Electrochemical sensor based on direct electron transfer of HIV-1 virus at Au nanoparticle modified ITO electrode

In this study, for the first time, an electrochemical detection method was proposed to detect direct electron transfer signal from HIV-1 Virus. Au nanoparticles were fabricated on the Indium Tin Oxide coated glass (ITO) electrode by electrochemical deposition to improve the surface area to provide better electron-transfer kinetics, and higher background charging current. On the Au nanoparticle modified ITO electrode, antibody fragment was immobilized by self-assembly method with gold-thiol interaction and different concentrations of HIV-1 Virus like particles (VLPs) were applied for the direct determination. Due to the advantage of fabricated Au nanoparticle's excellent electrical and mechanical properties, HIV-1 VLPs were successfully detected from 600 fg/mL to 375 pg/mL. Furthermore, since the proposed electrochemical virus sensor is designed for direct determination without any labeling structure, the electrochemical communication between redox target and electrode surface will reduce interference reactions and simplifies the detection system with small amount of reagent and better stability. Therefore, highly sensitive virus sensor was developed to detect HIV-1 Virus in a label free system.