A LACTOPEROXIDASE-BASED FLOW-INJECTION AMPEROMETRIC BIOSENSOR FOR IODIDE DETECTION

The following contains work carried out into the preparation of an amp erometric enzymatic biosensor (M.P. Byfield, R.A. Abuknesha, Biochemic al aspects of biosensors. Biosens. Bioelectron. 9 (1994) 373-400; C.R. Lowe, An introduction to the concepts and technology of biosensors. B iosensors 1 (1985) 3-16; J.S. Schultz, Biosensors. Sci. Am. 8 1991 48- 55) using the enzyme, lactoperoxidase (LPOD), for the detection of iod ide. In this paper, a study of two major avenues which were undertaken to achieve an iodide biosensor, using electrochemical transduction te chniques, are discussed. The first of these focuses on the use of LPOD in solution using both DPBS and acetate buffers, while later work has concentrated on investigations into the immobilised enzyme. The forme r has been shown to measure iodide concentrations of less than 0.1 mu mol/l while the latter can be used to detect iodide levels lower than 10 mu mol/l. The difficulties and drawbacks associated with both these systems are discussed. (C) 1998 Elsevier Science S.A. All rights rese rved.