ELECTROCHEMICAL POLY(1,3-PHENYLENEDIAMINE) SYNTHESIS AS ENZYME IMMOBILIZATION MEDIA

Electrochemical polymerization of the 1,3-phenylenediamine in the pres ence of glucose oxidase with KCl aqueous electrolyte at a potential of 0.800 V versus Ag-AgCl produces adherent poly(1,3-phenylenediamine) c ontaining enzyme (glucose oxidase) film on a platinum electrode. Polym eric sensor prepared in this one-step procedure can be used to determi ne hydrogen peroxide formed as the result of the enzymatic reaction be tween glucose and glucose oxidase in the presence of O-2. The amperome tric responses of the resultant enzyme electrode to glucose were rapid , reaching steady-state values within 4-5 s, and there was a linear re lationship between glucose concentration and obtained current up to 6 mM. Polymeric sensor was stable for more 3 months. The glucose selecti vity of enzyme electrode was determined in the presence of some interf ering substances, such as lactose, sucrose, urea, uric acid, paracetam ol, and ascorbic acid. Also, the effects of buffer concentration, stor age conditions, and temperature on the steady-state amperometric respo nses were studied. Moreover, the Arrhenius activation energy for the e nzymatic reaction was calculated. (C) 1998 John Wiley & Sons, Inc.