School of Chemistry and Chemical Engineering, and Institute of Molecular Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200240, China.
CAS Key Laboratory of Interfacial Physics and Technology, Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China.
Sci Adv. 2019 Sep 27;5(9):eaau4506. doi: 10.1126/sciadv.aau4506. eCollection 2019 Sep.
Tailored metal nanoclusters have been actively developed to manipulate light at the subwavelength scale for nanophotonic applications. Nevertheless, precise arrangement of molecules in a hot spot with fixed numbers and positions remains challenging. Here, we show that DNA origami metamolecules with Fano resonances (DMFR) can precisely localize single dye molecules and produce quantified surface-enhanced Raman scattering (SERS) responses. To enable tailored plasmonic permutations, we develop a general and programmable method for anchoring a set of large gold nanoparticles (L-AuNPs) on prescribed -tuple docking sites of super-origami DNA frameworks. A tetrameric nanocluster with four spatially organized 80-nm L-AuNPs exhibits peak-and-dip Fano characteristics. The drastic enhancement at the wavelength of the Fano minimum allows the collection of prominent SERS spectrum for even a single dye molecule. We expect that DMFR provides physical insights into single-molecule SERS and opens new opportunities for developing plasmonic nanodevices for ultrasensitive sensing, nanocircuits, and nanophotonic lasers.
定制金属纳米团簇被积极开发，以在亚波长尺度上操纵光，用于纳米光子学应用。然而，在具有固定数量和位置的热点中精确排列分子仍然具有挑战性。在这里，我们展示了具有 Fano 共振（DMFR）的 DNA 折纸超分子（DMFR）可以精确地定位单个染料分子并产生定量的表面增强拉曼散射（SERS）响应。为了实现定制的等离子体排列，我们开发了一种通用且可编程的方法，用于将一组大的金纳米颗粒（L-AuNP）固定在超折纸 DNA 框架的预定 -tuple 对接位点上。具有四个空间组织的 80nm L-AuNP 的四聚体纳米团簇表现出峰和谷 Fano 特征。在 Fano 最小值的波长处的剧烈增强允许甚至单个染料分子收集突出的 SERS 光谱。我们预计 DMFR 将为单分子 SERS 提供物理见解，并为开发用于超灵敏传感、纳米电路和纳米光子学激光的等离子体纳米器件开辟新的机会。
