High sensitive visible light photoelectrochemical sensor based on in-situ prepared flexible Sn3O4 nanosheets and molecularly imprinted polymers

This work described the construction of a novel photoelectrochemical platform with Sn3O4 which was in-situ decorated on a carbon fiber paper (Sn3O4@CFP) as the visible light-active species, and molecularly imprinted polymers (MIPs) as the recognition element. This is the first attempt to apply Sn3O4 in the field of photoelectrochemical sensors. Sn3O4 nanoplates were directly grown on CFPs by a simple hydrothermal process. The MIP layer with special selectivity for 2,4-dichlorophenoxyacetic acid (2,4-D), a kind of carcinogen, was prepared on the Sn3O4@CFP by electropolymerizing pyrrole in the presence of 2,4-D. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) techniques were used to characterize the as-prepared Sn3O4@CFP. Benefiting from the structural advantages of Sn3O4@CFP and selectivity of MIP, the binder-free PEC sensor affords a linearity from 5.0 × 10−11 to 1.0 × 10−7 M for 2,4-D and the detection limit was down to 1.08 × 10−11 M. This PEC platform demonstrates excellent stability, reproducibility, remarkably convenience, and cost-effective advantages, as well as low detection limit. The successful detection of 2,4-D in bean sprout samples has been acquired. Furthermore, the flexibility of the Sn3O4@CFP offers an easy integration of PEC sensor onto different non-planar shape and size surfaces which extends its applications for sensors construction.