Development of an ultrasensitive electrochemical genosensor for detection of HIV-1 pol gene using a gold nanoparticles coated carbon paste electrode impregnated with lead ion-imprinted polymer nanomaterials as a novel electrochemical probe

In this work, we developed a simple and label-free voltammetric genosensor to determine the HIV-1 pole gene by using lead ion-imprinted polymer (Pb-IIP) nanoparticles as a novel electrochemical probe. For this purpose, a carbon paste electrode (CPE) was impregnated with lead ion-imprinted polymer nanoparticles. Lead ions were reduced and accumulated onto the surface of CPE at − 1.0 V vs. Ag/AgCl and, then, Au nanoparticles (AuNPs) were electrochemically deposited on the surface of Pb-IIP-CPE. The modified AuNPs/Pb-IIP-CPE electrode showed a well-defined lead oxidation peak with excellent stability and reproducibility. Finally, the thiol-DNA probe of HIV-1 pole gene was immobilized on the surface of the modified electrode through a self-assembly method. Due to the blocking of lead electron transfer at the electrode surface with the probe DNA immobilization, the Pb oxidation peak current was decreased. In the end, upon the hybridization of probe DNA with the target DNA, the response current of the electrochemical probe was further decreased. Under optimum conditions, the developed genosensor showed a linear detection range from 1 fM to 0.1 nM, with a detection limit of 0.3 fM (S/N = 3).