Sadik, Bioaffinity sensors based on conducting polymers a short review. Electroanalysis, 11, 839-844 (1999). 

DNA-based biosensors possess specificity of response, which is typical for biosensors taking advantage of the bioaffinity properties of DNA. Compared with enzyme sensors and immunosensors, DNA biosensors are mostly used for the investigation of DNA interactions rather than for conventional determination of the concentration of an anal3 e. They exhibit typical biosensor selec-tivity/specificity to the anal3d e (e.g., nucleotide bases sequence. 

Keywords-. Conducting polymers, nanocomposites, biosensors, immunosen-sors, bioaffinity sensors, DNA biosensors, cholesterol biosensors, glucose biosensors, electrochemical biosensor, sensitivity, response time, recovery time selectivity, reversibility, polyanihne, polypyrrole, graphene, carbon nanotubes, nanoparticles... 

In this paper we describe, for the first time, a self-assembly technique that employs alkyl phosphoric acid esters to produce dense, highly ordered monolayers in a tails-up configuration, on a TazOs surface. Tantalum oxide was chosen because of its high refractive index, which renders it ideal for application in a planar-waveguide-based bioaffinity sensor. Upon appropriate m-function-alization, alkanephosphate-based SAMs have the potential to be used as the interface that anchors active sensing elements or as the basis of passive, biomolecule-resistant regions on the sensor surface. 

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