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摘要
In this work, an ultrasensitive chemiluminescence (CL) aptasensor was prepared for indirect hemin detection based on hemin aptamer modified magnetic graphene oxide polymers (MGO@H-Atp@Co-PP). First, magnetic graphene oxide (MGO) was prepared, and MGO has a large specific surface area and easy separation characteristics. GO and MGO were characterized using scanning electron microscopy (SEM), X-ray powder diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Then, the hemin aptamer (H-Atp) was immobilized on the surface of the MGO, followed by cobalt porphyrin (Co-PP) being modified on its surface by the charge attracting effect between H-Atp and Co-PP. The immobilization properties of MGO to H-Atp and the adsorption properties of MGO@H-Atp to Co-PP were researched through the curves of kinetics and the curves of thermodynamics. When hemin existed in solution, Co-PP was removed from the surface of MGO@H-Atp@Co-PP due to the specific recognition ability between hemin and H-Atp while MGO@H-Atp@hemin was separated by a magnet, and Co-PP caused changes to the CL signal. So under optimized CL conditions, hemin could be assayed indirectly within the linear concentration range from 8.0 x 10(-11)-4.8 x 10(-8) mol L-1, and the detection limit was 3.9 x 10(-12) mol L-1 (3d) with the relative standard deviation (RSD) of 3.6%. The CL aptasensor was finally used for the determination of hemin in practical serum samples, and recoveries ranged from 97% to 105%. The satisfactory results revealed the potential applications of the MGO@H-Atp@Co-PP-CL aptasensor for hemin detection in monitoring of drugs and diagnosis of diseases.
