Translocating Single-Stranded DNA through Crystalline Graphene Nanopores

Abstract

Here, we report the successful translocation of single-stranded DNA through graphene nanopores which normally is plagued by sticking of the bases on the graphene, which we have now solved (we will reveal the details of this crucial issue at the BPS meeting). We recently developed a simple and fast water-based method for transferring graphene onto arbitrary surfaces, with micrometer alignment precision. Using this method, we fabricated ranges of graphene membranes in which nanometer sized pores were sculpted. Under an electron beam, we discovered that graphene undergoes a temperature sensitive self-repair mechanism that allows damage-free atomic scale sculpting of perfectly crystalline graphene nanostructures, such as nanopores with crystalline edges. When mounted between two flow chambers containing buffered DNA, these extremely thin nanopores were used to detect DNA molecules and very recently single-stranded strands of DNA. As individual DNA molecules translocate through the pore, characteristic temporary conductance changes were observed in the ionic current through the nanopore, setting the stage for future single-molecule genomic screening devices.