Immunosensors for pesticide determination in natural waters

The development and application of immunosensors for environmental monitoring has grown steadily in recent years. In this review, immunosensors developed in the last few years are highlighted regarding their importance and practical contribution to environmental analysis with particular emphasis on monitoring of pesticide levels. Different transduction elements and mechanisms used for the detection of the physicochemical change(s) produced by the biological interaction are shown, as well as their application to the development of real-time measurement devices or systems. In addition, examples concerning the analysis of pesticides in natural water samples obtained using a recently developed optical immunosensor are given. Validation of immunosensor measurements with conventional chromatographic techniques is also reported. The immunosensor system detection mechanism is based on a solid-phase fluoroimmunoassay combined with an optical transducer chip chemically modified with an analyte derivative. Applications to the analysis of atrazine, simazine, paraquat, alachlor, 2,4-D and isoproturon in water are also reviewed. (C)2001 Elsevier Science B.V. All rights reserved.