Magnetic Properties of the DNA-Quaternary Ammonium Surfactant Complexes Studied by EMR Spectroscopy and SQUID Measurement
Abstract
Due to their unique chemical structures and versatile functionalities associated with their structural characteristics many research groups are studying the materials science aspects of natural and synthetic DNA. In particular, interest in nanoscience and nanotechnology is accelerating the exploration of DNA for various properties such as electrical conductivity electron or hole transport and optical properties. In contrast, study on the magnetic properties of DNA is still in the infant stage. Recently, we reported for the first time that natural dsDNA in dry state (A-DNA) showed an extremely broad electron magnetic resonance (EMR) signal as well as an S-shaped magnetization-magnetic field (M-H) curve in SQUID measurements. The broad EMR signal was interpreted as a cyclotron resonance (CR), which is possible only when the double helical structure of each dsDNA coherently couples throughout the elementary fibrils resulting in the formation of lateral loop currents responsible for the S-shaped M-H curves in SQUID measurements. Both the EMR signals and the S-shaped magnetizations are found to be strongly correlated to each other. Assuming that the fibrillar dsDNA are in a morphologically heterogeneous structure, formation of such loop currents by the external field must be much more favored in ordered regions than in amorphous ones. In other word, the dsDNA can not only be a molecular solenoid in the single molecular level, but also can be a ferromagnetic in the well ordered regions due to coherently coupled bundles of DNA molecular solenoids. Therefore, if one introduces a magnetic dipole into the DNA molecular solenoid, a strong enhancement of DNA susceptibility is expected to occur as in an electrical solenoid with a magnetic bar. In this respect, we tried to insert various stable radicals into the dsDNA and succeeded in observing strong enhancements in their magnetic susceptibilities.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 24, 2008
- Accession Number
- ADA487055
Entities
People
- Chang H. Lee
- Dong H. Choi
- Eui D. Do
- Eui K. Koh
- James G. Grote
- Jung-il Jin
- Young-wan Kwon
Organizations
- Korea University