Immunosensors, fluorescence applications

The applications of visible fluorescent immunosensors described are all susceptible to large interferences from biomolecules such as bilirubin and porphyrins. A more comprehensive review of immunosensors has been published by Robinson.(10S) The spectral interferences associated with visible fluorophores have prompted the design of an NIR optical immunosensor techniques with high sensitivity and low interference. 

Some of the inherent difficulties associated with the use of this fluorescence-based immunosensor include fiber to fiber variability in the signal, cost of the instrument as well as fibers, and availability of portable commercial instrument. Still, further characterization of the instrument and the methods surrounding the immunoassay are necessary in order to increase its potential application as a sophisticated analytical technique. Relevant to the detection of botulinum neurotoxins, binding in a variety of biological and environmental matrices needs to be investigated. Also, to increase the applicability of the biosensor as a technique that offers reliable quantitative results, a method for internal standardization should be investigated. The fiberoptic immunosensor in its present state is best described as a technique that allows for the selective detection and monitoring of botulinum neurotoxins at concentrations at or above 300 pg/mL. However, this technique would provide only semi-quantitative results as far as the determination of unknown concentration of the toxin is concerned. 

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