Synthesis of carbon quantum dot-decorated V₂O₅ nanobelts for non-enzymatic glucose sensing

Carbon quantum dots (CQDs) were prepared via a hydrothermal method using glucose and citric acid as precursors. The synthesized CQDs and V2O5 nanomaterials were characterized using TEM, SEM and XPS, while their optical properties were analyzed by UV-Vis and fluorescence spectroscopy. The fluorescence of CQDs in aqueous solution was significantly quenched in the presence of V2O5 nanomaterials. At pH 8.2, the addition of glucose to the CQDs + V2O5 nanocomposite solution induced the reduction of V5+ to V4+ in V2O5, resulting in the fluorescence recovery of CQDs. Glucose could be quantitatively detected using CQDs + V2O5 nanocomposite, exhibiting a wide linear range (0.1 - 1000 μmol/L) and a low detection limit (0.539 μmol/L). Furthermore, the selectivity and anti-interference capability of the CQDs + V2O5 nanocomposite for glucose detection were investigated. Additionally, cytotoxicity assays and cellular imaging of CQDs were conducted. Overall, the integration of CQDs + V2O5 nanocomposite demonstrates potential as a novel diagnostic platform for non-enzymatic glucose detection in clinical applications