Photoelectrochemical sensor based on the sensitive interface of photosensitive electrode for the detection of hydrogen peroxide in dried bean curds

A novel photoelectrochemical (PEC) sensor based on the sensitive interface of photosensitive electrode has been developed for the enzyme-free PEC response of hydrogen peroxide (H2O2). Polythionine (PTh) was polymerized on tin dioxide nanoparticles (SnO2 NPs) modified Indium Tin Oxide (ITO) electrode by scanning voltammetry. Characterization by scanning electron microscopy, Fourier transform infrared spectroscopy, and ultraviolet–visible spectroscopy showed that PTh was successfully polymerized on the surface of the photosensitive electrode and did not change the structure of SnO2 NPs. The PTh modified SnO2 NPs photosensitive electrode has excellent photoelectric performance, further enhancing the photocurrent response of H2O2. The calibration curve was linear in the range of 0.03–8 mM with a detection limit of 0.003 mM. The PEC sensor was successfully applied to detect H2O2 residues in dried bean curds. The results showed no remarkable difference compared with the reference iodometry method, suggesting that this alternative method can be used for the quality control analysis of dried bean curds.