Analytical Sciences


Abstract − Analytical Sciences, 15(2), 135 (1999).

Potentiometric Determination of NAD(P)H Coenzymes Using a Nitrite-Selective Membrane Electrode and a Nitrate Reductase Enzyme and the Application to Glucose Assay in Human Serum
Takashi KATSU *, Takeshi HASHIMOTO and Shima HIRAMAKI
Faculty of Pharmaceutical Sciences, Okayama University, Tsushima, Okayama 700-8530, Japan
NAD(P)H coenzyme concentrations were determined with the combination of a nitrite-selective membrane electrode and a nitrate reductase enzyme. The method was based on the detection of nitrite formed by the enzymatic reaction of NAD(P)H with nitrate catalyzed by nitrate reductase. The lower detection limits for both these coenzymes were around 100 mM. This system was applied to detect glucose by combining an additional glucose dehydrogenase enzyme. Serum (Keywords: Enzymatic method, nitrite-selective membrane electrode, nitrate reductase, NAD(P)H determination, serum glucose assay, coupled enzyme reactions)