A novel method to realize the transition from silver nanowires to nanoplates based on the degradation of DNA

Silver "nano-necklaces" and nanoplates in DNA/Tris-EDTA (TE) solution are prepared using hydrothermal method. The nano-necklaces are composed of many spherical silver nanoparticles which are joined together by the DNA chain. Further the transition from silver nano-necklaces to triangular and hexagonal nanoplates is realized based on the degradation of DNA. Transmission electron microscopy, selected area electron diffraction, ultraviolet-visible spectroscopy, X-ray diffraction, and agarose gel electrophoresis are used to characterize silver nanoparticles and the change of DNA structure. The results show that TE acts as not only the buffer solution but also the reducing agent. DNA serves as templates to offer the nucleation sites and induce the growth of silver nanostructures. Hydrothermal process provides high temperature and pressure to activate the reducing property of TE and denature or degrade DNA molecules. The formation mechanism of silver nano-necklaces and nanoplates has also been studied.