ssDNA sequencing by rectification.

Fast, reliable and inexpensive DNA sequencing is an important pursuit in biotechnology with potentially profound societal impact due to its implications on personalized medicine. High resolution and specificity are key cornerstones of technological progress of DNA sequencing, currently enabled by various nanopore current measuring methods. Here we propose a rectification-based protocol for ssDNA sequencing in a nanopore with side-embedded N-terminated carbon nanotube electrodes. The rectification arises due to nucleotide-charging-induced HOMO pinning to the electrochemical potential of one of the electrodes, assisted by the electric field effect caused by dipoles at the polar bond terminated electrode ends. The proposed sequencing mechanism is sensitive, robust to molecular orientation, has high resolution, with orders of magnitude difference in amplitude between the different nucleobases. Our theoretical approach could be used to engineer the in-gap field effect by electrode termination species selection.