Nguyen Ha Anh, Jupin Isabelle, Decorse Philippe, Lau-Truong Stephanie, Ammar Souad, Ha-Duong Nguyet-Thanh
ITODYS, CNRS, UMR 7086, Université de Paris 15 Rue J-A de Baïf F-75013 Paris France
Laboratory of Molecular Virology, Institut Jacques Monod, CNRS, Université de Paris France.
RSC Adv. 2019 Oct 10;9(55):32296-32307. doi: 10.1039/c9ra08015e. eCollection 2019 Oct 7.
A common challenge in nanotechnology is the conception of materials with well-defined nanoscale structure. In recent years, virus capsids have been used as templates to create a network to organize 3D nano-objects, building thus new functional nanomaterials and then devices. In this work, we synthetized 3D gold nanoclusters and we used them as Surface Enhanced Raman Scattering (SERS) sensor substrates in solution. In practice, gold nanoparticles (AuNPs) were grafted on turnip yellow mosaic virus (TYMV) capsid, an icosahedral plant virus. Two strategies were considered to covalently bind AuNPs of different sizes (5, 10 and 20 nm) to TYMV. After purification by agarose electrophoresis and digestion by agarase, the resulting nano-bio-hybrid AuNP-TYVM was characterized by different tools. Typically, dynamic light scattering (DLS) confirmed the grafting through the hydrodynamic size increase by comparing AuNPs alone to AuNP-TYMV (up to 33, 50 and 68 nm for 5, 10 and 20 nm sized AuNPs, respectively) or capsids alone (28 nm). Transmission electronic microscopy (TEM) observations revealed that AuNPs were arranged with 5-fold symmetry, in agreement with their grafting around icosahedral capsids. Moreover, UV-vis absorption spectroscopy showed a red-shift of the plasmon absorption band on the grafted AuNP spectrum (530 nm) compared to that of the non-grafted one (520 nm). Finally, by recording in solution the Raman spectra of a dissolved probe molecule, namely 1,2-bis(4-pyridyl)ethane (BPE), in the presence of AuNP-TYVM and bare AuNPs or capsids, a net enhancement of the Raman signal was observed when BPE is adsorbed on AuNP-TYVM. The analytical enhancement factor (AEF) value of AuNP-TYMV is 5 times higher than that of AuNPs. These results revealed that AuNPs organized around virus capsid are able to serve as in-solution SERS-substrates, which is very interesting for the conception of ultrasensitive sensors in biological media.
纳米技术中的一个常见挑战是构思具有明确纳米级结构的材料。近年来，病毒衣壳已被用作模板来创建一个网络，以组织三维纳米物体，从而构建新的功能纳米材料，进而制造器件。在这项工作中，我们合成了三维金纳米簇，并将其用作溶液中的表面增强拉曼散射（SERS）传感器基底。实际上，金纳米颗粒（AuNPs）被接枝到芜菁黄花叶病毒（TYMV）衣壳上，这是一种二十面体植物病毒。我们考虑了两种策略，将不同尺寸（5、10和20纳米）的AuNPs共价结合到TYMV上。通过琼脂糖电泳纯化并经琼脂酶消化后，所得的纳米生物杂化AuNP-TYVM用不同工具进行了表征。通常，动态光散射（DLS）通过比较单独的AuNPs与AuNP-TYVM（5、10和20纳米尺寸的AuNPs的流体动力学尺寸分别增加到33、50和68纳米）或单独的衣壳（28纳米），证实了接枝的发生。透射电子显微镜（TEM）观察表明，AuNPs以五重对称排列，这与其在二十面体衣壳周围的接枝情况一致。此外，紫外可见吸收光谱显示，与未接枝的AuNP光谱（520纳米）相比，接枝后的AuNP光谱上的等离子体吸收带发生了红移（530纳米）。最后，通过在溶液中记录溶解的探针分子1,2-双（4-吡啶基）乙烷（BPE）在AuNP-TYVM以及裸露的AuNPs或衣壳存在下的拉曼光谱，当BPE吸附在AuNP-TYVM上时，观察到拉曼信号有净增强。AuNP-TYVM的分析增强因子（AEF）值比AuNPs高5倍。这些结果表明，围绕病毒衣壳组织的AuNPs能够用作溶液中的SERS基底，这对于在生物介质中构思超灵敏传感器非常有意义。
