Methylene‐green‐mediated carbon paste glucose biosensor

Abstract

Abstract An amperometric glucose bioelectrode based on the incorporation of methylene green (MG) within a glucose oxidase (GOD)‐containing carbon paste is described. The electrode generates an anodic current in the range of 0.0–0.6 V (vs. SCE). The optimum pH is 8.5. The apparent Michaelis constant for the Cali bration plot is 49.3 m M (at 0.5% MG and 5.0% GOD loadings). The electrode sensitivity is 18.1 μA/m M cm 2 . The electrode is insensitive to paracetamol and ethanol. At 0.068 V the response to ascorbic acid (40 μ M ) accounts for 2.4% of that of the normal physiological glucose level in blood. The performance was optimized by systematically altering the electrode composition and electrode potential. The electrode was used to measure glucose in a serum sample and gave an acceptable correlation with the reference method Eksan‐G results. Good stability was observed for storage in the dry state in the refrigerator.