Rapid biorecognition assay for herbicides in biological matrices

A rapid assay capable of detecting several commonly used herbicides at nanogram per milliliter concentrations in biological fluids is described. The assay is based on inhibition of photosynthetic electron transport in spinach thylakoids by the target compounds with colorimetric detection using a redox dye. Using a microtiter plate format, high throughput assays of water, urine, and homogenized tissue were performed in minutes with minimal sample preparation. Detection limits of 3 ng/mL for atrazine, 3 ng/mL for diuron, and 1 ng/mL for terbutryn were observed.