Silver is arguably the best plasmonic material in terms of optical performance. However, wide application of Ag and Ag-containing nanoparticles is usually hindered by two major drawbacks, namely, chemical degradation and cytotoxicity. We report herein a synthetic method for highly monodisperse polymer-coated Ag nanorods, which are thereby protected against external stimuli (oxidation, light, heat) and are noncytotoxic to various cell lines. The monodispersity of Ag nanorods endows them with narrow plasmon bands, which are tunable into the near-infrared biological transparency window, thus facilitating application in bioanalytical and therapeutic techniques. We demonstrate intracellular surface-enhanced Raman scattering (SERS) imaging using Ag nanorods encoded with five different Raman reporter molecules. Encoded Ag nanorods display long-term stability in terms of size, shape, optical response, and SERS signal. Our results help eliminate concerns of instability and cytotoxicity in the application of Ag-containing nanoparticles with enhanced optical response, toward the development of bioapplications.

中文翻译：

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用于生物应用的屏蔽银纳米棒。

就光学性能而言，银可以说是最好的等离子体材料。然而，Ag和含Ag的纳米颗粒的广泛应用通常受到两个主要缺点的阻碍，即化学降解和细胞毒性。我们在此报告了一种用于高度单分散的聚合物包覆的Ag纳米棒的合成方法，从而可以免受外界刺激（氧化，光，热），并且对各种细胞系无细胞毒性。Ag纳米棒的单分散性使其具有窄的等离激元能带，该等离激元能带可调谐到近红外生物透明窗中，从而有利于在生物分析和治疗技术中的应用。我们展示了使用五个不同的拉曼报道分子编码的Ag​​纳米棒的细胞内表面增强拉曼散射（SERS）成像。编码的Ag​​纳米棒在尺寸，形状，光学响应和SERS信号方面显示出长期稳定性。我们的研究结果有助于消除对含银纳米颗粒的应用在光学应用中的不稳定性和细胞毒性的担忧，从而提高了生物应用的发展。