Cu@Ni core–shell nanoparticles/reduced graphene oxide nanocomposites for nonenzymatic glucose sensor

Abstract

In this work, the Cu_x@Ni_100−x core–shell nanoparticles (CSNPs) are deposited on reduced graphene oxide (rGO) sheets, and this nanocomposites (in a Nafion matrix) are shown to be a viable materials for nonenzymatic sensing of glucose. A novel nonenzymatic glucose sensor based on a glass carbon electrode modified with Cu₅₃@Ni₄₇ CSNPs/rGO (referred to as Cu₅₃@Ni₄₇ CSNPs/rGO/GCE) displays an enhanced electrocatalytic activity to glucose oxidation in 0.1 M NaOH solution than that of Cu/GCE, Ni/GCE, Cu/rGO/GCE, Ni/rGO/GCE, and Cu₅₂@Ni₄₈ CSNPs/GCE, respectively. This is attributed to the three-in-one synergetic effects from their bimetallic compositions, specific core–shell structures, and interactions from the bimetallic CSNPs and support materials of rGO sheets. At an applied potential of +0.575 V (vs. SCE), the electrode has a low detection limit (0.5 μM; S/N = 3), a very wide linear range (0.001 mM to 4.1 mM), high sensitivity (780 μA mM⁻¹ cm⁻²), and a fast response time (3 s). Thus, it has great potential for the development of nonenzymatic glucose sensors.