(327k) DNA Origami for Nanoparticle Organization and Plasmonic Applications

The unique properties of gold nanoparticles (AuNPs) allow for a wide range of biologic and electronic applications. AuNPs can quench fluorophores near their surface through Förster or fluorescence resonance energy transfer (FRET), are useful as surface-enhanced Raman spectroscopy (SERS) substrates and have easily observed changes in surface plasmon resonance (SPR). These unique properties of AuNPs make them suitable for a variety of applications such as improved localized heating and energy propagation in waveguide models. Another important property of AuNPs, is the ease with which DNA can be conjugated to their surface which allows for integration with DNA origami. DNA origami nanostructures allow for precise organization and dynamic interactions of nanoparticles. The dynamic nature of DNA origami allows us to study the fundamental science that underlies the interactions between AuNPs.

We developed DNA origami hinges that can bind AuNPs with different strength on either arm. Different single stranded (ss) DNA overhangs are available for binding on each arm of the hinge that are complimentary to ssDNA conjugated AuNPs. Longer strands form a stronger bond which will have a different melting temperature allowing the hinge to open and close without releasing the AuNP completely. FRET reporters were used to study the kinetics of hinge actuation with bulk heating and laser excitation. These results have led to the development of higher order hinge structures that allow for the organization of multiple AuNPs into waveguide structures.