Development of microformat imaging microplate and membrane immunoenzyme assays of the herbicide atrazine

A microformat imaging technique in combination with registration of chemiluminescence by a charge-coupled device, CCD camera, were applied for the detection of the herbicide atrazine by two immunoenzyme assay formats - microplate and membrane assays. For the microplate (ELISA) case the detection limit was 95 pg mL(-1), giving a 9.5-fold enhancement in comparison with a traditional colorimetric assay. The membrane dot blot assay allowed detection of up to 40 pg mL(-1) of atrazine (4.5-fold enhancement). Due to the application of polyelectrolyte carriers for rapid reactants separation the membrane assay may be realized in 15 min. CCD-based registration of signals assures a high reproducibility of measurements; the variation coefficient is in the range 1-7%. The effectiveness of the assays developed for controlling triazine herbicides in mineral and tap water has been demonstrated.