Figure 13: SERS spectra of R6G adsorbed on samples shown in Figures 11(a) and 11(b). Both samples contained accurate concentrations of AuNRs of 106 cm−2 and R6G of 10−13 mol in the detection areas: laser wavelength of 1064 nm; laser power of 0.5 W; excitation spot size of 100 μm; integration number of 254; and spectral resolution of 2 cm−1. The samples were positioned perpendicular to the excitation source. Reproduced with permission from [31]. Copyright 2007 American Institute of Physics.