Optimizing FRET Efficiency in Multi-Donor DNA-Organized Nanostructures

S. Buckhout-White, W.R. Algar, C. Spillman, J. Mellinger, E.R. Goldman, M.G. Ancona, I.L. Medintz
Naval Research Laboratory, US

Keywords: DNA, FRET, self-assembly

Summary:

A key step in the ultimate realization of synthetic light harvesting is the understanding of the efficient multi-step fluorescence resonance energy transfer (FRET) that is present in naturally occurring photo synthetic systems. In an effort to understand the rules by which these systems follow, we have utilized DNA as a nanoscale scaffold for the assembly of organic chromophores. Using the specificity inherent to Watson-Crick binding, structural DNA allows for the formation of intricate networks with exquisite binding selectivity. Combined with established ligation chemistries, we can form an array of self-assembled DNA architectures to create prescriptively spaced dyes with resolution equal to the spacing between nucleotides. These nanostructures range from simple linear wires to complex 3-dimensional structures all while using the same principles and components for assembly. We have begun to explore multi donor - single acceptor systems, examining parameters such as dye-to-dye spacing and donor, acceptor ratios, and the affect these have on the terminal acceptor photo luminescence (PL).