Distinguishing Single and Double Stranded DNA Based on Solid State Nanopores

Early diagnosis of diseases requires specific detection of certain biological molecules. Here, we propose a solid-state nanopore platform based on silicon nitride, which can detect and distinguish ssDNA (22 nt) and dsDNA (22 bp). Experimental data shows that the translocation of ssDNA and dsDNA in nanopores is controlled by competition between electro-osmosis and electrophoresis. At a pore size of approximately 10 nm, ssDNA is driven by electro-osmosis through the nanopores, while dsDNA is driven by electrophoretic forces through the nanopores. The current blocking caused indicates that the current blocking amplitude caused by dsDNA passing through the nanopores is twice that of ssDNA.