Triplet-State-Mediated Super-Resolution Imaging of Fluorophore-Labeled Gold Nanorods
Triplet-State-Mediated Super-Resolution Imaging of Fluorophore-Labeled Gold Nanorods
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DOI：
10.1002/cphc.201300767
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发表时间：
2014-03-17
期刊：
影响因子：
2.9
通讯作者：
Willets, Katherine A.
中科院分区：
文献类型：
--
作者：
Blythe, Karole L.;Titus, Eric J.;Willets, Katherine A.
三重态介导的超分辨率成像用于绘制与金纳米棒表面结合的荧光标记双链 DNA 的位置。为了分离与纳米棒表面结合的单个荧光团，优化了成像条件，使得大多数荧光团被迫进入三重暗状态，并且一次检测到来自大约一个分子的荧光。然后将发射的单分子的荧光拟合到二维 (2D) 高斯分布，以定位其相对于纳米棒基底的位置。重建的超分辨率图像显示出与纳米棒的形状和方向非常一致，尽管基于相关原子力显微镜，它们始终低估了纳米棒的尺寸。金纳米棒表面上的表观 DNA 配体结合表现出显着的异质性，例如优先结合纳米棒末端、均匀结合纳米棒表面以及位点特异性结合纳米棒的单端。这种异质性将隐藏在典型的系综或衍射限制测量中，突出了对单纳米粒子超分辨率成像研究的需要。
Triplet-state-mediated super-resolution imaging was used to map the positions of fluorescently labeled double-stranded DNA bound to the surface of gold nanorods. In order to isolate individual fluorophores bound to the nanorod surface, imaging conditions were optimized such that the majority of the fluorophores were forced into a triplet dark state, and fluorescence from approximately one molecule at a time was detected. The fluorescence from the emitting single molecule was then fit to a two-dimensional (2D) Gaussian to localize its position relative to the nanorod substrate. The reconstructed super-resolution images showed excellent agreement with the shape and orientation of the nanorods, although, based on correlated atomic force microscopy, they consistently under-estimated nanorod size. The apparent DNA ligand binding on the gold nanorod surface showed significant heterogeneity, with examples of preferential binding to nanorod ends, uniform binding across the nanorod surface, and site-specific binding to a single end of the nanorod. This heterogeneity would be hidden in a typical ensemble or diffraction-limited measurement, highlighting the need for single nanoparticle super-resolution imaging studies.