Metronidazole determination with an extremely sensitive and selective electrochemical sensor based on graphene nanoplatelets and molecularly imprinted polymers on graphene quantum dots

An extremely sensitive and selective electrochemical sensor based on a modified glassy carbon electrode (GCE) for metronidazole (MNZ) determination was developed. At first, molecularly imprinted polymers (MIPs) on the surface of graphene quantum dots (GQDs) was synthesized via sol-gel method. Then, it was dropped on the surface of GCE that modified with graphene nanoplatelets (GNPs). The excellent synergistic effect of GNPs and MIPs shows significantly enhanced electrocatalytic activity for MNZ. Electrochemical behavior of the imprinted electrochemical sensor was studied by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). Several effective parameters on the sensor response were investigated and optimized. The proposed imprinted electrochemical sensor, under the optimized conditions, showed two linear dynamic ranges from 0.005 to 0.75 mu mol L-1 and 0.75-10.0 mu mol L-1 with a low detection limit of 0.52 nmol L-1 for MNZ determination. Finally, the proposed sensor was used for MNZ analysis in human blood plasma samples and provided acceptable results. (C) 2018 Elsevier B.V. All rights reserved.