Improving signal-to-noise performance for DNA translocation in solid-state nanopores at MHz bandwidths

Nano Lett. 2014 Dec 10;14(12):7215-20. doi: 10.1021/nl504345y. Epub 2014 Dec 1.

Abstract

DNA sequencing using solid-state nanopores is, in part, impeded by the relatively high noise and low bandwidth of the current state-of-the-art translocation measurements. In this Letter, we measure the ion current noise through sub 10 nm thick Si3N4 nanopores at bandwidths up to 1 MHz. At these bandwidths, the input-referred current noise is dominated by the amplifier's voltage noise acting across the total capacitance at the amplifier input. By reducing the nanopore chip capacitance to the 1-5 pF range by adding thick insulating layers to the chip surface, we are able to transition to a regime in which input-referred current noise (∼ 117-150 pArms at 1 MHz in 1 M KCl solution) is dominated by the effects of the input capacitance of the amplifier itself. The signal-to-noise ratios (SNRs) reported here range from 15 to 20 at 1 MHz for dsDNA translocations through nanopores with diameters from 4 to 8 nm with applied voltages from 200 to 800 mV. Further advances in bandwidth and SNR will require new amplifier designs that reduce both input capacitance and input-referred amplifier noise.

Keywords: DNA; Nanopore; TEM; capacitance; sequencing; silicon nitride.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Conductometry / instrumentation*
  • DNA / analysis*
  • DNA / chemistry*
  • DNA / genetics
  • Equipment Design
  • Equipment Failure Analysis
  • Motion
  • Nanopores / ultrastructure*
  • Nanotechnology / instrumentation*
  • Radio Waves
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Sequence Analysis, DNA / instrumentation*

Substances

  • DNA