Voltage-driven translocation of DNA through a high throughput conical solid-state nanopore

PLoS One. 2012;7(9):e46014. doi: 10.1371/journal.pone.0046014. Epub 2012 Sep 24.

Abstract

Nanopores have become an important tool for molecule detection at single molecular level. With the development of fabrication technology, synthesized solid-state membranes are promising candidate substrates in respect of their exceptional robustness and controllable size and shape. Here, a 30-60 (tip-base) nm conical nanopore fabricated in 100 nm thick silicon nitride (Si(3)N(4)) membrane by focused ion beam (FIB) has been employed for the analysis of λ-DNA translocations at different voltage biases from 200 to 450 mV. The distributions of translocation time and current blockage, as well as the events frequencies as a function of voltage are investigated. Similar to previously published work, the presence and configurations of λ-DNA molecules are characterized, also, we find that greater applied voltages markedly increase the events rate, and stretch the coiled λ-DNA molecules into linear form. However, compared to 6-30 nm ultrathin solid-state nanopores, a threshold voltage of 181 mV is found to be necessary to drive DNA molecules through the nanopore due to conical shape and length of the pore. The speed is slowed down ∼5 times, while the capture radius is ∼2 fold larger. The results show that the large nanopore in thick membrane with an improved stability and throughput also has the ability to detect the molecules at a single molecular level, as well as slows down the velocity of molecules passing through the pore. This work will provide more motivations for the development of nanopores as a Multi-functional sensor for a wide range of biopolymers and nano materials.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacteriophage lambda / chemistry
  • DNA, Viral / chemistry*
  • Electricity
  • Membranes, Artificial
  • Motion
  • Nanopores*
  • Nanotechnology
  • Silicon Compounds / chemistry*

Substances

  • DNA, Viral
  • Membranes, Artificial
  • Silicon Compounds
  • silicon nitride

Grants and funding

The authors are grateful for financial support from National Natural Science Foundation of China (61071050); international cooperation project from the Ministry of Science and Technology of China (2009 DFA32750); the Ministry of Education major project(200967); the Open Project of State Key Laboratory of Bioelectronics of Southeast University (2011E14); the China Postdoctoral Science Foundation (20110491339); Chinese Postdoctoral Fund (No. 2011M500081); Natural Science Foundation of China (61101056). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.