New direct optical biosensors for multi-analyte detection

A new label-free optical biosensing method has been developed, which can be called Spectral Correlation Method (SCM). The method is based on measurements of a correlation signal of two interferometers in an original optical scheme. The first interferometer is a scanned Fabry–Perot interferometer, in which the distance between two mirrors is periodically changed by a peizoelectric driver. The second interferometer is formed by a biochip, which is a simple glass plate with thickness of several tens or hundreds microns with different recognition spots or wells, or flow channels. In our experiments, a microscope cover glass was successfully used as a biochip to detect reactions of binding or detachment of different biological agents in real time. Two- and 96-channel SCM devices have been designed to register bio- and chemical-components in real time. The sensogram drifts for these devices expressed in terms of layer thickness were 20 and 40 pm/h, respectively.