Gold nanorod/nanosphere clustering by split-GFP fragment assembly for tunable near-infrared SERS detections
Gold nanorod/nanosphere clustering by split-GFP fragment assembly for tunable near-infrared SERS detections
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DOI：
10.1364/ome.7.003270
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发表时间：
2017-09
影响因子：
2.8
通讯作者：
Taerin Chung;T. Koker;F. Pinaud
中科院分区：
文献类型：
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作者：
Taerin Chung;T. Koker;F. Pinaud
我们描述了由金纳米棒（AuNR）和金纳米球（AuNS）胶体组成的等离子体纳米团簇的近场特性，这些胶体是使用自互补分裂绿色荧光蛋白（sGFP）片段组装的。这些混合AuNR/AuNS异质团簇的光学响应和场增强特性的数值模拟进行（i）作为AuNS结合位置的函数，沿着边缘或在AuNR的尖端，（ii）作为每个AuNR的AuNS的大小和数量的函数，以及（iii）作为相对于光的主要偏振态的团簇几何形状和取向的函数。我们表明，近红外（NIR）活性等离子体热点，提供大的Sers增强因子的振动指纹从重建的GFP发色团一致获得纵向极化激发的AuNR/AuNS纳米组件。提出了一组具有足够灵活的几何形状和良好的光谱共振与传统的近红外激光激发在785 nm的簇的近红外Sers检测的GFP发色团的增强因子在107-108倍的范围内。本研究为利用绿色荧光蛋白作为拉曼报告分子改进热点AuNR/AuNS Sers纳米探针的组装提供了基础。
We describe the near-field properties of plasmonic nanoclusters made of gold nanorod (AuNR) and gold nanosphere (AuNS) colloids that are assembled using self-complementary split-green fluorescence protein (sGFP) fragments. Numerical modeling of the optical responses and field enhancement characteristics for these hybrid AuNR/AuNS heteroclusters were performed (i) as a function of AuNS binding locations along the edges or at the tips of AuNRs, (ii) as a function of the size and number of AuNS per AuNR, and (iii) as a function of cluster geometry and orientation with respect to the major polarization states of light. We show that near-infrared (NIR)-active plasmonic hot spots that provide large SERS enhancement factors of the vibrational fingerprints from the reconstructed GFP-chromophore are consistently obtained for longitudinally polarized-excitation of the AuNR/AuNS nanoassemblies. A set of clusters having sufficiently flexible geometry and good spectral resonance with traditional NIR laser excitations at 785 nm is proposed for NIR SERS detection of the GFP chromophore with enhancement factors in the range of 107-108 folds. This study provides grounds to improve the assembly of hot spot AuNR/AuNS SERS nanoprobes for NIR biosensing using GFP as a Raman reporter.