A Platform for High-Bandwidth, Low-Noise Electrical Nanopore Sensing with Thermal Control

Abstract

Solid-state nanopores are an emerging class of single-molecule detectors that provide information about molecular identity via the analysis of transient fluctuations in the ionic current flowing across a nanoscale pore in a thin membrane. The transport of biomolecules across a pore is a key step in nanopore-based sensing of DNA, RNA and proteins. The dynamics of biomolecular transport are complex and depend on the strength of many interactions, which can be tuned with temperature. However, temperature is rarely controlled during solid-state nanopore experiments because of the added electrical noise from the temperature control and measurement systems, greatly reducing the signal-to-noise ratio when detecting individual molecules. So far, the use of electric-based heating and cooling strategies has limited the recording bandwidth to the kHz range, restricting the studies to long polymers translocating via the pore relatively slowly. Yet, many molecules translocate through the pore orders of magnitude faster. This research presents the development and testing of an instrument to allow low-noise electrical recording of nanopore signals at MHz bandwidth as a function of temperature. Initial experiments using this custom-built instrument for the study of linear DNA polymers confirm previously observed translocation behaviours, while providing a higher temporal resolution. Overall results show that high-speed nanopore experiments are possible while controlling the temperature up to 70 °C, opening up exciting opportunities to study the unfolding of proteins toward single-molecule protein sequencing and the passage of DNA nanostructures for different bioassays. Future work will focus on realizing microfluidic flow cells and nanopore performance at higher temperature for longer recording times.