Nickel nanoparticles modified conducting polymer composite of reduced graphene oxide doped poly(3,4-ethylenedioxythiophene) for enhanced nonenzymatic glucose sensing

A facile two-step electrochemical strategy was reported to synthesize nanocomposite of reduced graphene oxide (RGO) doped conducting polymer poly (3,4-ethylenedioxythiophene) (PEDOT) decorated with nickel nanoparticles (NiNPs) onto a glassy carbon electrode (GCE). Pure graphene oxide (GO) doped PEDOT composite was firstly electropolymerized onto the GCE through cyclic voltammetry, followed by electrochemical reduction in a solution containing nickel cations at a constant potential of −0.9 V. During the electrochemical reduction process, GO doped in the PEDOT composite would be reduced to a more conductive form of RGO, and at the same time, nickel cations could be reduced to form NiNPs and loaded on the composite surface. The prepared nanocomposite (NiNPs/PEDOT/RGO) modified electrode showed outstanding electrocatalytic activity toward the oxidation of glucose in alkaline media, and it could be developed into a nonenzymatic glucose sensor. Under optimum conditions, the glucose sensor exhibited a linear range from 1.0 μM to 5.1 mM and a detection limit of 0.8 μM (S/N = 3), associated with excellent stability, high reproducibility and favorable selectivity against common interferents. Furthermore, the nonenzymatic sensor was also successfully applied to the detection of glucose in human serum samples, showing promising potential in the clinical application.