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Preparation of antibodies and development of a sensitive immunoassay with fluorescence detection for triazine herbicides.

Authors :
Herranz S
Ramón-Azcón J
Benito-Peña E
Marazuela MD
Marco MP
Moreno-Bondi MC
Source :
Analytical and bioanalytical chemistry [Anal Bioanal Chem] 2008 Jul; Vol. 391 (5), pp. 1801-12. Date of Electronic Publication: 2008 Feb 23.
Publication Year :
2008

Abstract

Specific polyclonal antibodies against s-triazine herbicides were obtained by preparing immunogens coupling home-synthesized haptens derivatives of simazine (6-chloro-N-ethyl-N'-ethyl-1,3,5-triazine-2,4-diamine) to lysine groups of hemocyanin from keyhole limpets and bovine serum albumin carrier proteins. Three highly sensitive rabbit antisera were obtained and evaluated with a battery of six enzyme tracers derived from triazine structures in an optimized ELISA format. The antiserum As8 and the HRP-2f tracer, which yield the best assay sensitivity for simazine (detection limit 0.11 +/- 0.02 microg L(-1), IC(50) 0.88 +/- 0.04 microg L(-1)), were applied to the development of a sensitive flow-through immunoassay for the analysis of this herbicide. The automated assay was based on a direct competitive immunosorbent assay and fluorescence detection. The optimized method presents an IC(50) value of 0.35 +/- 0.04 microg L(-1) with a detection limit of 1.3 +/- 0.9 ng L(-1) and a dynamic range from 0.010 to 7.5 microg L(-1) simazine. The generic nature of the antiserum was shown by good relative cross-reactivities with other triazines such as atrazine (420%) or propazine (130%) and a lower response to terbutylazine (6.4%) and desethyl-atrazine (2.2%). No cross-reactivity was obtained for nonrelated pesticides such as 2,4-dichlorophenoxyacetic acid or linuron and the assay could be applied as a screening method for triazine herbicides. The total analysis time was 30 min per determination and the immunosensor could be reused for more than 150 cycles without significant loss of activity. The immunosensor has been successfully applied to the direct analysis of simazine in surface water samples at the nanogram per liter level. The results obtained by comparative analysis of the immunosensor with a chromatographic procedure for triazines showed a close correspondence.

Details

Language :
English
ISSN :
1618-2650
Volume :
391
Issue :
5
Database :
MEDLINE
Journal :
Analytical and bioanalytical chemistry
Publication Type :
Academic Journal
Accession number :
18292992
Full Text :
https://doi.org/10.1007/s00216-008-1895-1