A Four-Channel Electrochemical Immunosensor for Detection of Herbicides Based on Phenoxyalkanoic Acids

An electrochemical immunosensor combining three monoclonal antibodies on the same measuring element produced by screen-printing was constructed for the semiquantitative group-specific detection of herbicides belonging to phenoxyalkanoic acids. The combination of different monoclonal antibodies covalently immobilized on three working electrodes and one additional electrode containing immobilized albumin provided a more reliable detection of phenoxyalkanoic acids. Peroxidase-2,4-dichlorophenoxyacetic acid conjugate was used as a tracer suitable for all the antibodies employed in a competitive immunoassay. Several herbicides were used to characterize the immunosensor. The developed immunosensor was tested on samples of surface water spiked with different herbicides and binary mixtures of herbicides. The proposed approach seems feasible for rapid screening of large series of samples for the presence of herbicides.