title: Magnetic characteristics of copper ion-modified DNA thin films.
abstract: We developed a new method of fabricating a divalent copper ion (Cu(2+)) modified DNA thin film on a glass substrate and studied its magnetic properties. We evaluated the coercive field (Hc), remanent magnetization (Mr), susceptibility (χ), and thermal variation of magnetization with varying Cu(2+) concentrations [Cu(2+)] resulting in DNA thin films. Although thickness of the two dimensional DNA thin film with Cu(2+) in dry state was extremely thin (0.6 nm), significant ferromagnetic signals were observed at room temperature. The DNA thin films with a [Cu(2+)] near 5 mM showed the distinct S-shape hysteresis with appreciable high Hc, Mr and χ at low field (≤600 Oe). These were primarily caused by the presence of small magnetic dipoles of Cu(2+) coordination on the DNA molecule, through unpaired d electrons interacting with their nearest neighbors and the inter-exchange energy in the magnetic dipoles making other neighboring dipoles oriented in the same direction.
authors: Department of Physics, Sungkyunkwan University, Suwon 440-746, Korea.
authors: Sreekantha Reddy
authors: SR
authors: Dugasani
authors: Namhoon
authors: N
authors: Lee
authors: Junwye
authors: J
authors: Lee
authors: Byeonghoon
authors: B
authors: Kim
authors: Si Un
authors: SU
authors: Hwang
authors: Keun Woo
authors: KW
authors: Lee
authors: Won Nam
authors: WN
authors: Kang
authors: Sung Ha
authors: SH
authors: Park
mesh_terms: D003300:Copper / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D007477:Ions / Q000737:chemistry*; D060526:Magnetic Fields; D060328:Magnetic Phenomena; D018625:Microscopy, Atomic Force
chemical_list: D007477:Ions; D003300:Copper; D004247:DNA
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