A biosensor device,built from graphene nanoribbons(GNRs) with nanopores,was designed and studied by firstprinciples quantum transport simulation.We have demonstrated the intrinsic transport properties of the device and the effect of different nucleobases on device properties when they are located in the nanopores of GNRs.It was found that the device’s current changes remarkably with the species of nucleobases,which originates from their different chemical compositions and coupling strengths with GNRs.In addition,our first-principles results clearly reveal that the distinguished ability of a device’s current depends on the position of the pore to some extent.These results may present a new way to read off the nucleobases sequence of a single-stranded DNA(ssDNA) molecule by such GNRs-based device with designed nanopores A biosensor device, built from graphene nanoribbons (GNRs) with nanopores, was designed and studied by firstprinciples quantum transport simulation. We have demonstrated the intrinsic transport properties of the device and the effect of different nucleobases on device properties when they are located in the nanopores of GNRs.It was found that the device’s current changes remarkably with the species of nucleobases, which originates from their different chemical compositions and coupling strengths with GNRs.In addition, our first-principles results clearly reveal that the distinguished ability of a device’s current depends on the position of the pore to some extent. this result may present a new way to read off the nucleobases sequence of a single-stranded DNA (ssDNA) molecule by such GNRs-based devices with designed nanopores