Prussian Blue- and lactate oxidase-based amperometric biosensor for lacticacid

The properties of amperometric lactate biosensors based on Prussian Blue (P B) and lactate oxidases (LOX) of different origin (from Pediococcus sp. and Enterococcus sp. RL1) immobilised in Nafion were investigated by flow inje ction analysis. The operating potential was -50 mV (versus Ag/AgCl, 0.1 M K Cl). A linear range in the dependence of current response upon the concentr ation of lactic acid was up to 0.8 mM. The detection limit of electrodes co ntaining a high amount (6 U) of enzyme was below 1 muM. Operational stabili ty could be maintained by exposing the electrodes to low (20 muM) concentra tions of lactic acid. (C) 2001 Elsevier Science B.V. All rights reserved.