Molecularly imprinted polymers and PEG double engineered perovskite: an efficient platform for constructing aqueous solution feasible photoelectrochemical sensor

Abstract

Herein, a kind of dual polymers, molecularly imprinted polymers (MIPs) and polyethylene glycol (PEG), coated perovskite (MIP-PEG/CH3NH3PbI3) was synthesized and used to construct a photoelectrochemical (PEC) sensor for salicylic acid (SA) detection. A selective MIP layer for SA recognition was anchored on the PEG modified CH3NH3PbI3 through a facile UV-polymerization process. PEG benefits the water-resistant ability of CH3NH3PbI3 and MIPs endows the photoactive CH3NH3PbI3 good selectivity. Thanks to the protection from PEG and MIPs, the MIP-PEG/CH3NH3PbI3 product showed stable photocurrents in aqueous solution. Furthermore, methylammonium iodide (MAI) contained electrolyte was used in which MAI could restore the degraded part of CH3NH3PbI3 to improve its stability. SA was detected by monitoring the photocurrent signal changes of the PEC sensor resulting from the reaction between SA and MIPs. The as-fabricated PEC sensor showed good performance in terms of sensitivity and selectivity. The linear range between the photocurrent changes and the concentrations of SA was from 1.0 × 10-15 to 7.0 × 10-11 M. This work unveiled the promise of organic-inorganic hybrid lead halide perovskite based structure for PEC sensors and inspired more interests in the development of diverse perovskite-based materials for advanced PEC analysis.