A disposable multielectrode biosensor for rapid simultaneous detection of the insecticides paraoxon and carbofuran at high resolution Original Research Article

A sensitive screen-printed amperometric multielectrode biosensor for the rapid discrimination of the insecticides paraoxon and carbofuran in mixtures was developed. It was based on the principle of acetylcholinesterase (AChE) inhibition and chemometric data analysis using artificial neural networks (ANNs). Four types of native or recombinant AChEs (electric eel, bovine erythrocytes, rat brain, Drosophila melanogaster) were immobilised by screen printing on four-electrode thickfilm sensors in sets containing each AChE. The multisensors were used for quantitative inhibition analysis of binary reagent mixtures combining the AChE-multisensor with feed-forward ANNs. The sensors registered a detection range for both analytes of 0.2–20 μg/l with an overall assay time of less than 60 min. The individual inhibition pattern of each AChE–analyte combination enabled the discrimination of both analytes by the use of neural network data processing. Thus, paraoxon and carbofuran in mixtures displaying a concentration range of 0–20 μg/l for each analyte could be analysed with prediction errors of 0.9 μg/l for paraoxon and 1.4 μg/l for carbofuran.