Regular nanofluidic sieving structures are emerging as rapid and compatible on-chip techniques for biomolecular separation. Although the current nanofluidic sieving devices, mostly based on three-dimensional nanostructures, have achieved a separation resolution of ∼20 nm, it is still far away from single-nucleotide resolution. Using all-atom molecular dynamics simulations, here we demonstrate a two-dimensional (2D) nanofluidic sieve consisting of an in-plane graphene (GRA)/hexagonal boron nitride (h-BN) nanoarray, which enables ultrahigh resolution in the successful separation of four types of single nucleotides. The alternating GRA and h-BN stripes can create size-dependent energy barriers for adsorbed nucleotides, which provide a strong modulation for their mobility, thus causing distinct band separations on the 2D surface. We further show that this 2D sieve is particularly sensitive when the sample dimensions are within the range from a half period to one period of the nanoarray. This 2D sieving structure may shed light on the development of lab-on-a-chip sequencing in the future.
Keywords: graphene; heterostructure; hexagonal boron nitride; molecular dynamics; nanoarray; single-nucleotide separation.