THIN-FILM CONDUCTOMETRIC BIOSENSORS FOR GLUCOSE AND UREA DETERMINATION

The characteristics of the developed conductometric biosensors for ure a and glucose determination are described. Conductometric transducers based on thin-film interdigitated metal (Au, Cr, Cu, Ni) electrodes we re studied, and enzymes urease and glucose oxidase were used for the s elective membranes formation on the chips having gold electrodes. The influence of ionic strength and buffer capacity of the samples on the biosensors response in kinetic and steady-state modes of measurements was thoroughly tested. It was shown that the kinetic response of the s ensors does not depend on the buffer capacity of the analyzed sample. In basic features the performance of the developed biosensors is rathe r close to that of respective enzyme field effect transistor, though t he former are much superior when the technological complexity of the t ransducer itself is considered and taking into account that conductome tric sensors require no reference electrode.