Carbon dots-anchored and stabilized nano Cu/Cu2O composites for constructing highly sensitive and stable non-enzymatic glucose electrochemical sensor

A flexible non-enzymatic glucose electrochemical sensor with high sensitivity and stability was constructed using the electrode by in situ growth of Cu/Cu 2 O nanocomposites on carbon dots (CDs) modified carbon cloth (CC) by electrodeposition reduction method, where the modification of CDs provided a stable anchoring site for the growth of the nanocomposites and enhanced the stability of Cu/Cu 2 O in solution. The electrode had a glucose detection range of 0.2-100 μM and 0.1-1 mM, which offered the advantages of high sensitivity (4510.89 μA mM -1 cm -2 and 2385.94 μA mM -1 cm -2 ) and low detection limit (0.66 μM). The sensor also exhibits excellent selectivity, reproducibility, immunity to interference and long-term stability. In addition, In order to verify the enhancement effect of CDs on their electrochemical properties, Cu/Cu 2 O electrodes were prepared in this paper by the same method on several CCs modified with different CDs (e.g., glycine, cysteine and riboflavin), The results showed that the incorporation of CDs enhanced the electrocatalytic ability compared to the electrode without CDs modification, indicating that CDs can provide more active sites and electron transport channels for Cu/Cu 2 O, and that this CDs-enhanced Cu/Cu 2 O nanocomposite can be used for non-enzymatic glucose electrochemical sensors. (a)The process of carbon-dots-modified carbon cloth. (b) Schematic diagram of the preparation process and reaction mechanism with glucose for Cu/Cu 2 O nanomaterials. • Hyperhydrophilic carbon cloth (CC) prepared by in situ growth of carbon dots (CDs) can provide additional anchoring sites for Cu/Cu 2 O and enhance electrocatalytic activity. • CDs from various carbon sources enhance CC hydrophilicity and active area. • Flexible, non-enzymatic glucose sensor with wide detection range and high sensitivity. • Sensor shows excellent selectivity, reproducibility, and long-term stability. • Different CDs-modified CC provide more electron transport channels for Cu/Cu 2 O and enhance electrochemical stability.