Immunosensors fiber-optical

Fiber Optic Affinity Sensors, Immunosensors and Gene Sensors... 

Bluenstein B., Walczak I., Chen S.Y., Fiber-optic evanescent-wave immunosensors for medical diagnostics, Trends Biotechnol 1990 161-168. 

A fiber optic immunosensor (FOI) has also been reported for detection of PCBs in Aroclors [204]. The quartz fiber surface is coated with PAbs against PCBs and the competitive assay takes place using as fluorescent tracer, an analog of the analyte coupled to 2,4,5-trichlorophenoxybutyrate (TCPB) on the Ab-coated fiber. The LOD achieved is around 10 pg L L... 

The data shown here demonstrate the use of an NIR dye immobilized in a polymer matrix which is sensitive to changes in metal ion concentration and solution pH. Additionally, the utility of NIR dyes in immunosensors has been shown. Although the use of NIR dyes in fiber optic techniques has only recently been demonstrated, the range of potential applications is abundant. As functionalized NIR dyes become commercially available or new, large-scale syntheses are reported, the use of NIR dyes in bioanalytical applications will most certainly expand. 

F. V. Bright, T. A. Betts, and K. S. Litwiler, Regenerable fiber-optic-based immunosensor, Anal. Chem. 62, 1065-1069 (1990). 

M. Daneshvar, G. A. Casay, M. Lipowska, G. Patonay, and L. Strekowski, Investigation of a near-infrared fiber-optic immunosensor, SPIE—The International Society for Optical Engineering Chemical, Biochemical, and Environmental Fiber Sensors V 2063, 128-138(1993). 

A reversible, direct fluoroimmunosensor for human serum albumin (HS A) measurement has been described by Bright et al.(m> Antibody Fab fragments are first immobilized on small quartz plates by hinge-region thiols, and then dansylated. The immunosensor is formed by attaching the quartz plates with bound Fab to the distal end of a bifurcated fiber-optic probe, which transmits both the excitation and emission. Binding of ffSA to the immunosensor results in a three- to five-fold enhancement of dansyl fluorescence. The sensor can be reused up to 50 times, with a detection limit of about 1.8 x 10-8 M, and a somewhat limited dynamic range. 

An evanescent wave fiber optic immunosensor has been used for the detection of ricin in river water.(131) A tapered fiber optic waveguide with covalently bound anti-ricin IgG is used in a sandwich format, with tetramethylrhodamine-labeled antibody as tracer. In a two-step format, ricin in the sample is bound to the fiber first, and then the fiber is exposed to the tracer antibody. Sensitivity is 1 ng/ml for the two-step assay. The one-step assay, in which the fiber optic probe contacts the sample and labeled antibody simultaneously is less sensitive, but more convenient. 

J. R. Astles and W. G. Miller, Reversible fiber-optic immunosensor measurements, Sensors and... 

Geng, T., Morgan, M. T., and Bhunia, A. K. (2004). Detection of low levels of Listeria monocytogenes cells by using a fiber-optic immunosensor. Appl. Environ. Microbiol. 70, 6138-6146. 

Zhou, C. H., Pivarnik, P., Auger, S., Rand, A., and Letcher, S. (1997). A compact fiber-optic immunosensor for Salmonella based on evanescent wave excitation. Sens. Actuators B Chem. 42,169-175. 

Aroclor 1242 Fiber optic immunosensor Soil, river, and bay water 10 pg L1 107... 

Zhao, C.Q., N.A. Anis, K.R. Rogers, et al. 1995. Fiber optic immunosensor for polychlorinated biphenyls. J. Agric. Food Chem. 43 2308-2315. 

Many types of fiber optic or other optical waveguide have been used for immunosensors employing both single-fiber and bifurcated designs. The light... 

Although this method makes any washing steps superfluous, it is difficult to apply it in vivo because of the need for labelled antigens. Vo-Dinh and co-worker have described a portable fiber-optic monitor for use in combination with enzyme-linked immunosorbent assay [86] and a fiber-optic immunosensor for benzo[a]pyrene [101]. 

Vo-Dinh, T., Griffin, G. D., Sepaniak, M. J., Fiber Optic Immunosensors , in Fiber Optic Chemical Sensors and Biosensors, Wolfbeis, O. S. (ed.) Boca Raton, FL CRC Press, 1991, Chap. 18. 

Okadaic acid toxin Indirect competitive immunosensor using fiber-optic transduction with flow injection analysis 0.1 pgl" Mussel homogenates 20 minutes [147]... 

Immunochromatography, colloidal gold, silver enhancement 10 minutes Evanescent wave fiber-optic immunosensor Colorimetric and chemiluminescence ELISA Immunochromatography, colloidal gold, silver enhancement 10 minutes Sandwich hybrid receptor-immunoassay,... 

Fluororescently labeled toxin captured and immobilized on the surface of the optical waveguide GMl 20 minutes Magnetoelastic immunosensor Piezoelectric immunosensor Wavelength modulation-based SPR biosensor Fiber optic surface plasmon resonance ... 

Figure 34. A fiber-optical immunosensor, in which labeled antibody molecules are gradually replaced by free analytes, causing the fluorescence signal to decrease a) Core b) Region of evanescent wave Fixed analyte O Free analyte ...

Among direct immunosensors the most favored are optical sensors, because they incorporate the advantages of fiber optics or optoelectronic transducers. The nonelectrical properties of optical systems offer important safety advantages for... 

First immunosensor Ovalbumin on a platinum wire First fiber-optic pH sensor for in vivo blood gases First fiber-optic-based biosensor for glucose First surface plasmon resonance (SPR) immunosensor First mediated amperometric biosensor for the detection of glucose Launch of the MediSense ExacTech blood glucose biosensor SPR-based biosensor system i-STAT launches hand-held blood analyzer Glucocard launched... 

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