Plasmid Hiv P24 Gene Detection On Mercury Film Electrode Using Osmium Labelling

The early detection of HIV-positive individuals before infecting healthy individuals is the basic principle to fight against AIDS. Although a lot of methods has been developed to detect HIV, electrochemistry is a promising tool thanks to its high sensitivity, low cost, ease of use and mostly no antibody-based detection. The aim of our study was to perform the electrochemical detection of HIV p24 gene for capsid protein. We utilized the ability of osmium tetroxide bipyridyl (OsO4(bpy)) to create the complex with thymine and used it to label the oligonucleotide complementary to the p24. We also used the thiolated oligonucleotide probe to anchor the labelled p24 gene to the magnetic particle, which served to isolate the construct from the solution of non-anchored molecules. The detection of p24 gene was performed on the mercury film glassy-carbon electrode by the adsorptive transfer method using difference pulse voltammetry. The best mercury film on the surface of glassy carbon working electrode was received using KNO3 as supporting electrolyte and by the set of potential -0.9 V for 300 s. We showed that also the femtomole amount of p24 gene within linear plasmide can be absorbed to the electrode surface and detected.