Highly selective and sensitive chemiluminescence biosensor for adenosine detection based on carbon quantum dots catalyzing luminescence released from aptamers functionalized graphene@magnetic beta-cyclodextrin polymers

摘要

In this work, a highly selective and sensitive chemiluminescence (CL) biosensor was prepared for adenosine (AD) detection based on carbon quantum dots (CQDs) catalyzing the CL system of luminol-H2O2 under alkaline environment and CQDs was released from the surface of AD aptamers functionalized graphene @ magnetic beta-cyclodextrin polymers (GO@Fe3O4@beta-CD@A-Apt). Firstly, GO@Fe3O4@beta-CD and CQDs were prepared and characterized by transmission electron microscopy (TEM), scanning electron microscope (SEM), UV-Vis absorption spectra (UV), fluorescence spectra (FL), fourier transform infrared (FTIR) and X-ray powder diffraction (XRD). For GO@Fe3O4@beta-CD, Fe3O4 was easy to separate, GO had good biocompatibility and large specific surface area, and beta-CD further increased the specific surface area of the adenosine polymers (A-Apt) to provided larger binding sites to A-Apt. Then, A-Apt was modified on the surface of GO@Fe3O4@beta-CD while CQDs was modified by ssDNA (a single stranded DNA partially complementary to A-Apt). The immobilization property (GO@Fe3O4@beta-CD to A-Apt) and the adsorption property (GO@Fe3O4@beta-CD@A-Apt to CQDs-ssDNA) were sequentially researched. The base-supported chain-like polymers - GO@Fe3O4@beta-CD@A-Apt/CQDs-ssDNA was successfully obtained. When AD existed, CQDs-ssDNA was released from the surface of GO@Fe3O4@beta-CD@A-Apt and catalyzed CL. After that, under optimized CL conditions, AD could be measured with the linear concentration range of 5.0 x 10(-13)-5.0 x 10(-9) mol/L and the detection limit of 2.1 x 10(-13) mol/L (38) while the relative standard deviation (RSD) was 1.4%. Finally, the GO@Fe3O4@beta-CD@A-Apt/CQDs-ssDNA-CL biosensor was used for the determination of AD in urine samples and recoveries ranged from 98.6% to 101.0%. Those satisfactory results illustrated the proposed CL biosensor could achieve highly selective, sensitive and reliable detection of AD and revealed potential application for AD detection in monitoring an