Biosensor assembly

A combination of a biosensor assembly such as that described in the previous paragraph and several enzyme reactors allows simultaneous... 

Figure 18 Schematic of a glucose biosensor assembled from diphenylalanine peptide nanotubes. The enzyme GOX has been cross-linked to these nanotubes, which are further linked to the gold (Au) electrode and immobilized in a polyethyleneimine (PEI) matrix. The nanofibers act in two ways they immobilize the sensing enzyme and enhance the transducer. Reprinted in part with permission from Yemini et al. (2005a) (copyright 2005 American Chemical Society).

Li D, M W Frey and A J Baeumner, Electrospun polylactic acid nanofibre membrane as substrates for biosensor assemblies , J Membrane Science, 2006 279(1-2) 354-363. 

Li, D., Frey, M.W. and Baeumner, A.J. 2006a. Electrospun polylactic acid nanofiber membranes as substrates for biosensor assemblies.. f.Memh.Sci. 279 354-363. 

Rguro 1 Biosensor assembly based on the Clark oxygen electrode. A, dialysis membrane B, bacteria-loaded tortuous filter C, PTFE membrane D, platinum electrode E, O ring F, silver/ silver chloride electrode G, potassium chloride solution. 

DNA or RNA aptamers - the single stranded nucleic acids with high affinity to proteins or to other low and macromolecular compounds, which is comparable with that of antibodies. These special characteristics open new routes in biosensor assembling for further practical applications, such as detection of toxicants in food or environment. 

Individual polyethers exhibit varying specificities for cations. Some polyethers have found appHcation as components in ion-selective electrodes for use in clinical medicine or in laboratory studies involving transport studies or measurement of transmembrane electrical potential (4). The methyl ester of monensin [28636-21 -7] i2ls been incorporated into a membrane sHde assembly used for the assay of semm sodium (see Biosensors) (5). Studies directed toward the design of a lithium selective electrode resulted in the synthesis of a derivative of monensin lactone that is highly specific for lithium (6). 

In one biosensor design, the chem preceptive nerve fibers of the anteimules of the blue crab Callinectes sapidus are coimected to a micropipet electrode. This assembly has been termed a receptrode (2). The receptrode created from Callinectes sapidus responds to the presence of amino acids (1) (qv) in concentrations as low as 10 M. 

Biosensors ai e widely used to the detection of hazardous contaminants in foodstuffs, soil and fresh waters. Due to high sensitivity, simple design, low cost and real-time measurement mode biosensors ai e considered as an alternative to conventional analytical techniques, e.g. GC or HPLC. Although the sensitivity and selectivity of contaminant detection is mainly determined by a biological component, i.e. enzyme or antibodies, the biosensor performance can be efficiently controlled by the optimization of its assembly and working conditions. In this report, the prospects to the improvement of pesticide detection with cholinesterase sensors based on modified screen-printed electrodes are summarized. The following opportunities for the controlled improvement of analytical characteristics of anticholinesterase pesticides ai e discussed ... 

In this work, simple (single-use) biosensors with a layer double stranded (ds) calf thymus DNA attached to the surface of screen-printed carbon electrode assembly have been prepared. The sensor efficiency was significantly improved using nanostructured films like carbon nanotubes, hydroxyapatite and montmorillonite in the polyvinylalcohol matrix. 

The work presented is part of a European project (Biosensors for Effective Environmental Protection BEEP) which is aimed at the assembly and application of Photosystem II (PS II)-based biosensors for large scale environmental screening of specific herbicides and heavy metals. 

Sequence-specific biosensor, 183, 185 Selectivity, 92, 143, 147, 155 Selectivity coefficient, 143 Self-assembled monolayers, 39, 118 Selenium, 85 Sensor, 171 Silver halide, 159 Simulation, 35... 

Chaki NK, Vijayamohanan K. 2002. Self-assembled monolayers as a tunable platform for biosensor applications. Biosens Bioelectron 17 1-12. 

Zhong X, Yuan R, Chai Y, Liu Y, Dai J, Tang D (2005) Glucose biosensor based on self-assembled gold nanoparticles and double-layer 2d-network (3-mercaptopropyl)-trimethoxy-silane polymer onto gold substrate. Sensor Actuator B 104 191-198... 

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