Label-free RNA-based electrochemical nanobiosensor for detection of Hepatitis C

Abstract

In this study, an ultrasensitive label-free nanobiosensor for detecting the Hepatitis C virus (HCV) RNA was fabricated, without the need for target denaturation, by using an RNA oligomer as a probe. The biosensor was prepared by electrodeposition of the copper oxide (Cu2O) and gold nanoparticles (AuNPs) on the nitrogen-doped graphene (NG) coated fluorine-doped tin oxide electrode (FTOE). The thiolated complementary probe of RNA virus was adsorbed on the AuNPS through monolayer self-assembly (SAM), after that, the RNA target of HCV virus binds to its complementary sequence which leads to a significant change in differential pulse voltammetry (DPV) response of the probe in the presence of Fe(CN)63−/4− as redox sensing probe. Various important parameters were optimized and at optimum conditions, the nanobiosensor had a wide dynamic range (1 × 10−15–1 × 10−6 mol. L−1) with a very low detection limit of 1 × 10−15 mol. L−1. The biosensor was successfully evaluated in the blood real samples and according to its good selectivity, wide linear range, acceptable reproducibility, and repeatability; the proposed biosensor has a suitable ability for detection of the HCV RNA in clinical applications.