Novel competitive photoelectrochemical sensor array based on ZnIn2S4/CdS heterojunction for highly sensitive detection of dibutyl phthalate in the environment

Abstract

Dibutyl phthalate (DBP) is a common plasticizer used in the manufacture and processing of plastic products. Given that DBP is easily leached and released into the environment, posing a threat to nature and organisms, a competitive photoelectrochemical (PEC) sensor array based on Z-type heterojunction with self-calibration was designed for DBP detection. In this experiment, ZnIn₂S₄ nanosheets were uniformly formed on indium tin oxide transparent conducting glass (ITO) using a hydrothermal method and then CdS nanorods were in situ grown onto the ZnIn₂S₄ through the same method. The Z-type heterojunctions formed by the ZnIn₂S₄/CdS composites exhibit a wide range of light absorption and high efficiency of photogenerated electron and hole separation, offering significant advantages for PEC sensor. Thereafter, with the DBP antibody as the target and the competition strategy between the DBP and corresponding antigen to realize the detection of the DBP. Furthermore, the implementation of a self-calibration strategy enhances the precision of experimental outcomes. In accordance with the optimal experimental conditions, the competitive PEC sensor array with self-calibration demonstrated satisfactory linearity across the DBP concentration spectrum of 0.001–100 ng mL⁻¹, with a detection limit of 0.21 pg mL⁻¹ (S/N = 3) for DBP. The experimental results demonstrated that the PEC sensor array exhibited excellent stability, specificity, and reproducibility. The study offers novel insights into the detection of DBP in the environment.