Pesticide determination in tap water and juice samples using disposable amperometric biosensors made using thick-film technology

A new design of biosensor strips for pesticide analysis is presented. The developed biosensors integrate a photolithographic conducting copper track, graphite¯epoxy composite applied by screen-printing and enzyme (AChE or BChE) immobilised manually by crosslinking with glutaraldehyde. Detection limits in the order of 10-10 to 10-11 M pesticides (paraoxon and carbofuran) have been achieved in standard solutions. Pesticide analysis have been realised on spiked real samples of tap water and fruit juice, with recovering percentages close to 100%, corroborating that the biosensor is sensitive enough to detect pesticides in these matrices.