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.