Dynamics of Reconfigurable Plasmonic Metamolecules Characterized by High-Throughput Time-Resolved Circular Differential Scattering.

Abstract

Characterization of the dynamics of individual reconfigurable chiral plasmonic nanostructures (metamolecules) in various local environments provides critical information toward understanding the principles and mechanisms involved in designing and constructing metamolecules. However, time-resolved statistical analysis of transition trajectories is required at the single-metamolecule level. Therefore, we developed a high-throughput time-resolved circular differential scattering (TRCDS) method for characterizing dynamic processes in single metamolecules immobilized on a substrate. This method allowed us to perform time-resolved trajectory measurements during the conformational transition of individual reconfigurable plasmonic metamolecules between two enantiomeric states, driven by the hybridization of single DNA strands <i>in situ</i> in an aqueous environment. High-throughput optical characterization supported a statistical analysis based on simultaneous measurements of hundreds of reconfigurable metamolecules with slight differences in their individual structures and local environments, within the field-of-view of the microscope. Statistical analysis revealed a transition path time τ_TP = 123.7 ms for the conformational transition. Engineering of the dynamic reconfiguration of metamolecules was demonstrated by varying the dynamic DNA strands from 8 to 11 and 14 nucleotides, resulting in an increased stability of the enantiomeric states. Our study enables the dynamic manipulation of reconfigurable plasmonic nanostructures and the rational construction of smart systems.