Screen-printed electrochemical immunosensors for PCB detection

An electrochemical enzyme immunoassay for polychlorinated biphenyls (PCB) u sing carbon-based screen-printed disposable electrodes as the solid-phase f or reagent immobilization and also as the signal transduce has been optimiz ed. Horseradish peroxidase (HRP) was conjugated with Ag or Ab and used as t he enzyme label. Hydrogen peroxide and ferrocenemonocarboxylic acid (FCA) w ere used as substrate and mediator in order to determine the HRP activity i n the range 10(-8)-10(-10)M. Indirect and direct competitive assays for PCB have been presented. The advantage of this approach is the relatively fast analysis time (30 min) in comparison with a lest based on microtiter assay plates (14 h); moreover, the use of disposable screen-printed electrodes e liminates the problems of fouling and surface regeneration of the electroch emical device.