“Smart” Ag Nanostructures for Plasmon-Enhanced Spectroscopies

• Published in: Journal of the American Chemical Society Vol. 137; no. 43; pp. 13784 - 13787
• Main Authors: Li, Chao-Yu, Meng, Meng, Huang, Sheng-Chao, Li, Lei, Huang, Shao-Rong, Chen, Shu, Meng, Ling-Yan, Panneerselvam, Rajapandiyan, Zhang, San-Jun, Ren, Bin, Yang, Zhi-Lin, Li, Jian-Feng, Tian, Zhong-Qun
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 04.11.2015
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/jacs.5b09682

Silver is an ideal candidate for surface plasmon resonance (SPR)-based applications because of its great optical cross-section in the visible region. However, the uses of Ag in plasmon-enhanced spectroscopies have been limited due to their interference via direct contact with analytes, the poor chemical stability, and the Ag+ release phenomenon. Herein, we report a facile chemical method to prepare shell-isolated Ag nanoparticle/tip. The as-prepared nanostructures exhibit an excellent chemical stability and plasmonic property in plasmon-enhanced spectroscopies for more than one year. It also features an alternative plasmon-mediated photocatalysis pathway by smartly blocking “hot” electrons. Astonishingly, the shell-isolated Ag nanoparticles (Ag SHINs), as “smart plasmonic dusts”, reveal a ∼1000-fold ensemble enhancement of rhodamine isothiocyanate (RITC) on a quartz substrate in surface-enhanced fluorescence. The presented “smart” Ag nanostructures offer a unique way for the promotion of ultrahigh sensitivity and reliability in plasmon-enhanced spectroscopies.