Single-molecule surface-enhanced Raman spectroscopy from a molecularly-bridged silver nanoparticle dimer

TEM image of a Ag nanoparticle dimer linked by a single 4,4′-diaminoazobenzene molecule. SERS spectrum of the linker obtained from this dimer shows temporal fluctuations. This blinking is interpreted in terms of single molecule dynamics of the linker periodically brought into the hot spot in the interstice between the two nanoparticles.