Synergistic Engineering of Tri-Metallic CoCuMoOx Oxides on Electrochemically Derived MoOx for High-Performance Non-Enzymatic Glucose Sensing

Tri-metallic CoCuMoO x oxides were prepared as efficient glucose sensor. • The high-valence Mo 6+ can act as an electron acceptor for glucose oxidation. • A new pathway for Co 2+ and Cu 2+ to oxidize glucose was activated by Mo 6+ . The accurate and efficient non-enzymatic detection of glucose remains a significant challenge. This study reports a novel tri-metallic CoCuMoO x oxide synthesized via the co-deposition of Co 2+ and Cu 2+ on electrochemical oxidation derived MoO x as sensitive glucose sensor. The incorporated Co 2+ and Cu 2+ bring real active sites Co 2+/3+ , Co 3+/4+ , and Cu 2+/3+ redox couples for electrochemical oxidation of glucose. More importantly, the inactive Mo 6+ can activate the Co 2+ and Cu 2+ sites for glucose oxidation by acting as an electron acceptor. Due to the new pathway activated by Mo 6+ , the optimized CoCuMoO x @CC electrode exhibits superior glucose sensing performance, including a high sensitivity of 5958.7 μA·mmol −1 ·cm −2 in the linear range of 10 μmol to 1 mmol, a rapid response time of 3 s, a low detection limit of 2.2 μmol, and superior anti-interference performance. Meanwhile, the electrochemical measurements show good long-term stability of CoCuMoO x @CC electrode, with 92.5% of the original current remained at the 28th day. This work not only develops a promising non-enzymatic glucose sensing material but also advances the material design principles for glucose sensors based on high-valence transition metal ions. The incorporated Co 2+ and Cu 2+ bring real active sites Co 2+/3+ , Co 3+/4+ , and Cu 2+/3+ for electrochemical oxidation of glucose. More importantly, the inactive Mo 6+ can activate the Co 2+ and Cu 2+ sites for glucose oxidation by acting as an electron acceptor. Download: Download high-res image (141KB) Download: Download full-size image