An Enzyme-Free Photoelectrochemical Sensor Platform for Ascorbic Acid Detection in Human Urine

A novel enzyme-free photoelectrochemical (PEC) potential measurement system based on Dy-OSCN was designed for ascorbic acid (AA) detection. The separation and transmission of internal carriers were accelerated and the chemical properties became more stable under light excitation due to the regular microstructure of the prepared Dy-OSCN monocrystal. More importantly, the PEC potential method (OCPT, open circuit potential-time) used in this work was conducive to the reduction of photoelectric corrosion and less interference introduced during the detection process, which effectively ensured the repeatability and stability of the electrode. Under optimal conditions, the monocrystal successfully served as a matrix for the detection of AA, and the prepared PEC sensor exhibited a wide linear range from 7.94 × 10−6 mol/L to 1.113 × 10−2 mol/L and a sensitive detection limit of 3.35 μM. Practical human urine sample analysis further revealed the accuracy and feasibility of the Dy-OSCN-based PEC platform. It is expected that such a PEC sensor would provide a new way for rapid and non-invasive AA level assessment in human body constitution monitoring and lays a foundation for the further development of practical products.