Controllable “Clicked-to-Assembled” Plasmonic Core–Satellite Nanostructures and Its Surface-Enhanced Fluorescence in Living Cells

摘要： The assembly of noble-metal core?satellite (CS) nanostructures is an appealing means to control their plasmonic properties for applications such as surface-enhanced ?uorescence or Raman scattering. However, till now there is a lack of some rapid or convenient methods to construct stable CS nanostructures. Here, we proposed a “clicked-to-assembly” strategy based on the fast and speci?c “click chemistry” reaction between trans-cyclooctene (TCO) and 1,2,4,5-tetrazine (Tz). The CS nanostructures were constructed within 8 min by simple mixing of TCO- or Tz-modi?ed nanoparticles (TCO-NPs or Tz-NPs) without any catalysts or heating required. Transmission electron microscopy experiments show that the constructed CS nanostructures are uniform, and particularly the number of “satellite” nanoparticles in the core surface is controllable by simply adjusting the feeding ratio of TCO-NPs or Tz-NPs in the reaction. The strong surface plasmon coupling e?ect (SPCE) was observed in these CS nanostructures, which was dependent on the coverage degree, size and composition of the satellite, and core NPs. The nanostructures with tuned surface plasmon resonance (SPR) e?ect were tried for the surface-enhanced ?uorescence in living cells. Such well-de?ned CS nanostructures could potentially serve as e?cient SPR-enhanced ?uorescent probes as diagnostics or biomedical imaging agents in nanomedicine.