Donor-acceptor photoelectrochemical strategy for efficient detection and degradation chloramphenicol based on dual-porphyrin Z-scheme heterostructure

Abstract

Nowadays, developing a new strategy to construct highly efficient photoelectric active materials is imperative but challenging for photoelectrochemical (PEC) technology applications in the fields of pollutant analysis and degradation. Inspired by natural photosynthesis, a novel Z-scheme heterojunctions-based cathodic “signal-on” PEC aptasensor was constructed based on the electron donor-acceptor (D-A) strategy. The Z-scheme heterojunctions were fabricated by self-assembly of porphyrin and copper-porphyrin metal-organic framework (Cu-PorMOF), which possessed excellent electron-donor properties. The D-A strategy is based on the interaction between the photocathode and electron acceptor analyte, which has the advantages of simple construction of the sensing interface and strong anti-interference capability, highlighting the broad applicability of PEC sensing technology in the analysis of complex samples. Chloramphenicol (CAP) was selected as a representative of electron-acceptor analyte for the validation of the PEC sensing ability. The experimental results showed that the constructed PEC sensor exhibited a high sensitivity with a wide linear range from 2 to 200 nM and a low detection limit of 0.5 nM (3 S/N). Furthermore, the heterojunctions could efficiently degrade CAP, and the degradation processes were in situ online monitored using scanning photoelectrochemical microscopy technology. Overall, this work provides an integrated strategy to detect and degrade CAP by engineering the interfacial structure of heterojunctions.