Chloroperoxidase Modified Electrode for Amperometric Determination of 2,4,6-Trichlorophenol

摘要

A carbon paste-poly(o-phenylendiamine)-modified electrode to he used as amperometric biosensor for 2.4.6_trichlorophenol (TCP) is described. The enzyme chloroperoxidase (EC 1.11.1.10) from Caldariomyces fumago is immobilized through dispersion in a graphite paraffin oil carbon paste covered by an electrogenerated poly(o_phenylendiamine) (PPD) layer. The main enzymatic dehalogenation product, 2,6-dichloro-1,4-benzoquinone (DCQ) is characterized by liquid chromatography-mass spectrometry and cyclic voltammetry. This product is electrochemi_cally active and can be detected amperometrically at + 150 mV vs. Ag AgCl KCl (3 M). The biosensor exhibits a response time of 4 min, a detection limit of 10~(-7) M, and a dynamic linear range between 10~(-7) and 10~(-6) M. Selectivity as well as operating and storage stability were evaluated.