AMPEROMETRIC GLUTAMATE BIOSENSOR BASED ON POLY(O-PHENYLENEDIAMINE) FILM ELECTROGENERATED ONTO MODIFIED CARBON-PASTE ELECTRODES

A glutamate biosensor was developed by electropolymerizing o-phenylene diamine on a dehydrogenase-NAD(+) modified carbon paste electrode. The amperometric response to glutamate was obtained by means of the elect rocatalytic oxidation of the enzymatically produced NADH, at an applie d potential close to OV (Ag/AgCl). After optimizing carbon paste compo sition, polymer thickness and operating variables, a linear amperometr ic response to glutamate was obtained within the concentration range 5 .0 x 10(-6)-7.8 x 10(-5) M with a detection limit of 3.8 x 10(-6) M. T he biosensor was applied to the determination of glutamate in chicken bouillon cubes. Good accuracy was found with respect to a reference en zymatic spectrophotometric method. (C) 1997 Elsevier Science Limited.