Su Yu, Wen Shengping, Luo Xiaojun, Xue Feihu, Wu Shaojun, Yuan Baozhen, Lu Xuanzhao, Cai Chenxin, Jiang Li-Ping, Wu Ping, Zhu Jun-Jie
State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu 210023, China.
Jiangsu Key Laboratory of New Power Batteries, College of Chemistry & Materials Science, Nanjing Normal University, Nanjing, Jiangsu 210097, China.
ACS Appl Mater Interfaces. 2021 Jan 13;13(1):135-147. doi: 10.1021/acsami.0c16683. Epub 2020 Dec 24.
Plasmonically engineered nanomaterials based on Au-Ag for surface-enhanced Raman scattering (SERS)-based biomedicine is of great importance but is still far behind clinical needs because of the poor compatibility between sensitivity and safety. Here, robust plasmonically encoded Raman scattering nanoparticles, named Au core-Raman-active molecule-Ag shell-Au shell nanoparticles (CMSS NPs), were synthesized. The as-developed CMSS NPs possess a unique exterior ultrathin Au shell (∼2.2 nm thickness) that plays double key roles as an effective wrapping layer as well as a plasmonic enhancing layer, thereby showing not only extraordinary stability against oxidative damages and bioerosion but also outstanding SERS sensitivity because of the stronger in-built electromagnetic field, achieving a significant SERS enhancement factor of 3.3 × 10. The results confirm that the individual CMSS NPs show ultrahigh brightness, reproducibility, selectivity, and biocompatibility in single-cell Raman imaging. Moreover, ultrabright tumor imaging with 1 × 1 mm area can be quickly achieved within 35 s under open-air condition. Furthermore, by secondary plasmonic encoding, the CMSS NPs flexibly serve as nanobeacon to monitor single-cell autophagy with improved accuracy. The CMSS NPs are expected as versatile SERS probes that enable ultrabright, fast, and precise Raman-based bioimaging and clinical bioapplications.
基于金 - 银的等离激元工程纳米材料用于基于表面增强拉曼散射（SERS）的生物医学具有重要意义，但由于灵敏度和安全性之间的兼容性较差，仍远远落后于临床需求。在此，合成了一种坚固的等离激元编码拉曼散射纳米颗粒，称为金核 - 拉曼活性分子 - 银壳 - 金壳纳米颗粒（CMSS NPs）。所开发的CMSS NPs具有独特的外部超薄金壳（厚度约为2.2 nm），它起着双重关键作用，既是有效的包裹层又是等离激元增强层，从而不仅对氧化损伤和生物侵蚀具有非凡的稳定性，而且由于更强的内置电磁场而具有出色的SERS灵敏度，实现了3.3×10的显著SERS增强因子。结果证实，单个CMSS NPs在单细胞拉曼成像中显示出超高的亮度、重现性、选择性和生物相容性。此外，在露天条件下，35 s内即可快速实现1×1 mm面积的超亮肿瘤成像。此外，通过二次等离激元编码，CMSS NPs可灵活用作纳米信标，以更高的精度监测单细胞自噬。CMSS NPs有望成为通用的SERS探针，实现基于拉曼的超亮、快速和精确生物成像及临床生物应用。
