Electrochemical Detection of Lipopolysaccharide using Enzyme-Modified Electrodes

摘要

An enzyme-modified electrode with a chemically amplified response for ferrocenylboronic acid (FcB) derivative was constructed from a gold electrode and a layer containing immobilized diaphorase (Dp). FcB is oxidized on the electrode but regenerated through the Dp-catalyzed reaction in the presence of NADH. The electrooxidation/regeneration cycle for FcB resulted in an amplified electrode response. The enzyme-modified electrode was applied to the highly sensitive measurement of lipopolysaccharide (LPS). The current for FcB decreased in association with its complexation with LPS, and the current response caused by LPS was also amplified through the recycling processes. The detection limit of LPS (from Escherricchia coli 0111 :B4) was as low as 500 ng/ml.