Determining molecular orientation via single molecule SERS in a plasmonic nano-gap

作者：Marshall Addison R L; Stokes Jamie; Viscomi Francesco N; Proctor John E; Gierschner Johannes; Bouillard Jean Sebastien G^*; Adawi Ali M^*

来源：Nanoscale, 2017, 9(44): 17415-17421.

DOI：10.1039/c7nr05107g

In this work, plasmonic nano-gaps consisting of a silver nanoparticle coupled to an extended silver film have been fully optimized for single molecule Surface-Enhanced Raman Scattering (SERS) spectroscopy. The SERS signal was found to be strongly dependent on the particle size and the molecule orientation with respect to the field inside the nano-gap. Using Finite Difference Time Domain (FDTD) simulations to complement the experimental measurements, the complex interplay between the excitation enhancement and the emission enhancement of the system as a function of particle size were highlighted. Additionally, in conjunction with Density Functional Theory (DFT), the well-defined field direction in the nano-gap enables to recover the orientation of individual molecules.

• 出版日期2017-11-28