Figure 3.
(a–c) The SERS spectra of 1-DDT-functionalized Au-Ag nanocages in water with 514 nm (red) and 785 nm (black) excitation, respectively. The LSPR of the nanocages was tuned to (a) 525 nm, (b) 620 nm, and (c) 790 nm. (d) The SERS spectra of 1-DDT-covered nanocages (LSPR: 525 nm) with 514 nm (red) and 785 nm (black) excitation in continuous cycles, showing the reversible nature of the trans-gauche conformational change. (e) SERS spectra of 1-DDT-covered nanocages (LSPR: 525 nm) showing other bands associated with the 1-DDT SAM with 514 nm (red) and 785 nm (black) excitation. The scale bars correspond to 14.0 adu mW−1 s−1. For all spectra, t = 120 s and Plaser = 4.5 mW for 514 nm, and 5.2 mW for 785 nm.