An ultrasensitive and ultraselective chemiluminescence aptasensor for dopamine detection based on aptamers modified magnetic mesoporous silica @ graphite oxide polymers

[Display omitted] •Fe3O4·mSiO2·nSiO2@GO@D-Apt was successfully prepared.•The selectivity of the CL aptasensor was improved by the introduction of aptamers.•The CL aptasensor has high sensitivity with detection limit of 3.9×10−14mol/L.•The CL aptasensor has wide linear range of 2.5×10−13–2.0×10−9mol/L.•The CL aptasensor was successfully used for the determination in practical samples. In this work, an ultrasensitive and ultraselective chemiluminescence (CL) aptasensor was prepared for dopamine (DA) detection based on aptamers modified magnetic mesoporous silica @ graphite oxide polymers (Fe3O4·mSiO2·nSiO2@GO). Firstly, Fe3O4·mSiO2·nSiO2@GO and Au nanoparticles (AuNPs) were prepared and characterizated by transmission electron microscopy (TEM), scanning electron microscope (SEM), fourier transform infrared (FTIR), X-ray powder diffraction (XRD) and others. Then, dopamine aptamer (D-Apt) was immobilized on the surface of Fe3O4·mSiO2·nSiO2@GO while AuNPs was modified by ssDNA (a single stranded DNA partially complementary to D-Apt). The immobilization properties of Fe3O4·mSiO2·nSiO2@GO to D-Apt and the adsorption properties of Fe3O4·mSiO2·nSiO2@GO@D-Apt to AuNPs@ssDNA were researched sequentially. When DA existed, AuNPs@ssDNA was desorbed from the surface of Fe3O4·mSiO2·nSiO2@GO@D-Atp and catalyzed luminescence. After that, under optimized CL conditions, DA could be measured with the linear concentration range of 2.5×10−13 to 2.0×10−9mol/L. The detection limit was 3.9×10−14mol/L (3δ) while the relative standard deviation (RSD) was 2.6%. Finally, the Fe3O4·mSiO2·nSiO2@GO@D-Apt/AuNPs@ssDNA − CL aptasensor was used for the determination of DA in practical samples and recoveries ranged from 98.0% to 102.0%. Those satisfactory results clarified the proposed CL aptasensor achieved ultraselective, ultrasensitive and reliable detection of DA and revealed potential application in monitoring and diagnosis of human neurological diseases.