Fig. 2.

The scheme illustrates the detection of the HBV genome via a voltammetric electrochemical genosensor preparation process. Present diagram represents the preparation and modification processes of gold electrode modified with molecular beacon (MB/GE) using bare GE and MB to bio-sensing of the ssDNA sequence derived from the genome of hepatitis B virus (HBV) by circular strand displacement (CSD) and rolling circle amplification (RCA) strategies mediated by a molecular beacon (MB). Hence, the target ssDNA hybridizes with the loop section of the MB/GE, while the rest of partial DNA sequences of MB hybridizes with primer DNA. In the following steps, the RCA initiates in the presence of dNTPs, Phi 29 DNA polymerase, and T4DNA ligase to produce a long DNA strand with multiple tandem-repeat sequences and this results led to detection of the induced voltammetric signals in the presence of electrochemical probe Methylene Blue. This figure is obtained with permission from Ref. [115].