Selectivity biosensor

Barker S.L., Kopelman R., Meyer T.E., Cusanovich M.A., Fiber-Optic Nitric Oxide-Selective Biosensors, Anal. Chem. 1998 70 971. 

K.M. Millan and S.K. Mikkelsen, Sequence-selective biosensor for DNA based on electroactive hybridization indicators, Anal. Chem., 65 (1993) 2317-2323. 

Glutamate Sensors. Glutamate occurs in unusually high concentrations in the brain and has been shown to stimulate neuronal activity (35). The role of this species as a neurotransmitter is not completely understood, however, and there has been a great deal of research aimed at studying its excitatory function in the brain. A selective biosensor for rapid determination of glutamate would be of great importance to neurochemical researchers. 

Despite their advantages of specificity and selectivity, biosensors suffer from a severe disadvantage, the instability of the biological recognition system, which makes storage and operation in harsh chemical environments problematic. This problem has been addressed using a newly developed sensor with injected recognition element biosensors (whose operational principle is based on the one time use... 

Composite biomaterials formed between small molecules (ligands, metals Euid proteins) and DNA capable of generating anal3dical signals have also been used to design selective biosensors [183-185]. In this case, a monolayer of... 

Novel electrode materials have emerged in the last decades as a consequence of new requirements for reliable, sensitive and selective biosensor devices. This paper reviewed the most important materials used for the development of biosensors, biochip and supporting matrices. A summary of the principal electrode materials and methods is presented in Table 7.2. The work focused primarily on the characterization of these materials, the most important techniques used for electrode modification and their applicability for the construction of sensors and biosensors. Cmrent and future trends in material science for biosensors have been also discussed. 

For example, parameters such as transducer type and pretreatment, enzyme and mediator concentration and their rahos within the film, type of immobihzation matrix, immobihzation parameters, and film thickness are varied. A rahonal optimization approach includes that the main parameters affecting the overah ET pathway and hence the final sensor response have to be investigated in order to find reasonable tools for tuning the performance of the selected biosensor design. 

Baker SLR, Kopelman R, Meyer TE, Cusanovich MA (1998) Fiber optic nitric oxide selective biosensors and nanosensors. Anal Chem 70 971-976... 

Artificial BLMs offer opportunities for development of chemically selective biosensors [6,7], The essential idea is that a receptor (such as a protein molecule) which can selectively bind to a specific organic or biochemical species (stimulant or analyte) can be incorporated into an ordered lipid membrane assembly such that selective binding events between receptor and stimulant will lead to alterations of the phase structure or electrostatic fields of the membrane (transduction). These perturbations can be monitored electrochemically as changes of transmembrane ion conductivity or as alterations in membrane capacitance. 

Compared with classical analytical methods such as gas chromatt raphy, HPLC, atomic absorption or mass spectrometry, the detection of pollutants by biosensors is generally less specific. These devices provide valuable information on a class of pollutants rather than a mere information about a specific compound, although the use of mutants that are resistant to specific pollutants can render them more selective. Biosensors provide valuable information about the real biological effects of the pollutants in a sample since phytotoxicity is determined from the measurement of electron transport activity, photocurrent or photosynthetic oxj en evolution. It is important to note that althoi the PSII complex is sensitive to various pollutants (herbicides, heavy metals, sulphites, nitrates, carbonates), its susceptibility to these compounds is highly variable, tanging from nanomolar to milhmolar concentrations. 

Biomacromolecules were exploited as templates in the enzymatic synthesis of electronic and photonic materials for the development of biofunctional complexes and selective biosensors. The aniline was polymerized by the catalysis of HRP on a calf thymus DNA matrix consisting of a synthetic oligonucleotide (poly[dA-dC].poly[dG-dT]) [54]. The complexation of PANI with DNA and the ohgonucleotide was found to induce reversible changes in the secondary structure of the nucleic acid template, leading to the formation of an overwound polymorph. The melting behavior of the PANI/DNA complex demon-... 

---