Open AccessUltrafast Collective Excited-State Dynamics of a Virus-Supported Fluorophore Antenna
Author(s) -
Joseph Holmes,
Arathi Anil Sushma,
Irina B. Tsvetkova,
W. L. Schaich,
Richard D. Schaller,
Bogdan Dragnea
Publication year - 2022
Publication title -
the journal of physical chemistry letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.563
H-Index - 203
ISSN - 1948-7185
DOI - 10.1021/acs.jpclett.2c00262
Subject(s) - chromophore , excited state , relaxation (psychology) , fluorophore , chemical physics , ultrashort pulse , ultrafast laser spectroscopy , molecular physics , fluorescence , physics , materials science , chemistry , atomic physics , optics , photochemistry , laser , biology , neuroscience
Radiation brightening was recently observed in a multifluorophore-conjugated brome mosaic virus (BMV) particle at room temperature under pulsed excitation. On the basis of its nonlinear dependence on the number of chromophores, the origins of the phenomenon were attributed to a collective relaxation. However, the mechanism remains unknown. We present ultrafast transient absorption and fluorescence spectroscopic studies which shed new light on the collective nature of the relaxation dynamics in such radiation-brightened, multifluorophore particles. Our findings indicate that the emission dynamics is consistent with a superradiance mechanism. The ratio between the rates of competing radiative and nonradiative relaxation pathways depends on the number of chromophores per virus. The findings suggest that small icosahedral virus shells provide a unique biological scaffold for developing nonclassical, deep subwavelength light sources and may open new avenues for the development of photonic probes for medical imaging applications.