Biosensors based on enzyme inhibition: Detection of organophosphorus and carbamate insecticides and dithiocarbamate fungicides

The dithiocarbamate fungicides and the organophosphorus and carbamate insecticides are two families of pesticides of environmental concern used on a very large scale worldwide. The need for increasing numbers of analyses has created a demand for the development of rapid, simple, and low cost methods. Enzyme sensors based on the abilities of these compounds to inhibit enzymes are described. An enzyme sensor with immobilized aldehyde dehydrogenase is described allowing the detection of 9 ppb of zineb, whereas the classical method allows the determination of 400 ppb. Using screen-printed electrodes with acetylcholinesterase, it is possible to detect 0.5 ppb of paraoxon in aqueous buffer and 1.4 ppb of paraoxon in a mixture of hexane and water (80/20). © 1999 John Wiley & Sons, Inc. Field Analyt Chem Technol 3: 171–178, 1999