A Donor-Acceptor-Type Photoactive Material Based Cathode Molecularly Imprinted Photoelectrochemical Sensor for Luteolin

Developing new optoelectronic materials is the eternal pursuit and key strategy for building high-performance photoelectrochemical sensors. In this work, a novel organic polymer film containing D-A unit was firstly in-situ electro-synthesized on ZnS/rGO surface by using 9,9’-(9,9’-spirobi[fluorene]-2,7-diyl)-bis-9H-carbazole (SFC) and carbazole as functional monomers. The micromorphology, element composition, structure, photoelectric efficiency and recognition ability of the key component and/or the sensing composite were investigated by SEM, XPS, XRD and transient photocurrent spectra, and the possible mechanism of charge carrier separation and transmission was proposed. Owing to the good light absorption ability, excellent film formation and imprinting ability, effective electrons-holes separation path, and satisfactory application stability, the prepared photoelectrochemical sensor exhibited good sensing performance for luteolin. Under the optimized conditions, the photocurrent intensity of the sensor showed a good linear relationship with the logarithmic concentration of luteolin from 0.001 μmol L−1 to 2 μmol L−1, with a detection limit of 0.35 nmol L−1 (S/N=3). When applied in actual samples including carrot, peanut shells and chrysanthemum tea, highly consistent results with classical HPLC method were obtained. This work provided a new photoelectrochemical approach for the highly selective and sensitive detection of small molecules besides luteolin.