1D/2D SnO2/SnS2 heterojunctions coupling with PtPd/CeO2 heterostructured nanozyme for ultrasensitive PEC apatasensing of lincomycin

Lincomycin (LIN), as one of antibiotics, is often present in feed and animal products, whose abuse would cause serious side effects for human health or even death. Thus, its screening and quantitative assay is crucial in diverse matrix. Herein, SnO2 nanorods were efficiently anchored on SnS2 nanosheets to form the 1D/2D SnO2/SnS2 heterojunctions, coupled by illuminating the enhanced PEC mechanism. In parallel, tiny PtPd nanoparticles (NPs) were in situ grown on CeO2 nanorods (termed PtPd/CeO2), whose peroxidase-like property was carefully investigated by 3,3′,5,5′-tetramethylbenzidin oxidation in the presence of H2O2. Based on the above foundation, a novel photoelectrochemical (PEC) aptasensor was built for assay of LIN, coupled with the home-made PtPd/CeO2 heterostructured nanozyme for signal amplification via catalytic oxidation of 3,3′-diaminobenzidine to generate insoluble precipitates on the SnO2/SnS2 photoanode. The resultant biosensor had a wider linear range of 0.001 ∼ 100 nM and a lower limit of detection (LOD) of 0.75 pM (S/N = 3). This study provides some constructive insights for bioanalysis of antibiotics in actual environment and food samples.