PNNL

Abstract

Building plasmonic nanostructures using biomolecules as scaffolds has shown great potential for attaining tunable light absorption and emission via precise spatial organization of optical species and antennae. Here we report bottom-up assembly of hierarchical plasmonic nanostructures using DNA origami tiles and MS2 virus capsids. These serve as programmable scaffolds that provide molecular level control over the distribution of fluorophores and nm-scale control over their distance from a gold nanoparticle antenna. While previous studies on DNA origami assembly of plasmonic nanostructures focused on the distance-dependent response of single fluorophores, these hybrid nanostructures enable us to investigate the plasmonic response of the entire ensemble of fluorescent molecules organized on the virus scaffold. By combining finite-difference time-domain (FDTD) numerical simulations with atomic force microscopy (AFM) and correlated scanning confocal fluorescence microscopy, we show that the dye molecule ensemble can effectively suppress the fluorescence quenching in the single molecule quenching regime. This bio-inspired approach to assembling plasmonic nanostructures paves the way for exploring new designs to achieve controlled light harvesting and energy transfer for optical and optoelectronic applications.