Spatially Multiplexed Single-molecule Translocations through a Nanopore at Controlled Speeds

Abstract

AbstractNanopores are one of the most successful label-free single-molecule techniques with several sensing applications such as biological screening, diagnostics, DNA and protein sequencing1–4. In current nanopore technologies, stochastic processes influence both the selection of the translocating molecule, translocation rate and translocation velocity5,6. As a result, single-molecule translocations are difficult to control spatially and temporally. Here we present a novel method where we engineer precise spatial and temporal control into the single-molecule experiment. We use a glass nanopore mounted on a 3D nanopositioner to spatially select molecules, deterministically tethered on a glass surface, for controlled translocations. By controlling the distance between the nanopore and the glass surface, we can actively select the region of interest on the molecule and scan it a controlled number of times and at controlled velocity. Decreasing the velocity and averaging thousands of consecutive readings of the same molecule increases the signal-to-noise ratio (SNR) by two orders of magnitude compared to free translocations. We applied our method to various DNA constructs, achieving down to single nucleotide gap resolution. The spatial multiplexing combined with the sub-nanometer resolution could be used in conjunction with micro-array technologies to enable screening of DNA, improving point of care devices, or enabling high-density, addressable DNA data storage.