Photothermal bioanalytical methods for pesticide toxicity testing.

This paper describes bioanalytical methods and biosensors which rely on cholinesterase (ChE) inhibition and can be used to detect and test the toxicity of organophosphate (OP) and carbamate pesticides. Particular attention is given to the combined use of these methods and photothermal detection that has recently led to improved sensitivity and increased sample throughput of ChE bioanalytical assay. Following a rapid and simple sample preparation procedure, this assay can detect organophosphate pesticides such as paraoxon in the sub ng/mL concentration range. The AChE bioanalytical method demonstrated different sensitivity to various pesticides, which correlated well with pesticide toxicity expressed as LD50 for rats. Similarly, the same pesticide yielded different ChE inhibition in different organisms. This opens the possibility of applying these bioanalytical methods to evaluate the acute toxicity of OP compounds or of environmental samples to particular organisms.