Cu₂O Microspheres Supported on Sulfur-Doped Carbon Nanotubes for Glucose Sensing

Metal oxide-based nano/microstructures assembled on heteroatom-doped carbon nanomaterials are promising materials to design the electrocatalysts with enhanced electrochemical performances. In this work, a systematic protocol was contrived to fabricate hybrid electrode material based on Cu2O microspheres (MSs) supported on sulfur-doped multiwalled carbon nanotubes (Cu2O MSs/S-MWCNTs). The adequate doping of sulfur and successful fabrication of Cu2O MSs/S-MWCNTs were confirmed by various microscopic and spectroscopic techniques, and then the tailor-made Cu2O MSs/S-MWCNTs composite was employed to establish a nonenzymatic sensing system for controlled monitoring of glucose. A high surface area of Cu2O MSs and sulfur doping inside the MWCNTs collectively enhanced the electrocatalytic activity of Cu2O MSs/S-MWCNTs as revealed through cyclic voltammetry (CV) analysis. The enhanced electrochemical efficacy of Cu2O MSs/S-MWCNTs may be credited to the creation of heterojunctions during the doping process, forming the highly defected structures with increased number of catalytic active sites. In addition, the Cu2O MSs/S-MWCNTs/GCE presented the good amperometric response for glucose sensing attaining optimal linear range, satisfactory sensitivity, excellent stability, and glucose specific selectivity. These unique chemical and electrochemical features strongly encourage the potential applicability of our designed Cu2O MSs/S-MWCNT electrocatalyst for targeted monitoring of glucose.