Bioelectrochemical studies on catalase modified glassy carbon paste electrodes

The enzyme catalase (EC: 1.11.1.6) has been covalently coupled onto the surface of glassy carbon (GC) powder matrix using a 16 atom spacer arm. The enzyme coupled powder was made into a paste electrode that was used to study the electrochemical properties. Standard electrochemical techniques like cyclic voltammetry, differential pulse voltammetry and flow injection analysis studies were carried out using this paste electrode. The cyclic voltammogram of the modified paste exhibited a clear increase in the reduction peak at - 180 mV in the presence of hydrogen peroxide. The potential at which maximum Faradaic activity was observed was determined using differential pulse voltammetry, which showed a clear peak at - 100 mV. This potential was used to monitor the response of the electrode to varying substrate concentrations using a home made setup for flow injection analysis. A linear increase in the current values in the range 0.1-1 mM hydrogen peroxide concentration was observed in our system. (C) 2002 Elsevier Science B.V. All rights reserved.