Biomedical Microdevices

, Volume 8, Issue 3, pp 263–269

DNA counterion current and saturation examined by a MEMS-based solid state nanopore sensor

  • Hung Chang
  • Bala Murali Venkatesan
  • Samir M. Iqbal
  • G. Andreadakis
  • F. Kosari
  • G. Vasmatzis
  • Dimitrios Peroulis
  • Rashid Bashir
Article

DOI: 10.1007/s10544-006-9144-x

Cite this article as:
Chang, H., Venkatesan, B.M., Iqbal, S.M. et al. Biomed Microdevices (2006) 8: 263. doi:10.1007/s10544-006-9144-x

Abstract

Reports of DNA translocation measurements have been increasing rapidly in recent years due to advancements in pore fabrication and these measurements continue to provide insight into the physics of DNA translocations through MEMS based solid state nanopores. Specifically, it has recently been demonstrated that in addition to typically observed current blockages, enhancements in current can also be measured under certain conditions. Here, we further demonstrate the power of these nanopores for examining single DNA molecules by measuring these ionic currents as a function of the applied electric field and show that the direction of the resulting current pulse can provide fundamental insight into the physics of condensed counterions and the dipole saturation in single DNA molecules. Expanding on earlier work by Manning and others, we propose a model of DNA counterion ionic current and saturation of this current based on our experimental results. The work can have broad impact in understanding DNA sensing, DNA delivery into cells, DNA conductivity, and molecular electronics.

Keywords

NanoporeDNA counterionsSingle molecule

Copyright information

© Springer Science + Business Media, LLC 2006

Authors and Affiliations

  • Hung Chang
    • 1
  • Bala Murali Venkatesan
    • 1
  • Samir M. Iqbal
    • 1
  • G. Andreadakis
    • 2
  • F. Kosari
    • 2
  • G. Vasmatzis
    • 2
  • Dimitrios Peroulis
    • 1
  • Rashid Bashir
    • 3
  1. 1.Birck Nanotechnology Center, School of Electrical and Computer EngineeringPurdue UniversityWest LafayetteUSA
  2. 2.Department of Laboratory Medicine and Pathology, Division of Experimental PathologyMayo ClinicRochesterUSA
  3. 3.Birck Nanotechnology Center, School of Electrical and Computer Engineering, Weldon School of Biomedical Engineering, School of Mechanical EngineeringPurdue UniversityWest LafayetteUSA