A graphene nanopore sensor comprising: a support frame including a window there through: a single-layer graphene membrane outstretched across the support frame window without a surface layer on the graphene membrane and without a support for the graphene membrane across the support frame window, the graphene membrane including a nanopore extending through a thickness of the graphene membrane from a first graphene membrane surface to a second graphene membrane surface opposite the first graphene membrane surface; a connection from the first graphene membrane surface to a first reservoir to provide, at the first graphene membrane surface, a species in an ionic solution to the nanopore; a connection from the second graphene membrane surface to a second reservoir to collect the species and ionic solution after translocation of the species and ionic solution through the nanopore from the first graphene membrane surface to the second graphene membrane surface; and an electrical circuit connected on opposite sides of the nanopore to measure flow of ionic current through the nanopore in the graphene membrane. a support frame including a window there through: a single-layer graphene membrane outstretched across the support frame window without a surface layer on the graphene membrane and without a support for the graphene membrane across the support frame window, the graphene membrane including a nanopore extending through a thickness of the graphene membrane from a first graphene membrane surface to a second graphene membrane surface opposite the first graphene membrane surface; a connection from the first graphene membrane surface to a first reservoir to provide, at the first graphene membrane surface, a species in an ionic solution to the nanopore; a connection from the second graphene membrane surface to a second reservoir to collect the species and ionic solution after translocation of the species and ionic solution through the nanopore from the first graphene membrane surface to the second graphene membrane surface; and an electrical circuit connected on opposite sides of the nanopore to measure flow of ionic current through the nanopore in the graphene membrane. a single-layer graphene membrane outstretched across the support frame window without a surface layer on the graphene membrane and without a support for the graphene membrane across the support frame window, the graphene membrane including a nanopore extending through a thickness of the graphene membrane from a first graphene membrane surface to a second graphene membrane surface opposite the first graphene membrane surface; a connection from the first graphene membrane surface to a first reservoir to provide, at the first graphene membrane surface, a species in an ionic solution to the nanopore; a connection from the second graphene membrane surface to a second reservoir to collect the species and ionic solution after translocation of the species and ionic solution through the nanopore from the first graphene membrane surface to the second graphene membrane surface; and an electrical circuit connected on opposite sides of the nanopore to measure flow of ionic current through the nanopore in the graphene membrane.