A Non-enzyme Amperometric Immunosensor for Rapid Determination of Human Immunodeficiency Virus p24 Based on Magnetism Controlled Carbon Nanotubes Modified Printed Electrode

A magnetism controlled and non-enzyme amperometric immunosensor was fabricated for the determination of human immunodeficiency virus p24 (HIV p24). First, Fe3O4/Au composite nanoparticles (GMP) were modified on multiwalled carbon nanotubes (MWNTs-GMP). Then, antibody of p24(anti p24) was coated on it to prepare MWNTs-GMP/anti p24 biomarker. Finally, the marker was absorbed on the surface of N,N'-Bis (2-hydroxy-methylene)-o-phenylenediamine copper (CuRb) modified screen-printed carbon electrodes (SPCEs) through external magnetic field in which CuRb can be employed as an electron transfer mediator and catalyst for detection of H2O2. After the immunosensor is incubated with p24 sample at room temperature for 15 min, the electron transfer access of CuRb to H2O2 is partly inhibited, which leads to a linear decrease of the catalytic efficiency to H2O2 at 300 mV in pH 7.0 PBS. Under optimal conditions, the linear range of p24 is from 0.6 to 160 mu g/L and the detection limit is 0.32 mu g/L at 3 times noise. The immunosensor was employed to determine p24 in acquired immure deficiency syndrome (AIDs) patients' serum samples and the results were consistent to the tradition ELISA method which was suitable for screen determination of trace p24 in serums of AIDs' patients.