Ultrafast Excitation Transfer in Cy5 DNA Photonic Wires Displays Dye Conjugation and Excitation Energy Dependency
Ultrafast Excitation Transfer in Cy5 DNA Photonic Wires Displays Dye Conjugation and Excitation Energy Dependency
复制标题
DOI：
10.1021/acs.jpclett.0c01020
复制
发表时间：
2020-05-21
影响因子：
5.7
通讯作者：
Medintz, Igor L.
中科院分区：
文献类型：
--
作者：
Mazuski, Richard J.;Diaz, Sebastian A.;Medintz, Igor L.
DNA支架使荧光分子的碱基对特异性定位成为可能，从而在控制多染料相互作用方面实现纳米级精度。基于DNA的分子光子线（MPW）扩展了这一概念，允许在纳米尺度上进行光捕获和光子能量的定向传播。最常见的MPW实例利用福斯特共振能量转移（FRET），并且最近显示相同染料种类之间的FRET（HomoFRET）增加MPW可以起作用的距离和效率。虽然相邻荧光团之间增加的接近度可用于增加能量转移效率，但随着染料分子之间的距离变得与它们的尺寸相当（类似于2nm），FRET假设被打破。在这里，我们比较了染料共轭与单与二聚体Cy5染料重复作为HomoFRET MPW组件上的双交叉DNA支架。在室温（RT）和低光条件下，末端标记的未偶联染料分子提供了最佳的转移，而Cy5二聚体显示出超快（
DNA scaffolds enable base-pair-specific positioning of fluorescent molecules, allowing for nanometer-scale precision in controlling multidye interactions. Expanding on this concept, DNA-based molecular photonic wires (MPWs) allow for light harvesting and directional propagation of photonic energy on the nanometer scale. The most common MPW examples exploit Forster resonance energy transfer (FRET), and FRET between the same dye species (HomoFRET) was recently shown to increase the distance and efficiency at which MPWs can function. Although increased proximity between adjacent fluorophores can be used to increase the energy transfer efficiency, FRET assumptions break down as the distance between the dye molecules becomes comparable to their size (similar to 2 nm). Here we compare dye conjugation with single versus dimer Cy5 dye repeats as HomoFRET MPW components on a double-crossover DNA scaffold. At room temperature (RT) under low-light conditions, end-labeled uncoupled dye molecules provide optimal transfer, while the Cy5 dimers show ultrafast (