Enzyme electrode for the measurement of lactate in undiluted blood

An enzyme electrode is described based upon the enzyme lactate oxidase (EC 1.1.3.2) coupled to an H2O2 sensor. Use of an organosilane-treated microporous membrane over the enzyme layer, allows responses linear to 18 mmol/l L-lactate with response times of 1-3 min, whilst giving independence from stirring. The method is suitable for the bedside analysis of a single drop of undiluted whole blood. Correlation with a routine method gave y = 0.96x + 0.11, r = 0.996, n = 46.