Automated immunosensing system for 3,5,6-trichloro-2-pyridinol: Application to surface water samples Original Research Article

The development of immunosensors for 3,5,6-trichloro-2-pyridinol is presented. The sensors are based on the principles of the direct competitive enzyme-linked immunosorbent assay, and use a specific monoclonal antibody (mAb) raised against the analyte. Immunoreagents are orientedly immobilized on both a derivatized agarose ester and alkylamined controlled-pore glass. Another immunosensor carries out the competition reaction in solution, being the immunocomplexes captured by Protein A/G. The competition is established, in all cases, between the analyte and a hapten conjugated to horseradish peroxidase. Fluorimetric detection is applied. The performance of the three sensors is compared in terms of assay sensitivity and reactor reusability. All the sensors developed are sensitive enough to detect the analyte in the sub-ppb range. Interferences from related compounds are negligible (cross-reactivity less than 1%) except for 2,4,5-trichlorophenol (cross-reactivity 9.28%). The application to the determination of the analyte in tap and lake water samples is discussed.