An Amperometric Immunosensor for α-fetoprotein Based on Antibody Coated Nano ZrO_2-Au-poly Lysine Composite Membrane Modified Electrode

摘要

One novel amperometric immunosensor for a-fetop- rotein was fabricated which was modified by antibody immobilized on nano Zr02-Au-polyLysine composite membrane. Firstly, the deoxyribonucleic acid - phenoxyacetic acid isoniazid- Schiff base Co(II) complex (DNA-CoL) mixture film was casted on surface of multi carbon nanotubes(MWCNTs) modified glassy carbon electrode(GCE/CNTs/DNA-CoL). Then the composite nanoparticles (Zr02-Au-pLL) was employed to immobilize the antibody of a-fetoprotein(AFP) to produce the probes(Zr02-Au-pLL-anti AFP) for AFP. Finally the probes were modified on GCE/CNTs/DNA-CoL through the specific connection between DNA and Zr02 to form a novel nanocomposite membrane immunosensor for AFP(GCE/CNTs/ DNA-CoL/Zr02-Au-pLL-anti AFP). The function of immunosensor was investigated by scanning electron microscopy (SEM), cyclic voltammetry(CV), differential pulse voltammety (DPV) and electrochemical impedance spectroscopy experiment (EIS). The results indicated that combining the advantages of the MWNTs-DNA material and Zr02-Au-pLL-anti AFP nano probes, the immunosensor with excellent sensitivity and selectivity to AFP was prepared successfully.