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DNA counterion current and saturation examined by a MEMS-based solid state nanopore sensor
Hung Chang1, Bala Murali Venkatesan, Samir M Iqbal
1Birck Nanotechnology Center, School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, USA.
Biomedical Microdevices
|June 27, 2006
Summary
Ionic current pulses during DNA translocation through solid-state nanopores reveal insights into condensed counterions and dipole saturation. This study models DNA counterion current and saturation, impacting DNA sensing and molecular electronics.
Area of Science:
- Physics
- Biophysics
- Nanotechnology
Background:
- DNA translocation through solid-state nanopores is increasingly studied.
- Advancements in pore fabrication enable detailed measurements.
- Both current blockages and enhancements are observed during DNA translocation.
Purpose of the Study:
- To investigate ionic current pulses during single DNA molecule translocation.
- To explore the relationship between electric field and current direction.
- To model DNA counterion ionic current and saturation.
Main Methods:
- Fabrication of MEMS-based solid-state nanopores.
- Measurement of ionic currents during DNA translocation.
- Varying applied electric fields to analyze current pulse direction.
Main Results:
- Current pulse direction provides insight into condensed counterions.
- Demonstrated dipole saturation in single DNA molecules.
- Proposed a model for DNA counterion ionic current and saturation.
Conclusions:
- Nanopore measurements offer fundamental insights into DNA physics.
- The proposed model advances understanding of DNA counterion dynamics.
- Findings have implications for DNA sensing, delivery, conductivity, and molecular electronics.