title: Bio-optimized energy transfer in densely packed fluorescent protein enables near-maximal luminescence and solid-state lasers.
abstract: Bioluminescent organisms are likely to have an evolutionary drive towards high radiance. As such, bio-optimized materials derived from them hold great promise for photonic applications. Here, we show that biologically produced fluorescent proteins retain their high brightness even at the maximum density in solid state through a special molecular structure that provides optimal balance between high protein concentration and low resonance energy transfer self-quenching. Dried films of green fluorescent protein show low fluorescence quenching (-7 dB) and support strong optical amplification (gnet=22 cm(-1); 96 dB cm(-1)). Using these properties, we demonstrate vertical cavity surface emitting micro-lasers with low threshold (<100 pJ, outperforming organic semiconductor lasers) and self-assembled all-protein ring lasers. Moreover, solid-state blends of different proteins support efficient Förster resonance energy transfer, with sensitivity to intermolecular distance thus allowing all-optical sensing. The design of fluorescent proteins may be exploited for bio-inspired solid-state luminescent molecules or nanoparticles.
authors.affiliation: 1] Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 65 Landsdowne Street UP-5, Cambridge, Massachusetts 02139, USA [2] SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, Fife KY16 9SS, UK.
authors.forename: Malte C
authors.initials: MC
authors.lastname: Gather
authors.affiliation: 1] Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 65 Landsdowne Street UP-5, Cambridge, Massachusetts 02139, USA [2] Harvard-MIT Health Sciences and Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Seok Hyun
authors.initials: SH
authors.lastname: Yun
mesh_terms: D004396:Coloring Agents; D004735:Energy Transfer; D005453:Fluorescence; D031541:Fluorescence Resonance Energy Transfer; D049452:Green Fluorescent Proteins / Q000737:chemistry; D007834:Lasers; D053844:Lasers, Solid-State; D049449:Luminescence; D008164:Luminescent Proteins / Q000737:chemistry*; D008422:Materials Testing; D015394:Molecular Structure; D053758:Nanoparticles / Q000737:chemistry; D055095:Optics and Photonics; D017785:Photons
chemical_list: D004396:Coloring Agents; D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins