Synthesis of a Platinum Linker Complex as a Scaffold for the Hybridization of Naturally Occurring DNA and Gold Nanoparticles

Composites of DNA and gold nanoparticles are expected to be stimuli-responsive and photo-functional materials that can synergistically utilize both the stimuli-responsiveness derived from DNA and the optical properties derived from gold nanoparticles. However, conventional methods require the bottom-up synthesis of artificial DNA modified with functional groups such as thiols that can form chemical bonds with gold nanoparticles, which limits the flexible design of the resulting composite. Therefore, we conceived the idea of introducing a “linker” that can interact with both gold nanoparticles and the bases naturally exist in DNA. The introduction of such a linker allows naturally occurring DNA, which is abundant in nature and has long strand lengths, to utilize as the multi-functional material platform. In this work, we designed and synthesized a linker complex with disulfide group and platinum(II) ion to interact with gold nanoparticles and the bases of DNA, respectively. Furthermore, the interaction between gold nanoparticles and naturally occurring DNA via the platinum linker complex was confirmed using UV–visible absorption spectroscopy.