Collaborative Research: Room-temperature Superfluorescence in Multi-fluorophore Protein Cages and Its Origins

Indiana University, Bloomington IN

Investigators

Abstract

Ordinary light from an incandescent lamp is emitted by the independent excitation and relaxation of atoms in the filament. Twice the number of emitters makes the light twice as bright. Atoms are no ordinary emitters and can synchronize when certain conditions are met. When synchronization happens, the ensemble becomes super-radiant, and doubling the number of emitters quadruples light intensity. Synchronizing quantum emitters is easier said than done, but can be achieved under certain conditions. In this project, hundreds of molecular dyes will be chemically bound to the protein shell of a small plant virus. After a fast excitation pulse, the dyes spontaneously synchronize and collectively emit a burst of intense light. This project will tease out the mechanism by which the virus scaffold promotes coupling and synchronization of the dyes, at room temperature. Project outcomes could lead to future technologies for high contrast bioimaging. The research project will be complemented by STEM outreach activities, including opportunities for students to explore the innovation to invention pipeline. The spatial scale and the symmetry afforded by a virus scaffold have not been sufficiently explored in relation to emergent behavior, mainly due to the lack of comparable structural control. The preservation of quantum coherence at room temperature is especially intriguing. Emission occurs after pulsed excitation, as a delayed intense burst of ∼ 10 ps duration. Such non-classical dynamics contrast those of the much slower conventional exponential decay of uncorrelated chromophores. As a consequence, optical power density at deep sub-wavelength spatial scale, maximum turnover rate, and signal-to-background ratio dramatically increase. The project’s goal will be pursued through a theory-experiment collaboration. Approaches will couple experimental spectroscopic and molecular biology manipulations with predictive all-atom simulations that examine the structure and emergent dynamics of engineered virus-like particles. Proof-of-principle experiments are envisioned that exploit super-radiance and illustrate improved microscopic imaging contrast in single-particle analysis applications. The outcomes of this project could inspire future biophotonic technologies, providing control and understanding of the relationship between molecular structure and dynamics, and improved photonic properties. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.