Amperometric glutamate biosensor based on poly(o-phenylenediamine) film electrogenerated onto modified carbon paste electrodes

A glutamate biosensor was developed by electropolymerizing o -phenylenediamine on a dehydrogenase-NAD + modified carbon paste electrode. The amperometric response to glutamate was obtained by means of the electrocatalytic oxidation of the enzymatically produced NADH, at an applied potential close to 0 V (Ag/AgCl). After optimizing carbon paste composition, polymer thickness and operating variables, a linear amperometric response to glutamate was obtained within the concentration range 5·0×10 −6 –7·8×10 −5 M with a detection limit of 3·8×10 −6 M. The biosensor was applied to the determination of glutamate in chicken bouillon cubes. Good accuracy was found with respect to a reference enzymatic spectrophotometric method.