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14:11
Quantification of Hydrogen Concentrations in Surface and Interface Layers and Bulk Materials through Depth Profiling with Nuclear Reaction Analysis
Published on: March 29, 2016
Tunnelling readout of hydrogen-bonding-based recognition
Shuai Chang1, Jin He, Ashley Kibel
1Department of Physics, Arizona State University, Tempe, Arizona 85287, USA.
Nature Nanotechnology
|May 8, 2009
Summary
Scanning tunneling microscopy can measure DNA base pair hydrogen bond strength. Guanine-cytosine pairs with three bonds are stiffer than adenine-thymine pairs with two bonds, enabling new biosensor development.
Area of Science:
- Molecular Biophysics
- Nanotechnology
- Biochemistry
Background:
- Hydrogen bonds are crucial for molecular recognition and electron transport.
- DNA base pairing, like guanine-cytosine and adenine-thymine, relies on hydrogen bonds.
- Scanning tunneling microscopy (STM) is sensitive to molecular interactions.
Purpose of the Study:
- To demonstrate that STM can quantify hydrogen bond strength in DNA base pairs.
- To investigate the role of hydrogen bonds in the mechanical and electronic properties of DNA junctions.
Main Methods:
- Forming DNA base pair junctions between a scanning tunneling microscope tip and a surface.
- Measuring the decay of tunnel current as the junction is mechanically pulled apart.
- Analyzing the relationship between hydrogen bond number and junction stiffness.
Main Results:
- STM tunnel-decay signals directly correlate with hydrogen bond strength.
- Guanine-cytosine (3 H-bonds) junctions are stiffer than adenine-thymine (2 H-bonds) junctions.
- Attractive forces dependent on hydrogen bonds influence current rise during probe approach.
Conclusions:
- STM is a viable tool for measuring hydrogen bond strength in DNA.
- Hydrogen bond number dictates mechanical properties of DNA junctions.
- These findings offer novel pathways for creating molecular recognition-based electronic sensors.
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