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

A carbon paste‐poly(o‐phenylendiamine)‐modified electrode to be 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 electrochemically 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.