A highly sensitive and stable electrochemical HBV DNA biosensor based on ErGO-supported Cu-MOF

It is still a very challenging work to develop new and more effective methods for detecting Hepatitis B virus (HBV). In this work, a new simple electrochemical biosensor with high sensitivity and stability was constructed for detecting HBV DNA by combining the electroactive Cu-MOF as a signal nanoprobe and multi-site matrix and electroreduced graphene oxide (ErGO) as signal amplification material. Cu-MOF exhibits good affinity to probe DNA through covalent attachment, which can further stabilize DNA probe. The probe DNA density and the hybridization efficiency of this electrochemical DNA biosensor was 9.48 × 1013 molecules cm−2 and 89.9%, respectively. Under optimal conditions, the electrochemical DNA biosensor had an excellent performance toward HBV DNA determination with a wide linear range of 50.0 fM to 10.0 nM, and a low limit of detection (LOD) of 5.2 fM, more sensitive than other reported electrochemical HBV DNA biosensors. Moreover, the new sensor was used to measure HBV DNA in human serum and urine samples with sound results. This work also provides some insights for the construction of other electrochemical DNA biosensors.