A novel reduction approach to fabricate quantum-sized SnO2-conjugated reduced graphene oxide nanocomposites as non-enzymatic glucose sensors

Abstract

Quantum-sized SnO₂ nanocrystals can be well dispersed on reduced graphene oxide (rGO) nanosheets through a convenient one-pot in situ reduction route without using any other chemical reagent or source. Highly reactive metastable tin oxide (SnO_x) nanoparticles (NPs) were used as reducing agents and composite precursors derived by the laser ablation in liquid (LAL) technique. Moreover, the growth and phase transition of LAL-induced SnO_x NPs and graphene oxide (GO) were examined by optical absorption, X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy and high-resolution transmission electron microscopy. Highly dispersed SnO_x NPs can also prevent rGO from being restacked into a multilayer structure during GO reduction. Given the good electron transfer ability and unsaturated dangling bonds of rGO, as well as the ample electrocatalytic active sites of quantum-sized SnO₂ NPs on unfolded rGO sheets, the fabricated SnO₂–rGO nanocomposite exhibited excellent performance in the non-enzymatic electrochemical detection of glucose molecules. The use of LAL-induced reactive NPs for in situ GO reduction is also expected to be a universal and environmentally friendly approach for the formation of various rGO-based nanocomposites.