Dual-functional cubic cuprous oxide for non-enzymatic and oxygen-sensitive photoelectrochemical sensing of glucose

A novel non-enzymatic and oxygen-sensitive photoelectrochemical (PEC) sensor for glucose was first constructed based on dual-functional cubic cuprous oxide. Herein, cuprous oxide acts both as an excellent catalyst for the preoxidation of glucose and as a photocathode for the PEC non-enzymatic glucose sensing. The fabricated cuprous oxide was characterized by scanning electron microscopy, X-ray diffractometry, X-ray photoelectron spectrometry, and UV-vis spectrophotometry. Under the optimized conditions, the PEC sensing was linear in its response to the logarithm of concentration of glucose in the range of 0.0005 to 6 mmol L−1 with a detection limit of 0.3 μmol L−1. The same concentration of other common species did not interfere with the detection of glucose, and the results of the PEC sensor corresponded well with those obtained by the commercially available enzymatic glucose sensor. This novel non-enzymatic and oxygen-sensitive PEC sensor exhibited good performance with its high sensitivity, good selectivity, wide linear range, low cost, and portable features. Also it provides an alternative way for improving non-enzymatic PEC sensor of glucose.