Study of biochemical reactions in thin organic films by means of evanescent optical wave

An optical biosensor has been developed for detection of pesticides, based on the evanescent optical wave technique. The concentration of the pesticide was measured in liquid. We specially originated a core complex of photosystem II film on a cheap disposable element. A setup on the basis of the Kretschmann arrangement was improved by using a computer-controlled angular scanning system. The detection concentration limits were 10−11 M for dinitrophenole and 10−10 M for paraoxon. The results obtained show the perspective of the integral method for detection of different kinds of pesticides at extremely low concentration levels of 0.1 ppb.