An enhanced photoelectrochemical sensor for aflatoxin B1 detection based on organic-inorganic heterojunction nanomaterial: poly(5-formylindole)/NiO

A new strategy for enhancing the photoelectric activity of poly(5-formylindole) (P5FIn) was developed by introducing the inorganic semiconductor material (NiO) to form organic-inorganic heterojunctions. P5FIn/NiO heterojunctions were firstly prepared by combining hydrothermal synthesis and electrochemical polymerization. Due to the synergistic effect between P5FIn and NiO, the photoelectrochemical (PEC) performance of this heterojunction was significantly enhanced compared to pure P5FIn and NiO. The reason for the enhanced PEC performance is mainly attributed to the increased visible light utilization and the bandgap matching effect of the P5FIn/NiO heterojunctions. Based on the prepared P5FIn/NiO heterojunctions, a novel PEC sensor for aflatoxin B1 (AFB1) detection was also constructed with a wide linear range of 0.005-50 ng mL(-1)and a limit of detection (LOD) of 0.0015 ng mL(-1). Moreover, this constructed PEC sensor also had good stability, reproducibility, selectivity, and satisfactory actual sample detection ability. This strategy may inspire more design and application of high-performance photoelectric active material based on inorganic semiconductor and organic conducting polymer heterojunctions.