In-site synthesis of an inorganic-framework molecular imprinted TiO2/CdS heterostructure for the photoelectrochemical sensing of bisphenol A

Abstract

In this study, we develop a highly sensitive and selective photoelectrochemical (PEC) sensor for bisphenol A (BPA) determination by combining a TiO₂/CdS heterostructure with inorganic framework molecular imprinting (MI) technology. A MI-TiO₂/CdS heterostructure was synthesized via successive ionic layer adsorption combined with an inorganic framework molecular imprinting method. Due to the matched energy level distribution of TiO₂ with CdS, the formed heterojunction promotes photogenerated charge separation and enhanced PEC conversion. The MI-TiO₂/CdS based PEC sensor exhibits higher photocurrent responses and perfect selectivity for BPA under simulated sunlight irradiation. Benefiting from the unique heterostructure and special recognition ability of MI-TiO₂/CdS, the photocurrent is linear to the concentration of BPA (range from 1 to 100 pmol L⁻¹), with a low limit detection of 0.5 pmol L⁻¹ (S/N = 3). Meanwhile, the detection results show that the PEC sensor exhibits excellent sensitivity, high selectivity, and good stability. Furthermore, the PEC sensor was successfully applied to the real environmental sample detection of BPA, in lake and river water, domestic wastewater and tap water. This PEC sensor exhibits favourable BPA detection, and it is also a promising method by which to measure other similar environmental substances selectively and sensitively in future work.