A photoelectrochemical sensor for glutathione detection without additional electron donor using CNTs/Bi4VO8Br/CdS nanocomposites

The concentration of glutathione in the human body has a significant impact on health, which highlights the increasing urgency to develop highly sensitive methods for its detection. In this study, indium tin oxide (ITO) conductive glass was used as the substrate, and CNTs/Bi4VO8Br nanocomposites and CdS were sequentially modified, which were used as sensing and recognition elements. The usage of CNTs in the electrode design provides enhanced electron transfer rates due to their excellent conductivity, which ultimately results in an increase in the photocurrent intensity. Furthermore, the sensitization effect of CdS in the nanocomposite significantly improves the photocurrent intensity of the sensing system. Utilizing the exceptional photoelectrochemical properties of the aforementioned materials, a highly sensitive photoelectrochemical sensor has been developed for the detection of glutathione. The sensor effectively detects glutathione in the concentration range of 5–1000 μmol/L, with a detection limit of 0.67 μmol/L (S/N = 3). Additionally, the constructed sensor exhibits excellent stability, specificity, and reproducibility.