Can we control the position and orientation of optically-active molecules?

How small fluorescent molecules absorb and transfer light energy between each other or with other optical species such as semiconductor quantum dots or gold nanoparticles is important to realize high sensitivity in sensing, high-resolution cellular imaging, energy harvesting, data storage, and electronics. For example, miniaturizing light harvesting, much like Nature performs photosynthesis, demands careful arrangement of chromophores in an organic three-dimensional lattice which requires not only calibrated spatial distances of the chromophores, but controlled relative orientation as well. While it is still challenging for scientists to make predictable protein-based scaffolds or templates to host chromophores, nucleic acid self-assembly and chemical amenability has made it possible to make DNA-dye structures that are excellent platforms to probe how spatial and orientational organization of these dyes can tune or tailor their optoelectronic energy transfer capabilities. In our group, we build such dye-DNA constructs and interrogate their optoelectronic properties in collaboration with spectroscopists and computational chemists.