Cu Aerogels with Sustainable Cu(I)/Cu(II) Redox Cycles for Sensitive Nonenzymatic Glucose Sensing

Developing functional nanomaterials for nonenzymatic glucose electrochemical sensing platforms is vital and challenging from the perspective of pathology and physiology. Accurate identification of active sites and thorough investigation of catalytic mechanisms are critical prerequisites for the design of advanced catalysts for electrochemical sensing. Herein, Cu aerogels are synthesized as a model system for sensitive nonenzymatic glucose sensing. The resultant Cu aerogels exhibit good catalytic activity for glucose electrooxidation with high sensitivity and a low detection limit. Significantly, in situ electrochemical investigations and Raman characterizations reveal the catalytic mechanism of Cu-based nonenzymatic glucose sensing. During the electrocatalytic oxidation of glucose, Cu(I) is electrochemically oxidized to generate Cu(II), and the resultant Cu(II) is spontaneously reduced back to Cu(I) by glucose, achieving the sustained Cu(I)/Cu(II) redox cycles. This study provides profound insights into the catalytic mechanism for nonenzymatic glucose sensing, which provides great potential guidance for a rational design of advanced catalysts in the future.