The invention discloses a method for preparing a
graphene nanobelt-
DNA sensor based on a template method and a method for detecting mercury ions, and the method for preparing the
graphene nanobelt-
DNA sensor based on the template method comprises the following steps: S1, preparing a
graphene substrate; s2, positioning and fixing a template; s3,
oxygen plasma etching and template removal are carried out; s4, carrying out
electrode evaporation; s5, activating the sensor and connecting with the
DNA; the graphene nanobelt is prepared by adopting a template method, a
silicon nanowire or a
carbon nanotube is selected as a template, an
oxygen plasma etching technology is combined, the morphology and size of the graphene nanobelt can be accurately controlled, a large number of carboxyl groups are introduced into the edge of the etched graphene nanobelt, and sufficient active sites are provided for subsequent stable connection with DNA (
Deoxyribose Nucleic Acid); meanwhile, by optimizing the
concentration ratio of the EDC / NHS activating agent, the
DNA concentration and the
reaction temperature, the connection efficiency of the graphene nanobelt and the DNA is remarkably improved, and the
electrical stability of the sensor is ensured.