Detection of polychlorinated biphenyls (PCBs) in milk using a disposable immunomagnetic electrochemical sensor

PCBs are among the most persistent and widely distributed pollutants in the global ecosystem and therefore it is of great importance for both human and environmental health to develop practical analytical systems to detect them. In this context, this work presents the application of an electrochemical immunosensor based on Screen-Printed Carbon-based Electrodes as transducers with antibody-coated magnetic microparticles as a solid phase. The immunoassay was based on direct competition between the analyte present in the samples and an alkaline phosphatase-labeled tracer. The product of the enzymatic reaction between AP and its substrate (alpha-naphthyl phosphate) was detected using differential pulse voltammetry. Sample extraction and clean-up was achieved using Solid Phase Extraction. Detection of low concentrations PCB was achieved and the method was shown to be applicable to both skimmed and whole milk. SPE was shown to improve the analysis.