文摘
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 鈥渉ot鈥?electrons. Astonishingly, the shell-isolated Ag nanoparticles (Ag SHINs), as 鈥渟mart plasmonic dusts鈥? reveal a 鈭?000-fold ensemble enhancement of rhodamine isothiocyanate (RITC) on a quartz substrate in surface-enhanced fluorescence. The presented 鈥渟mart鈥?Ag nanostructures offer a unique way for the promotion of ultrahigh sensitivity and reliability in plasmon-enhanced spectroscopies.