Self-powered optical fiber integrated photoelectrochemical sensor based on MOFs for ascorbic acid detection

In biomedical testing, especially in clinical urine testing, the concentration of ascorbic acid (AA) can interfere with the accuracy of detecting other substance such as glucose, cholesterol and uric acid, which is a common issue that affects the reliability of clinical urine analysis. To eliminate the interference of AA in clinical urine detection, an optical fiber integrated photoelectrochemical (PEC) sensor based on metal organic framework (MOF) materials for urine ascorbic acid detection was developed in this paper. MOF materials, such as ZIF-8, not only improve the photoelectric conversion efficiency of PEC sensor, but also promote the enrichment of analytes owing to its large specific surface area and rich chemical groups. To our knowledge, this is the first application of MOF materials in optical fiber integrated PEC sensors. The optical fiber was modified with ITO/TiOx/ZIF-8/ZnS to fabricate an integrated probe. Finally, a self-powered integrated sensor was proposed based on the optical fiber and MOF materials. The results indicate that the sensor has a wide linear detection range from 10-6 M to 10–1.5 M for AA in artificial urine, a detection limit (LOD) of 0.45 μM, and strong specificity and repeatability. Meanwhile, the sensor has a response time as short as 0.3 s and a relative standard deviation (RSD) within 5 % in genuine urine. In conclusion, this sensor offers a new rapid detection method for AA in urine, with potential for practical detections, while expanding the development possibilities of optical fiber PEC sensors and the application scope of MOF materials.