AN IMMUNOSENSOR FOR THE AUTOMATIC-DETERMINATION OF THE ANTIFOULING AGENT IRGAROL-1051 IN NATURAL-WATERS

The development of an immunosensor for analysis of the antifouling age nt Irgarol 1051 hio-4-tert-butylamin-6-cyclopropylamin-s-triazine) is described. The immunosensor is based on a heterogeneous competitive en zyme immunoassay and uses binder azlactone support with immobilized pr otein A/G. The flow-through immunosensor is completely automated and i s able to carry out a whole analysis cycle in about 23 min. Competitiv e calibration curves have an I-50 value of 0.053 mu g/L (0.21 nM), wit h a limit of detection of 0.010 mu g/L and a quantification dynamic ra nge from 0.019 to 0.158 mu g/L. The protein A/G support can be used fo r more than 600 assay cycles without loss Of sensor performance. The s ensor is prone to some interferences from tert-butyl-containing s-tria zine compounds, such as terbutryn and terbumeton, bur little inteferen ce is shown for other s-triazine compounds, e.g., atrazine or simazine . The developed sensor is applied to the determination of trace levels of Irgarol 1051 in water samples such as Mediterranean marina and bea ch seawater, estuarine river water, and lake water, without any sample pretreatment other than adjusting the pH and ionic strength of sample s to those of standards. Good correlation is achieved between the immu nosensor results and ELISA or HPLC analyses.