Albany 2013: Book of Abstracts
June 11-15 2013
©Adenine Press (2012)
Sculpting Light with DNA Origami
We used the DNA origami method (Rothemund, 2010) for the fabrication of self-assembled nanoscopic materials (Seeman, 2010). In DNA origami, a virus-based 8 kilobase-long DNA single-strand is folded into shape with the help of ~ 200 synthetic oligonucleotides. The resulting DNA nanostructures can be designed to adopt any three-dimensional shape and can be addressed through DNA-hybridization or chemical modification with nanometer-precision. We have realized complex assemblies of nanoparticles, including magnetic, fluorescent and plasmonic nanoparticles. Such nanoconstructs may exhibit striking optical properties such as strong optical activity in the visible range (Kuzyk, 2012). To this end, plasmonic particles were assembled in solution to form helices of controlled handedness. We achieved spatial control over particle placement better than 2 nm and attachment yields of 97% and above. As a collective optical response emerging from our dispersed nanostructures, we detected pronounced circular dichroism (CD) originating from the plasmon-plasmon interactions in the particle helices. In recent experiments, we were able to show that the optical response of chiral biomolecules can be transferred from the UV into the visible region in plasmonic hotspots. Thus, sensitive detection of chiral bio-molecules may become feasible in the near future. We also found that the orientation of the helices in respect to the incoming light beam critically influences the resulting CD spectra. Our results can be explained with theoretical models based on plasmonic dipole interaction and demonstrate the potential of DNA origami for the assembly of metafluids with designed optical properties.
This research has been supported by the Volkswagen Foundation and the Deutsche Forschungs-gemeinschaft (DFG).
Seeman, N. C. Nanomaterials based on DNA. Annu. Rev. Biochem. 79, p12.1, 2010.
Kuzyk, A. et al. DNA-based self-assembly of chiral plasmonic nanostructures with tailored optical response. Nature 483, p311, 2012
*Department of Physics and Center for Nanoscience