In this project, a DNA origami structure is used as a platform to place metal nanoparticles and organic fluorophores (donor/acceptor pair) at predetermined positions on the DNA origami.
This platform is subsequently used to investigate how the singlet energy transfer rate (i.e., FRET) is influenced by the presence of gold nanoparticles. For many biochemical applications, the maximum distance attainable for FRET between molecules is about 80 Å. There is however a need to extend this distance and to investigate the FRET process for more complex systems involving DNA nanotechnology (using DNA origami) and FRET-Plasmonic coupling (using Donor-acceptor pair and metallic nanoparticles, respectively).
Different combinations of nanoparticle/fluorophore patterns could be made in a controlled way (see Figure). In addition, the transferring excitation and the resonance energy of the nanoparticle could be varied by varying other parameters such as the size and type of the nanoparticle, the selected donor-acceptor pair, or orientation/distance factors.
Currently, we are working on the design and synthesis of DNA origami, as well as technology development to place the selected donor/acceptor FRET pair (i.e., Alexa Fluor 568/Atto 647N) and metal nanoparticles (spherical gold nanoparticle - AuNP, 5 nm diameter) at predetermined sites on the DNA origami platform.Figure.
Schematic representation of the assembly of donor-acceptor (denoted D and A, respectively) FRET pair together with AuNPs. (a) FRET pair attached to the modified DNA strands of the origami. AuNPs functionalized with thiolated DNA single strands assembled on both sides of the origami through DNA hybridization. (b) Binding position of FRET pair and AuNPs on the DNA origami scaffold.