TY - JOUR
T1 - Radiation Brightening from Virus-like Particles
AU - Tsvetkova, Irina B.
AU - Anil Sushma, Arathi
AU - Wang, Joseph Che Yen
AU - Schaich, William L.
AU - Dragnea, Bogdan
N1 - Funding Information:
The work was supported by the Army Research Office, under Award W911NF-17-1-0329, the National Science Foundation, under Awards CBET 1803440 and 1808027, and the IU Nanocharacterization Facility.
Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/10/22
Y1 - 2019/10/22
N2 - Concentration quenching is a well-known challenge in many fluorescence imaging applications. Here, we show that the optical emission from hundreds of chromophores confined onto the surface of a 28 nm diameter virus particle can be recovered under pulsed irradiation. We have found that as one increases the number of chromophores tightly bound to the virus surface, fluorescence quenching ensues at first, but when the number of chromophores per particle is nearing the maximum number of surface sites allowable, a sudden brightening of the emitted light and a shortening of the excited-state lifetime are observed. This radiation brightening occurs only under short pulse excitation; steady-state excitation is characterized by conventional concentration quenching for any number of chromophores per particle. The observed suppression of fluorescence quenching is consistent with efficient, collective relaxation at room temperature. Interestingly, radiation brightening disappears when the emitters' spatial and/or dynamic heterogeneity is increased, suggesting that the template structural properties may play a role that could be instrumental in developing virus-enabled imaging vectors that have optical properties qualitatively different than those of state-of-the-art biophotonic agents.
AB - Concentration quenching is a well-known challenge in many fluorescence imaging applications. Here, we show that the optical emission from hundreds of chromophores confined onto the surface of a 28 nm diameter virus particle can be recovered under pulsed irradiation. We have found that as one increases the number of chromophores tightly bound to the virus surface, fluorescence quenching ensues at first, but when the number of chromophores per particle is nearing the maximum number of surface sites allowable, a sudden brightening of the emitted light and a shortening of the excited-state lifetime are observed. This radiation brightening occurs only under short pulse excitation; steady-state excitation is characterized by conventional concentration quenching for any number of chromophores per particle. The observed suppression of fluorescence quenching is consistent with efficient, collective relaxation at room temperature. Interestingly, radiation brightening disappears when the emitters' spatial and/or dynamic heterogeneity is increased, suggesting that the template structural properties may play a role that could be instrumental in developing virus-enabled imaging vectors that have optical properties qualitatively different than those of state-of-the-art biophotonic agents.
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U2 - 10.1021/acsnano.9b04786
DO - 10.1021/acsnano.9b04786
M3 - Article
C2 - 31335115
AN - SCOPUS:85070542830
SN - 1936-0851
VL - 13
SP - 11401
EP - 11408
JO - ACS nano
JF - ACS nano
IS - 10
ER -