Roles of anionic and cationic template components in biomineralization of CdS nanorods using self-assembled DNA-membrane complexes

Complexes of anionic DNA and cationic liposomes self-assemble into a multilamellar structure where two-dimensional lipid sheets confine a periodic one-dimensional lattice of parallel DNA chains, between which Cd2+ ions can condense, and be subsequently reacted with H2S to form CdS nanorods. In this work, we identify the synergistic roles of the anionic and cationic components within the DNA-membrane template; DNA is highly anionic and condenses the Cd2+ ions, while the cationic membrane modulates the concentration of condensed Cd2+ ions to control the final CdS nanorod dimensions. Due to the strong electrostatic interactions between the DNA sugar-phosphate backbone and the Cd2+ ions, crystallographic control of CdS nanostructures is possible using these simple DNA-membrane templates, which we demonstrate using nanobeam electron diffraction experiments on individual templated CdS nanorods.