A system of controlled translocation of macromolecules by gel electrophesis employs a funnel nanopore structure. A graphene portion is attached to a porous material layer including funnel-shaped pores such that the graphene portion blocks the side of the porous material layer having openings for smaller pores. A pair of electrical contacts is formed on the graphene portion. A dielectric material layer may be deposited to hold the graphene portion in place. A nanoscale hole is formed through the dielectric material layer and the graphene portion to provide a smallest opening in a funnel nanopore structure. The funnel nanopore structure is placed within a capsule configured for gel electrophoresis. A linear chain of molecules can pass through a funnel-shaped pore and the nanoscale hole during the gel electrophoresis. A graphene nanopore detector allows measurement of blockage current for sufficient resolution of base pairs in DNA's.