A visual method for determination of hepatitis C virus RNAs based on a 3D nanocomposite prepared from graphene quantum dots

Sensitive and specific assay of hepatitis C virus (HCV) RNA has a great clinical significance for the diagnosis of hepatitis C in window period. A colorimetric assay is described for determination of the RNA of hepatitis C virus. The method is based on the in situ synthesis of graphene quantum dot-silver nano-composites (GQD/Ag NCs), magnetic separation and catalyzed hairpin assembly reaction (CHA). The silver component of GQD/Ag NCs react with H2O2 generated by glucose oxidase, which are induced via CHA. Then the light-yellow solution turns into colorless transparent in the presence of the target RNAs. The method has a linear response in the 25–500 pM RNA concentration range, and the detection limit is 24.84 pM. The method is simple, stable and sensitive and might be extend to the assay of other RNA viruses. The retro-transcription free and visual distinguishable properties endow this strategy a promising application in the screening of HCV. [Display omitted] •A retro-transcription free RNA assay strategy is proposed based on graphene quantum dot-silver nano-composites (GQD/Ag NCs).•The assay of Hepatitis C virus (HCV) RNA is visible via dissolution of GQD/Ag NCs by the H2O2 generated from glucose oxidase.•The strategy is able to sensitively detect HCV RNA over a wide linear range with a detection limit of 24.84 pM.