Large-Scale Fabrication of Copper-Ion-Coated Deoxyribonucleic Acid Hybrid Fibers by Ion Exchange and Self-Metallization.

It has been a challenge to achieve deoxyribonucleic acid (DNA) metallization and mass production with a high quality. The main aim of this study was to develop a large-scale production method of metal-ion-coated DNA hybrid fibers, which can be useful for the development of physical devices and sensors. Cetyltrimethylammonium-chloride-modified DNA molecules (CDNA) coated with metal ions through self-metallization exhibit enhanced optical and magnetic properties and thermal stability. In this paper, we present a simple synthesis route for Cu-coated CDNA hybrid fibers through ion exchange followed by self-metallization and analyze their structural and chemical composition (by X-ray diffraction (XRD), high-resolution field emission transmission electron microscopy (FETEM), and energy-dispersive X-ray spectroscopy (EDS)) and optical (by ultraviolet (UV)-visible absorption, Fourier transform infrared (FTIR), and X-ray photoelectron spectroscopies (XPS)), magnetic (by vibrating-sample magnetometry), and thermal (by a thermogravimetric analysis) characteristics. The XRD patterns, high-resolution FETEM images, and selected-area electron diffraction patterns confirmed the triclinic structure of Cu in CDNA. The EDS results revealed the formation of Cu-coated CDNA fibers with a homogeneous distribution of Cu. The UV-vis, FTIR, and XPS spectra showed the electronic transition, interaction, and energy transfer between CDNA and Cu, respectively. The Cu-coated CDNA fibers exhibited a ferromagnetic nature owing to the presence of Cu. The magnetization of the Cu-coated CDNA fibers increased with the concentration of Cu and decreased with the increase in temperature. Endothermic (absorbed heat) and exothermic (released heat) peaks in the differential thermal analysis curve were observed owing to the interaction of Cu with the phosphate backbone.