Sapphire Nanopores for Low-Noise DNA Sensing

Solid-state nanopores have broad applications in single-molecule biosensing and diagnostics, but their high electrical noise associated with a large device capacitance has seriously limited both their sensing accuracy and recording speed. Current strategies to mitigate the noise has focused on introducing insulating materials (such as polymer or glass) to decrease the device capacitance, but the complex process integration schemes diminish the potential to reproducibly create such nanopore devices. Here, we report a scalable and reliable approach to create nanopore membranes on sapphire with triangular shape and controlled dimensions by anisotropic wet etching a crystalline sapphire wafer, thus eliminating the noise-dominating stray capacitance that is intrinsic to conventional Si based devices. We demonstrate tunable control of the membrane dimension in a wide range from ~200 um to as small as 5 um, which corresponds to