Immunoassay for polychlorinated biphenyls (PCB) using screen printed electrodes

A disposable sensor for the detection of polychlorinated biphenyls (PCB) in soil samples has been developed using polyclonal antibodies as recognizing element and carbon-based screen printed electrochemical electrodes as sensing element. The analysis scheme has been based on the competitive enzyme linked immunosorbent assay (ELISA) protocol. The immunochemical reaction has been carried on using an Immobilon™ membrane as the solid phase. The enzyme used for the measurement of the immunoreaction has been alkaline phosphatase whereas the electrochemical substrate was α-naphthyl phosphate. The extent of the immunochemical reaction has been monitored by means of an electrochemical product using screen-printed electrodes and differential pulse voltammetry (DPV). The screen-printed electrodes were characterized and their electrochemical performance tested. Soil samples were assayed using a simple extraction kit. A detection limit of 0.3–0.6 ng/ml in solution was achieved with the proposed method regardless of PCB mixture standard. © 1999 John Wiley & Sons, Inc. Field Analyt Chem Technol 3: 179–184, 1999