▎ 摘　　要

Graphene nanopore based sensor devices have shown great potential for the detection of DNA. To understand the fundamental aspects of DNA translocation through a graphene nanopore, in this work, molecular dynamics (MD) simulations and potential of mean force (PMF) calculations were carried out to investigate the impact of the number of graphene layers of small nanopores (2-3 nm) on DNA translocation. It was observed that the ionic conductance was sensitive to the number of graphene layers of open-nanopores, and the probability of DNA translocation through graphene nanopores was related to the thickness of the graphene nanopores. MD simulations showed that DNA translocation time was most sensitive to the thickness of graphene nanopores of 2.4 nm aperture, and the observed free energy barrier of PMFs and the profile change revealed the increased retardation of DNA translocation through bilayer graphene nanopores as compared to that through monolayer graphene nanopores.