Radiation Brightening from Virus-like Particles
Radiation Brightening from Virus-like Particles
复制标题
病毒样颗粒的辐射增亮
DOI：
10.1021/acsnano.9b04786
复制
发表时间：
2019
期刊：
影响因子：
17.1
通讯作者：
Dragnea, Bogdan
中科院分区：
文献类型：
--
作者：
Tsvetkova, Irina B.;Anil Sushma, Arathi;Wang, Joseph Che-Yen;Schaich, William L.;Dragnea, Bogdan
浓度猝灭是许多荧光成像应用中众所周知的挑战。在这里，我们表明，从数百个生色团限制在一个28 nm直径的病毒颗粒的表面上的光发射可以恢复脉冲照射下。我们发现，随着紧密结合在病毒表面的发色团数量的增加，荧光猝灭首先增强，但是当每个颗粒的发色团数量接近允许的最大表面位点数量时，观察到发射光的突然变亮和激发态寿命的缩短。这种辐射增亮仅发生在短脉冲激发下;稳态激发的特征在于每个颗粒的任何数量的发色团的常规浓度猝灭。所观察到的荧光猝灭的抑制与室温下的有效集体弛豫一致。有趣的是，当发射体的空间和/或动态异质性增加时，辐射增亮消失，这表明模板结构特性可能在开发具有与最先进的生物光子剂的光学特性定性不同的光学特性的病毒使能成像载体中起作用。
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.