Amplified detection of hepatitis B virus using an electrochemical DNA biosensor on a nanoporous gold platform

In the present study, a nanoporous gold platform was applied for the amplified detection of Hepatitis B virus (HBV) by an electrochemical DNA biosensor. Ferrocene as a redox reporter was covalently attached to the DNA probe and its electrochemical signal was recorded as the biosensor response. For real samples, DNA was firstly extracted from blood of patients and then amplified by polymerase chain reaction (PCR) for 5cycles. Sensitivity of this biosensor was enhanced by using nanoporous gold electrode, therefore this sensor can discriminate the genome of HBV in real sample with low PCR cycles. By this strategy and signal amplification using nanoporous platform and covalently attached electroactive label, the biosensor can distinguish between healthy and HBV patients with limited PCR cycles. Moreover, the errors of PCR with large cycles can be disregarded. A linear dynamic range of 0.4 to 10nmol of mutant DNA was achieved, with reliable reproducibility (RSD) 8.9%.