Département de chimie moléculaire

This paper describes a new system for amperometric detn. of dissolved oxygen and its application for the detection of anionic toxic substances, which are known as enzyme inhibitors. This biosensor is based on the co-immobilization of laccase from Trametes versicolor and a redox active layered double hydroxide [Zn-Cr-ABTS] on a glassy carbon electrode. The electrochem. transduction step corresponds to the electrocatalytic redn. of O2 at 0.2 V by laccase as catalyst and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) as mediator. Such device provides a fast and a sensitive response for dissolved oxygen detn. between 6 × 10-8 and 4 × 10-6 M and very low detection limits for azide (5.5 nM), fluoride (6.9 nM) and cyanide (6.2 nM). [on SciFinder(R)]