Optical characterization of small-molecule-protein conjugates for development of express high-sensitive immunosensors based on magnetic biolabels

Currently, one of the most dangerous mycotoxin for humans and animals is ochratoxin A (OTA). Despite significant progress in modern approaches for detection of low molecular weight compounds, express methods for on-site sensitive quantification of OTA in food are still to be developed. Conjugates of OTA with a carrier protein - bovine serum albumin - were characterized in terms of kinetics of their interaction with monoclonal antibodies against OTA. Spectral interferometric methods were used for label-free characterization in a real-time mode. An express sensitive method was developed for on-site OTA detection in food based on the use of the characterized OTA-BSA conjugates combined with highly sensitive electronic registration of magnetic biolabels at combinatorial frequencies.