3D graphene/copper oxide nano-flowers based acetylcholinesterase biosensor for sensitive detection of organophosphate pesticides

In the present study, we developed a highly sensitivity electrochemical acetylcholinesterase (AChE, E.C.3.1.1.7) biosensor for organophosphorous pesticides (OPs) detection on the basis of three dimensional graphene-copper oxide nanoflowers nanocomposites (3DG-CuO NFs). The 3DG-CuO NFs nanocomposites with network-like structure not only increase the effective specific surface area, but also provide a favorable microenvironment for AChE loading, which could improve the biosensor performance. The electrochemical performance of the AChE-CS/3DG-CuO NFs/GCE biosensor was thoroughly investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), amperometry (i-t) and square wave voltammetry (SWV). Under the optimal detection conditions, the AChE-CS/3DG-CuO NFs/GCE biosensor exhibits advantages such as a wide linear relationship to malathion ranging from 1 ppt to 15.555 ppb (3 pM-46.665 nM). The theoretical detection limit was calculated to be 0.31 ppt (0.92 pM) with good selectivity and ideal stability. Most importantly, satisfactory recoveries were achieved in real samples analysis, indicating that our developed biosensor has great potential to be an effective platform for pesticides detection.