Evanescent wave biosensor

Schuck P 1996 Kinetics of iigand binding to receptors immobiiized in a poiymer matrix, as detected with an evanescent wave biosensor, i. A computer simuiation of the influence of mass transport Biophys. J. 70 1230-49... 

Demarco D.R., Lim D.V., Detection of Escherichia coli 0157 H7 in 10-and 25-gram ground beef samples with an evanescent-wave biosensor with silica and polystyrene waveguides, J. Food Protect. 2002 65 596-602. 

Love WF, Button LJ, Slovacek RE (1991) Optical characteristics of fiberoptic evanescent wave biosensors theory and experiment. In Wise LB, Wingard DL (eds) Biosensors with fiberoptics. Humana, New Jersey, pp 139-180... 

Although an evanescent wave biosensor can be explained in a simple way, a range of complex physical phenomena underlies this apparent simplicity. 

Fig. 5.3. The basic response curve in real time for any evanescent wave biosensor.

An evanescent wave biosensor was devised for determination of analytes capable of intercalation in dsDNA in a FIA system. A polyethylene lensed optical fiber is coated with a thin polymeric layer containing dsDNA which is immobilized there. The fiber is placed in a FLA system immersed in a solution of ethidium bromide (144), which undergoes intercalation in the dsDNA. The fluorescence signal of 144 is thus enhanced about a 1000-fold relative to the evanescent wave fluorescence measurement without the coating and is dependent on the concentration in solution. If an analyte is present in the same solution, it competes with 144 for intercalation in the DNA and causes fluorescence quenching, which can be measured and correlated to the analyte concentration. This method was applied to determination of various analytes, including 4, 6-diamidino-2-phenylindole dihydrochloride (145)247. 

Hutchinson, A.M. (1995) Evanescent-wave biosensors-real-time analysis of biomelocular interactions. Molecular Biotechnology, 3 (1), 47-54. 

Graham. C.R.. Leslie. D.. and Squirrell, D.J., 1992. Gene probe assays on a fiberoptic evanescent wave biosensor. Biosensors Bioelectronics, 7, pp. 487-493. 

Anderson G P, Golden J P and Ligler F S 1994 An evanescent wave biosensor— Part 1 Fluorescent signal acquisition from step-etched fiber optic probes IEEE Trans. Biomed. Eng. 41 578-84... 

Golden J.P., Anderson G.P., Rabbany S.Y. et al. 1994. An evanescent wave biosensor Part II. Fluorescent signal acquisition from tapered fiber optic probes. IEEE Trans. Biomed. Eng. 41 585. 

Demonstration of immunospecificity and optimization of the assay for development of evanescent wave biosensors entails several steps. The choice of a fluorescently labeled Ag typically requires the evaluation of the binding characteristics of several tracers which are structurally related to the antigen. This allows the optimal choice of a fluorescent tracer. In the case of evanescent biosensors, the fluorescently labeled antigen tracer must bind to the antibody with sufficient affinity so that a relatively low concentration (e.g., 1 to 100 nM) will yield a reproducible signal, yet show a relatively low affinity as compared to the target analyte to be measured. 

R. B. Thompson. F. S. Ligler Chemistry and Technology of Evanescent Wave Biosensors. in D, L. Wise, L. B. Wingard (eds,) Biosensors with Fiber-optics, Humana Press, Clifton. N.J., 1991. 

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