Chemically modified reticulated vitreous carbon electrode with immobilized enzyme as a detector in flow-injection determination of glucose

The construction and response of a chemically modified electrode in which glucose oxidase (E.C. 1.1.3.4) is covalently attached to the surface of reticulated vitreous carbon is reported. Hydrogen peroxide produced by the oxidation of glucose is consumed at the electrode suface, which is held at + 0.9 V vs. a saturated calomel reference electrode. The hydrodynamic and electrochemical properties of the reticulated vitreous carbon electrode substrate make the electrode attractive for use in flow systems. The current varies nonlinearly with glucose concentration throughout most of the range examined (10^?1?10^?4 M). At concentrations of 2.5–10 mM, response is approximately linear with concentration, with a sensitivity of about 400 nA mM^?1. Relative standard deviation for five sample at 10 mM^?1 is less than 2%.