2-(Perfluorooctyl) Ethyl Acrylate Functionalized Pervoskite: A Selective and Stable Photoelectrochemical Platform for Ultrasensitive Detection of Cholesterol

Herein, a novel ultrasensitive cholesterol photoelectrochemical (PEC) sensor was designed based on fluorinated molecularly imprinted polymers (FMIPs) functionalized CH3NH3PbI3@carbon nanodots (CH3NH3PbI3@CNDs) platform. 2-(Perfluorooctyl) ethyl acrylate (PFEA), a functional monomer, was chosen not only to endow CH3NH3PbI3 good selectivity but also improve its aqueous stability because of the fluorine containing long hydrophobic chain. Furthermore, the FMIPs can inhibit the recombination of electron holes and prolonged the carrier life time, and dramatically enhance the charge transfer efficiency by the reduction of defect density through the polymer passivation of grain boundaries of perovskite. The morphology, the enhanced hydrophobicity and photoelectric properties of FMIPs@CH3NH3PbI3@CNDs interface was characterized by transmission electron microscopy, Fourier transform infrared spectrum, scanning electron microscope, contact angle, photoluminescence spectrum and intensity modulated photovoltage spectrum, respectively. Under the optimized conditions, the linear range of the designed PEC sensor for cholesterol detection was 1.0 × 10−13–1.0 × 10−9 mol/L, and the detection limit was down to 8.9 × 10−14 mol/L. The new PEC sensor exhibited specific selectivity, good stability and hypersensitivity, and was successfully applied to cholesterol detection in human serum samples. This work extended the development of the MIPs based sensor and the high-performance perovskite.