The invention discloses a probe for detecting HBV-
DNA as well as application and a method thereof, the probe is a padlock probe, and the padlock probe comprises an RCA annular template region and an HBV-
DNA recognition region. The preparation method of the
working electrode comprises the following steps: incubating padlock probe
DNA (
Deoxyribose Nucleic Acid) and HBV (
Hepatitis B
Virus)-DNA; then
exonuclease III is added for incubation, and then thermal inactivation treatment is carried out; adding PolyT-primer and
escherichia coli
DNA ligase, mixing, incubating, and carrying out thermal inactivation treatment; then adding dNTP (
deoxyribonucleoside triphosphate) without dATP (
deoxyadenosine triphosphate) and phi29 DNA (deoxyribonucleic acid)
polymerase, incubating, and carrying out thermal inactivation treatment; and after the incubation sample liquid is cooled, incubating by using MB (ZIF)-90, then centrifugally collecting the supernatant, transferring the supernatant to the
electrode modified by MX / MWCNTs, and after incubation, washing away MB which is not adsorbed on the
electrode to obtain the
working electrode. The method is simple to operate, rapid in detection and high in sensitivity.