DNA engineered tri-functional Ni-Au nano-chain: understanding of its formation and novel magnetic properties.

A plausible mechanism have been proposed here on the formation of chain like structure of Ni-Au-DNA (deoxyribo nucleic acid) composite which has been synthesized by simple wet-chemical process. The composite has been designed in such a fashion that it can be easily probed by optically, electrically and magnetically. In this paper, we are reporting its structural and physical properties in detail. Optical properties have been probed by Circular Dichroism (CD) which indicates no denaturization or melting of DNA even after formation of the composite structure. X-ray diffraction (XRD) study and Fourier transform infrared spectroscopy (FTIR) analysis show the nickel and gold are fcc in phase and bound to DNA through chemical bond, respectively. The composite shows room temperature semiconductor behavior. Temperature dependent magnetization and magnetic hysteresis loops are investigated in detail. The detail study of the composite indicates a possibility of its capability to be used in bio-devices. Furthermore, the tri-functionality of the composite will open-up its versatile applications.