Multiplex electrochemiluminescence DNA sensor for determination of hepatitis B virus and hepatitis C virus based on multicolor quantum dots and Au nanoparticles

In this work, a novel multiplex electrochemiluminescence (ECL) DNA sensor has been developed for determination of hepatitis B virus (HBV) and hepatitis C virus (HCV) based on multicolor CdTe quantum dots (CdTe QDs) and Au nanoparticles (Au NPs). The electrochemically synthesized graphene nanosheets (GNs) were selected as conducting bridge to anchor CdTe QDs₅₅₁-capture DNA_HBV and CdTe QDs₆₀₇-capture DNA_HCV on the glassy carbon electrode (GCE). Then, different concentrations of target DNA_HBV and target DNA_HCV were introduced to hybrid with complementary CdTe QDs-capture DNA. Au NPs-probe DNA_HBV and Au NPs-probe DNA_HCV were modified to the above composite film via hybrid with the unreacted complementary CdTe QDs-capture DNA. Au NPs could quench the electrochemiluminescence (ECL) intensity of CdTe QDs due to the inner filter effect. Therefore, the determination of target DNA_HBV and target DNA_HCV could be achieved by monitoring the ECL DNA sensor based on Au NPs-probe DNA/target DNA/CdTe QDs-capture DNA/GNs/GCE composite film. Under the optimum conditions, the ECL intensity of CdTe QDs₅₅₁ and CdTe QDs₆₀₇ and the concentration of target DNA_HBV and target DNA_HCV have good linear relationship in the range of 0.0005–0.5 nmol L⁻¹ and 0.001–1.0 nmol L⁻¹ respectively, and the limit of detection were 0.082 pmol L⁻¹ and 0.34 pmol L⁻¹ respectively (S/N = 3). The DNA sensor showed good sensitivity, selectivity, reproducibility and acceptable stability. The proposed DNA sensor has been employed for the determination of target DNA_HBV and target DNA_HCV in human serum samples with satisfactory results.