Amperometric biosensor for the detection of hydrogen peroxide using catalase modified electrodes in polyacrylamide

A simple biosensor for the detection of hydrogen peroxide in organic solvents has been do,eloped and Coupled to a flow injection analysis (FIA) system. Catalase was entrapped in polyacrylamide gel anti placed oil the surface of platinum (working electrode) fixed in a Teflon holder with Ag-wire (auxiliary electrode), followed by addition of filter paper soaked in KCl. The entrapped catalase gel was held on the electrode using membrane. The effects of cellulose and polytetrafluroethylene (PTFE) membranes on the electrode response towards hydrogen peroxide have been studied, The modified electrode has been used to study the detection of hydrogen peroxide insolvents like water, dimethyl sulfoxide (DMSO). and 1,4-dioxane using amperometric techniques like cyclic voltammetry (CV) and FIA. The CV of modified catalase electrode showed a broad oxidation peak at -150mV and a clear reduction peak at -212mV in the presence of hydrogen peroxide. Comparison of CV with hydrogen peroxide in various solvents has been carried out. The electrode showed an irreversible kinetic with DMSO its the solvent. A flow cell has been designed in order to carry on FIA studies to obtain calibration plots for hydrogen peroxide with the modified electrode. The calibration plots in several solvents such as water. dimethyl sulfoxide, 1,4-dioxane have been obtained. The throughput of the enzyme electrode was 10 injections per hour. Due to the presence of membrane the response time of the electrode is concentration dependent. (c) 2005 Elsevier B.V. All rights reserved