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Proceedings Paper

Validation of an optical immunoprobe for pesticide detection in natural water samples
Author(s): Gerd Lang; Andreas Brecht; Laurence Amalric; Christophe Mouvet; Guenter Gauglitz
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Paper Abstract

Immunoanalytical techniques represent one of the most important applications of biomolecules in analytical procedures. Direct monitoring of immunoreactions by a device is a particular attractive approach to environmental sensing as it offers speed, a simple test scheme, and does not require labelled compounds. Target limits of detection for pesticides are imposed by the EU drinking water act (0.1 (mu) g/1 for a single pesticide). A competitive test format with surface immobilized antigen is common for pesticide detection with direct immunosensors. Free pesticide binds to antibody in solution decreasing the amount of antibody binding to the transducer. A prototype atrazine sensor based on reflectrometric interference spectroscopy was investigated. The slope of the binding curve was used to measure the pesticide concentration by comparison with a calibration curve. By sophisticated surface modification techniques and protolytic regeneration of the surface with an enzyme we were able to use a single chip for more that one hundred measurements without significant loss of binding efficiency. Using a flow injection system a test cycle including measurement and regeneration is done within fifteen minutes. Using on-line evaluation the result is achieved five minutes after the measurement was started. Atrazine concentrations in the lower and sub-ppb range were measured in natural water samples in France. Using HPLC as a reference method, the correlation coefficients between the two analytical techniques were investigated.

Paper Details

Date Published: 29 September 1995
PDF: 7 pages
Proc. SPIE 2508, Chemical, Biochemical, and Environmental Fiber Sensors VII, (29 September 1995); doi: 10.1117/12.221759
Show Author Affiliations
Gerd Lang, Univ. Tuebingen (Germany)
Andreas Brecht, Univ. Tuebingen (Germany)
Laurence Amalric, BRGM (France)
Christophe Mouvet, BRGM (France)
Guenter Gauglitz, Univ. Tuebingen (Germany)

Published in SPIE Proceedings Vol. 2508:
Chemical, Biochemical, and Environmental Fiber Sensors VII
Annamaria V. Scheggi, Editor(s)

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