ELECTROCHEMICAL PLATINIZATION OF RETICULATED VITREOUS CARBON ELECTRODES TO INCREASE BIOSENSOR RESPONSE

Platinized reticulated vltreous carbon (RVC) was used in the construction of an immobilized enzyme, chemically modified electrode suitable for flow injection analysis (FIA) applications. The platinized surface yields an increased current response due to the oxidation of hydrogen peroxide as compared with nonplatinized RVC. it also allows the electrode to operate at a much lower potential (+0.6 vs +0.9 V vs saturated calomel electrode) thus resulting in increased signal to noise. Platinum is electrodeposited on only part of the electrode, allowing enzyme Immobilization directly to the carbonaceous surface. This heterogeneous system offers the advantages of a platinum surface for electrochemical detection and a carbon surface for enzyme immobilization, on the same electrode. The activity of the glucose oxidase Immobilized on the platinized electrode is very similar to that of the nonplatinized electrode. The linear range of the electrode is 0–50 mM glucose using a 5-μl. sample volume. © 1990, American Chemical Society. All rights reserved.