Fig. 2

A UV–vis absorption spectra (Inset: photographs of the AuNR@Ag colloid solutions with different Ag nanoshell thickness), B HR-TEM images and C EDX line-scanning profiles along the line in inset C of AuNR@Ag with different Ag nanoshell thicknesses obtained by changing the amounts of 0.01 M AgNO₃ to a 350 μL, b 250 μL, c 150 μL, respectively