Abstract
Deoxyribonucleic acid（DNA）has a unique helix structure showing interesting material properties, and has been implemented in optoelectronics in recent years. In this study, DNA nanocomposite consisting of gold nanoparticles dispersed in DNA biopolymer matrix was investigated and was employed for the applications in random lasers. In the first part of this work, the synthesis of gold nanoparticles and the fabrication of DNA nanocomposite were presented. Gold nanoparticles with various sizes were fabricated and its optical properties and shapes were studied. Such gold nanoparticles and DNA nanocomposite can be further applied to optoelectronics devices. In the second part of this work, random lasing emission in DNA nanocomposite was presented, where DNA nanocomposite was used as host material and Rh6G laser dye as gain medium. We investigated the random lasing emission with different sizes of gold nanoparticles, concentrations of gold nanoparticles and concentrations of Rh6G dye. Finally, the random lasing performance using DNA biopolymer as a host was compared to other host materials, such as PVA and PMMA. The experiment results suggest that larger size of gold nanoparticles in DNA nanocomposite material leads to lower threshold, which is related to the scattering cross section of gold nanoparticles and optics characteristics of surface plasmon resonance（SPR）.