Fiber-optic immunosensors

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... 

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). 

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. 

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. 

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,... 

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 ...

---