Electrical properties of nanofibers and structural characterization of DNA-Au(III) complexes.
In order to realize deoxyribonucleic acid (DNA)-based molecular electronics, chemical modifications of DNA are needed to improve electrical conductivity. We developed a novel method utilizing the incorporation of Au(III) ions into DNA bases to alter their electronic properties. When Au(III) ions were incorporated proportionally into DNA bases, conductance increased up to an Au(III) content of 0.42 Au(III) ion/nucleotide. Surprisingly, electron paramagnetic resonance signals of Au(II) ions were detected at g ∼1.98, and the calculated spin number of Au(II) ions ranged from ∼10(13) to ∼10(15). The structural deformation of the DNA helix occurred when complexed with Au(III); simultaneously, the conductance of DNA-Au(III) complexes decreased when the content of Au(III) was higher than 0.42 atom/nucleotide. This observation implies that the maintenance of helical structure in the Au(III) doped state of DNA molecules is very important to the enhancement of the carrier mobility of DNA.
KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 136-701, Korea.
Young-Wan
YW
Kwon
Chang Hoon
CH
Lee
Jung-Il
JI
Jin
Jong Seung
JS
Hwang
Sung Woo
SW
Hwang
D004247:DNA / Q000737:chemistry*; D004553:Electric Conductivity; D004578:Electron Spin Resonance Spectroscopy; D006046:Gold / Q000737:chemistry*; D007477:Ions; D057139:Nanofibers / Q000737:chemistry*; D009690:Nucleic Acid Conformation
D007477:Ions; D006046:Gold; D004247:DNA