A highly sensitive multi-catalytic sensing system for organophosphorus and organochlorine pesticides based on the peroxidase-like activity of ferric ions

Developing rapid, efficient and highly sensitive sensing systems for organophosphorus (OPs) and organochlorine pesticides is important due to their potential damage to human health. Considering that Fe3+ ions were recently found to have much higher peroxidase-like activity than that of Fe3O4 magnetic nanoparticles, in this work, a novel and highly sensitive multi-catalytic sensing system has been successfully developed for OPs and organochlorine pesticides, on the basis of the color reaction of 3,3′,5,5′-tetramethyl benzidine (TMB) driven by Fe3+ ions, together with two enzymatic catalytic systems of acetylcholinesterase (AChE) and choline oxidase (CHO). Sub nM level limits of detection could be achieved for four tested OPs and organochlorine pesticides. Furthermore, several fruit/vegetable samples were successfully employed for evaluating this established sensing system.