Non-enzymatic glucose biosensor based on palladium-copper oxide nanocomposites synthesized via galvanic replacement reaction

Abstract

A non-enzymatic glucose sensor was fabricated facilely by immobilization of bimetallic Cu2O@Pd nanocomposites onto the surface of a pretreated bare glassy electrode via the galvanic replacement reaction. The morphology and composition of the hollow-cubic Cu2O@Pd nanocomposites were investigated by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray diffraction (XRD) and inductively coupled plasma optical emission spectrometry (ICP-OES). The electrocatalytic properties of the modified electrode towards glucose oxidation were evaluated by cyclic voltammetry (CV) and chronoamperometry. The hollow-cubic Cu2O@Pd nanocomposites modified glassy carbon electrode showed high electrocatalytic activity towards the oxidation of glucose in alkaline media due to the facile mass transport of the hollow-cubic structure and the synergistic and bifunctional effects between Pd and Cu2O. Under experimentally optimal conditions, the designed sensor showed a linear range from 0.49μM to 8.0mM with a current sensitivity of 19.44μAmM−1 and a low detection limit of 0.16μM. Furthermore, high selectivity, favorable reproducibility, and long-term performance stability were observed. In addition, test results demonstrated that optimized electrodes can be applied to determining the glucose in real blood serum samples. All these observations manifest that the hollow-cubic Cu2O@Pd nanocomposites modified electrodes are potential candidates for routine glucose analysis.