Enhanced non-enzymatic glucose sensing of Cu–BTC-derived porous copper@carbon agglomerate

Porous copper@carbon agglomerate (PCCA) is prepared by pyrolysis of Cu₃(BTC)₂·3H₂O (Cu–BTC, BTC = 1,3,5-benzenetricarboxylic acid) in 5% H₂–N₂ mixture atmosphere. The phase and morphology evolution are thoroughly examined by XRD, Raman, BET, TG, XPS, SEM and TEM, respectively. The results show that PCCA is formed at 400 °C and maintains the cubic morphology of the original Cu–BTC crystal. PCCA is composed by round-shaped copper nanoparticles that covered outside by thin layer of carbon. The non-enzymatic glucose sensing properties of PCCA-modified glassy carbon electrode (Cu/GCE) are characterized by cyclic voltammetry. The sensor shows high sensitivity of 614.3 µA mM⁻¹ to glucose oxidation and negligible responses toward interference from uric acid, ascorbic acid, dopamine and l-cysteine at the level of their physiological concentrations. The sensor also exhibits rapid response (< 6 s), wide linear range (up to 3.33 mM) and low detection limit (0.29 µM at signal/noise ratio (S/N) = 3). Finally, the good stability, reproducibility and repeatability to glucose detection make PCCA a promising catalyst for non-enzymatic glucose sensor.