A novel “signal-off” photoelectrochemical sensing platform for selective detection of rutin based on Cu2SnS3/TiO2 heterojunction

Abstract

In this study, a novel and ultrasensitive photoelectrochemical (PEC) sensor was developed for highly selective detection of rutin with a “signal-off” pattern based on Cu2SnS3-modified TiO2 nanotube arrays (NTAs) under UV light irradiation. Herein, the highly ordered TiO2 nanotube arrays were grown on the surface of Ti foil using an anodization process, and then Cu2SnS3 nanoparticles (NPs) were deposited on TiO2 NTAs by electrodeposition method. It was found that the Cu2SnS3/TiO2 NTAs/Ti electrode exhibited a much-increased photocurrent response compared to the bare TiO2 NTAs/Ti electrode owing to the synergistic effect between Cu2SnS3 nanoparticles and TiO2 NTAs, which could accelerate the separation of electron-hole pairs. In the presence of rutin,the PEC response was reduced due to the steric hindrance effect caused by the interaction between Cu2SnS3 nanoparticles and rutin. Under optimum conditions, the fabricated PEC sensor indicated a widespread linear range of 0.001 nM–100 µM toward rutin with an extremely low detection limit (LOD) of 0.0007 nM. Moreover, the experimental results revealed that the proposed PEC sensor possessed good stability, favorable selectivity, outstanding repeatability, and reproducibility. Meanwhile, the proposed PEC sensor was successfully used to determine rutin content in real samples, and satisfactoryresults were obtained.