Integration of high-entropy nanozyme and hollow In2S3 nanotube heterostructures decorated with WO3 for ultrasensitive PEC aptasensing of highly toxic mycotoxin

As a highly toxic mycotoxin, patulin threatens human and animal health. Herein, a new signal amplification strategy was designed for photoelectrochemical (PEC) analysis of patulin based on nanotube-like In2S3/WO3 heterostructures with the assistance of PtRuFeCoW high-entropy alloy nanorods (HEANRs). Specifically, the prominent photoactivity of the In2S3/WO3 was investigated by UV−vis diffuse reflectance and photoluminescence spectroscopy, coupled by elaborating the photoelectron transport mechanism in detail. Simultaneously, the excellent peroxidase-like activity of the PtRuFeCoW HEANRs was certificated mainly by UV-vis absorption spectroscopy. On such foundation, the PtRuFeCoW HEANRs modified capture DNA was cast onto the In2S3/WO3 based photoanode for catalyzing 4-chloro-1-naphthol (4-CN) oxidation to form insoluble benz-4-chloro-hexadienone (4-CD) precipitate in the presence of H2O2, ultimately weakening the PEC currents. The resulting PEC sensor exhibited a wider detection range from 0.1 pg mL−1 to 500 ng mL−1 and a lower detection limit was down to 0.063 pg mL−1 (S/N = 3). The HEANRs nanozyme assisted PEC method holds great promise for ultrasensitive detection of environmental pollutants in practice.