New Technique of DNA Sensing: Nanoribbon Transverse Electrodes

The technique of DNA sensing by electrophoretically driving it through solid-state nanopores is promising to reach the goal of rapid sequencing of individual human genomes. This approach can allow for the label-free, amplification-free analysis of nucleic acids as either single stranded DNA or double stranded DNA. Molecules ranging in length from single nucleotides to kilobase-pair can potentially be analyzed with nanometerresolution.However, the standard 2-terminal nanopore sensing method also possesses disadvantages, as the measurement resolution does not allow sensing of individual nucleobases. In order to eliminate this disadvantage, modification of the nanopore sensing technique has been proposed theoretically [1, 2]. We are pursuing the structure of a graphene nanoribbon with an embedded nanopore as a transverse electrode. A unique change of the transverse current for each nucleobase could allow discrimination between different types of nucleotides.The graphene nanoribbons are fabricated on a suspended stacked graphene/dielectric nanocomposite membrane. The stacked membrane was implemented according to the method described recently [3]. The top graphene layer was patterned by e-beam lithography in a 2 μm long x 30 nm wide nanoribbon. We will report on the transport measurements in air and in buffer solution with and without the embedded nanopore within the graphene nanoribbon.[1] T. Nelson, B. Zhang, and O.V. Prezhdo, Nano Lett. 10, 3237 (2010).[2] K.K. Saha, M. Drndic, B.K. Nikolic, arXiv:1108.3801v1 (2011).[3] B. M. Venkatesan, D. Estrada, S. Banerjee, X. Jin, V. E. Dorgan, M.-H. Bae, N. Aluru, E. Pop, and R. Bashir, submitted, (2011).