Core solution: a strategy towards gold core/non-gold shell nanoparticles bearing strict DNA-valences for programmable nanoassembly

DNA nanotechnology offers a massively parallel process to build innovative nanomaterials from the bottom up with excellent structural programmability and functional tunability. So far most of the successes have been restricted to gold nanoparticles (AuNPs) based on an earlier breakthrough in controlling the number (valence) of DNA ligands on an AuNP. However, attempts to incorporate non-gold metal materials have met various difficulties. To address this challenge, we herein develop a method to achieve reliable DNA-conjugations and gel electrophoretic valence separations of Au@Ag and Au@Pd core–shell nanoparticles. The existence of a gold core allows us to control the structure, composition, and colloidal properties of the nanoparticles, which is critical to achieving compatibility with gel electrophoresis. The resulting bionanoconjugates with strictly defined DNA valences function very well in DNA-programmable nanoassembly towards various possible applications in the future.