Highly Sensitive Detection of Bensulfuron-methyl by Time-Resolved Fluoroimmunoassay Using a Tetradentate β-Diketonate Europium Chelate as a Label

摘要

A tetradentate β-diketonate europium fluorescent chelate, 4,4′-bis(1″,1″,1″,2″,2″,3″,3″-heptafluoro-4″,6″-hexanedion-6″-yl)-chlorosulfo-o-terphenyl (BHHCT)-Eu3+, was used as a label for highly sensitive time-resolved fluoroimmunoassay of bensulfuron-methyl (BSM). A BSM-BSA (BSA=bovine serum albumin) conjugate was labeled with BHHCT-Eu3+ and the labeled BSM-BSA conjugate was used for competitive immunoassay. The assay was carried out in a 96-well microtiter plate coated with the anti-BSM monoclonal antibody. The method gives the detection limit of 24 pg/ml, which is one to two orders of magnitude lower than those of the conventional HPLC and other methods. The RSD of the present method is less than 10%, and the recovery is in the range of 90 - 110% for BSM water samples.