Differential suspended single-layer graphene nanopore sensor, and preparation method therefor and use thereof

A preparation method for a differential suspended single-layer graphene nanopore sensor for a single-molecule detection, comprising:

• step 1 of providing a silicon substrate layer with a silicon dioxide layer formed on a surface of a side of the silicon substrate layer;
• step 2 of etching a side of the silicon substrate layer facing away from the silicon dioxide layer to form at least one groove at the silicon substrate layer, allowing the silicon dioxide layer located in a region of the at least one groove to suspend;
• step 3 of forming a graphene strip unit at a side of the silicon dioxide layer facing away from the silicon substrate layer, the graphene strip unit comprising two single-layer grapheme stripes arranged at an interval and stretched across the at least one groove;
• step 4 of depositing a metal electrode layer on a part of the silicon dioxide layer and the two single-layer graphene strips that are located at two sides of the at least one groove, the metal electrode layer formed at one of the two sides of the at least one groove covering the two single-layer grapheme stripes simultaneously, the metal electrode layer formed at the other one of the two sides of the at least one groove comprising two parts arranged at an interval, and each of the two parts covering one of the two single-layer graphene strips;
• step 5 of etching away the silicon dioxide layer that is exposed in the region of the at least one groove by using a hydrofluoric acid solution, allowing the two single-layer graphene strips corresponding to the region of the at least one groove to suspend;
• and
• step 6 of punching nanopores in one of the two single-layer graphene strips suspending in the at least one groove by using an ion beam to obtain the sensor.