Amperometric detection of organophosphate and carbamate pesticides Based on AuNPs/graphene-PEDOT:PSS nanocomposites modified electrode

The disposable electrochemical biosensor based on enzyme inhibition were constructed for detection of organophosphate and carbamate pesticides. The nanocomposite film of gold nanoparticles and graphene/PEDOT-PSS were prepared on the surface of screen-printed carbon based electrodes (SPCEs). Acetylcholinesterase enzyme was immobilized onto the film via cross-linking method. The composite film provides specific surface area and high conductivity. A significant synergistic effect of nanocomposites on the biosensor performance was observed in sensing of acetylthiocholine chloride and the inhibition of paraoxon and carbofuran. Graphene/PEDOT-PSS/AuNPs enhanced electron transfer reaction at a lower potential and catalyzed the electrooxidation of thiocholine. Based on the inhibition of paraoxon on the AChE activity, a Unear range of 10-400 ppb were obtained. For carbofuran determination, two Unear ranges at 0.5-10 and 200-500 ppb can be found. The developed biosensor exhibited good sensitivity and providing a good promising tool for pesticides analysis.