A photoelectrochemical sensor for glutathione based on Bi2S3-modified TiO2 nanotube arrays

Abstract

A novel photoelectrochemical sensor was designed for the determination of glutathione based on Bi₂S₃-modified TiO₂ nanotube arrays. Combined with anodization and a successive ionic layer adsorption reaction, a highly ordered and controllable nano array heterojunction was systematically constructed. The results of characterization prove that it can enhance the light absorption efficiency and accelerate the charge transfer. Under visible light excitation and a bias voltage of 0.65 V, the proposed PEC sensor exhibited a sensitive response for glutathione with a linear range from 15.0 μmol L⁻¹ to 200 μmol L⁻¹ and a detection limit of 7.00 μmol L⁻¹ (S/N = 3). It also demonstrated good stability and reproducibility. In addition, this approach was successfully applied for the determination of glutathione in actual reduced glutathione tablets with satisfactory results.