Figure 4

Electron energy loss spectra (a), energy (b,d), amplitude (c,e) energy-filtered (f,g,h) maps. (a) Electron energy loss spectra of a cluster of gold nanoparticles linked through DNA strands to a silicon nitride membrane for the trajectories indicated on the HAADF image of the inset. For the first trajectory (curve i), two resonance peaks can be seen at 1.6 and 2.3 eV; for the trajectory (curve ii), there is a strong LSPR at 1.9 eV. To better illustrate the two resonant modes on the trajectory (curve i), two energy maps (b,d) are presented with the centers of the fitted Gaussian to the LSPR peaks. The amplitude of the fitted Gaussian can be seen in the amplitude maps (c,e). The energy-filtered maps centered at 1.55, 1.85, and 2.35 eV are presented in (f,g,h).