Pushing the Photon Limit: Nanoantennas Increase Maximal Photon Stream and Total Photon Number.
Pushing the Photon Limit: Nanoantennas Increase Maximal Photon Stream and Total Photon Number.
复制标题
DOI：
10.1021/acs.jpclett.6b00491
复制
发表时间：
2016-05-05
期刊：
影响因子：
--
通讯作者：
van Hulst NF
中科院分区：
文献类型：
--
作者：
Wientjes E;Renger J;Cogdell R;van Hulst NF
纳米天线因其在激发和发射方面的荧光增强作用而广为人知。已经报告了3-4个数量级的增强。然而在实践中，由于分子处于单重态，特别是三重态激发态的时间，光子发射受到饱和的限制。最大光子流限制了可实现的增强。此外，光漂白还限制了发射的光子总数。有限的亮度和观察时间是应用的一个缺点，特别是在生物学中。在这里，我们挑战这一光子限制，表明纳米天线实际上可以增加饱和强度和光稳定性。到目前为止，纳米天线的这种改变极限的作用几乎没有被探索过。具体地说，我们证明了在饱和激发条件下，单个捕光络合物在光漂白之前显示出超过50倍的天线增强的光子发射流，总光子数增加10倍，最高可检测到108个光子。这项工作从另一个侧面展示了纳米天线在单分子生物学领域的巨大潜力。
Nanoantennas are well-known for their effective role in fluorescence enhancement, both in excitation and emission. Enhancements of 3–4 orders of magnitude have been reported. Yet in practice, the photon emission is limited by saturation due to the time that a molecule spends in singlet and especially triplet excited states. The maximal photon stream restricts the attainable enhancement. Furthermore, the total number of photons emitted is limited by photobleaching. The limited brightness and observation time are a drawback for applications, especially in biology. Here we challenge this photon limit, showing that nanoantennas can actually increase both saturation intensity and photostability. So far, this limit-shifting role of nanoantennas has hardly been explored. Specifically, we demonstrate that single light-harvesting complexes, under saturating excitation conditions, show over a 50-fold antenna-enhanced photon emission stream, with 10-fold more total photons, up to 108 detected photons, before photobleaching. This work shows yet another facet of the great potential of nanoantennas in the world of single-molecule biology.