In situ optical biosensing system and method for monitoring serotypes

Abstract

A label-free optical biosensing system and method provide high sensitivity and specificity for in situ detection and activity estimation of serotypes, such as Botulinum Neurotoxins (BoNT). Pre-fabricated thin-film support structures are treated with a competitive immunoassay coupled to a biochemical cascade reaction, which provides optical signal amplification. When the thin-film support structures receive a target analyte and are exposed to polychromatic light, reaction products cause a change in average refractive index which appears in reflectivity spectra measured by an optical interferometer. Optical signal amplification enables a linear response for serotype concentrations of only a few picograms per millilitre, as well as a level-of-detection threshold of 5.0 picograms per millilitre or less. The specificity and selectivity of the method have been verified in studies using various combinations of different serotypes as a target analyte. Similarly, the serotype activity is estimated by an adjunct sensing platform.

Dependencies are inferred from the claim text.