Split-GFP: SERS Enhancers in Plasmonic Nanocluster Probes
Split-GFP: SERS Enhancers in Plasmonic Nanocluster Probes
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DOI：
10.1002/smll.201601631
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发表时间：
2016-11-09
期刊：
影响因子：
13.3
通讯作者：
Pinaud, Fabien
中科院分区：
文献类型：
--
作者：
Chung, Taerin;Koker, Tugba;Pinaud, Fabien
等离子体金属纳米粒子组装成热点表面增强拉曼散射（SERS）纳米簇探针是一种强大但具有挑战性的超灵敏生物传感方法。基于自互补肽和蛋白质的脚手架策略对这些组装越来越感兴趣，但这种混合纳米团簇的电子和光子特性仍然难以预测和优化。本研究以分裂绿色荧光蛋白（sGFP）片段作为分子胶，以GFP发色团作为拉曼报告子，组装各种金纳米粒子（AuNP）簇，并通过数值模拟探索其等离子体性质。结果表明，在AuNP/GFP杂化纳米簇中，等离子体纳米间隙的GFP播种增加了AuNP之间的近场偶极耦合，并提供了超过108的SERS增强因子。在所研究的不同纳米簇中，AuNP/GFP链允许近红外SERS检测GFP发色团咪唑啉酮/外环C=C振动模式，理论增强因子为10(8)-10(9)。对于较大的AuNP/GFP组件，在紧密排列的纳米颗粒之间存在非GFP种子纳米间隙会降低拉曼活性热点的近场增强，这表明过度的聚类会降低SERS扩增。该研究为利用拉曼报告子作为等离子体纳米粒子之间的分子胶，优化用于远程生物传感的热点SERS纳米探针的受控组装提供了理论依据。
The assembly of plasmonic metal nanoparticles into hot spot surface-enhanced Raman scattering (SERS) nanocluster probes is a powerful, yet challenging approach for ultrasensitive biosensing. Scaffolding strategies based on self-complementary peptides and proteins are of increasing interest for these assemblies, but the electronic and the photonic properties of such hybrid nanoclusters remain difficult to predict and optimize. Here, split-green fluorescence protein (sGFP) fragments are used as molecular glue and the GFP chromophore is used as a Raman reporter to assemble a variety of gold nanoparticle (AuNP) clusters and explore their plasmonic properties by numerical modeling. It is shown that GFP seeding of plasmonic nanogaps in AuNP/GFP hybrid nanoclusters increases near-field dipolar couplings between AuNPs and provides SERS enhancement factors above 108. Among the different nanoclusters studied, AuNP/GFP chains allow near-infrared SERS detection of the GFP chromophore imidazolinone/exocyclic C=C vibrational mode with theoretical enhancement factors of 10(8)-10(9). For larger AuNP/GFP assemblies, the presence of non-GFP seeded nanogaps between tightly packed nanoparticles reduces near-field enhancements at Raman active hot spots, indicating that excessive clustering can decrease SERS amplifications. This study provides rationales to optimize the controlled assembly of hot spot SERS nanoprobes for remote biosensing using Raman reporters that act as molecular glue between plasmonic nanoparticles.