Self‐Assembly of DNA Nanostructures in Different Cations

Abstract The programmable nature of DNA allows the construction of custom‐designed static and dynamic nanostructures, and assembly conditions typically require high concentrations of magnesium ions that restricts their applications. In other solution conditions tested for DNA nanostructure assembly, only a limited set of divalent and monovalent ions are used so far (typically Mg 2+ and Na + ). Here, we investigate the assembly of DNA nanostructures in a wide variety of ions using nanostructures of different sizes: a double‐crossover motif (76 bp), a three‐point‐star motif (~134 bp), a DNA tetrahedron (534 bp) and a DNA origami triangle (7221 bp). We show successful assembly of a majority of these structures in Ca 2+ , Ba 2+ , Na + , K + and Li + and provide quantified assembly yields using gel electrophoresis and visual confirmation of a DNA origami triangle using atomic force microscopy. We further show that structures assembled in monovalent ions (Na + , K + and Li + ) exhibit up to a 10‐fold higher nuclease resistance compared to those assembled in divalent ions (Mg 2+ , Ca 2+ and Ba 2+ ). Our work presents new assembly conditions for a wide range of DNA nanostructures with enhanced biostability.