Article ID Journal Published Year Pages File Type
751541 Sensors and Actuators B: Chemical 2007 4 Pages PDF
Abstract

A bienzyme-based Clark electrode was developed for the interference-free determination of l-glutamate. This sensor is based on the specific dehydrogenation by l-glutamate dehydrogenase (GLDH, EC 1.4.1.3) in combination with p-hydroxybenzoate hydroxylase (HBH, EC 1.14.13.2). The enzymes were entrapped by a poly(carbamoyl) sulfonate hydrogel on a Teflon membrane. The principle of the determination scheme is as follows: the specific detecting enzyme, GLDH, catalyses the specific dehydrogenation of l-glutamate consuming NADP+. The product, NADPH, initiates the irreversible hydroxylation of p-hydroxybenzoate by HBH in the presence of oxygen. This results in a detectable signal due to the HBH-enzymatic consumptions of dissolved oxygen in the measurement of l-glutamate. The sensor has a fast steady-state measuring time of 20 s with a quick response (2 s) and a short recovery (1 min). It shows a linear detection range between 10 μM and 1.5 mM l-glutamate and a detection limit of 5 μM. A Teflon membrane, which is used to fabricate the sensor, makes the determination to avoid interferences from different amino acids and electroactive substances.

Related Topics
Physical Sciences and Engineering Chemistry Analytical Chemistry
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