Figure 2From: Facile purification of colloidal NIR-responsive gold nanorods using ions assisted self-assembly Absorption spectra of aqueous solutions. (a) As-made gold NR mixture, (b) purified gold NRs (red curve), and (c) nanoparticles kept in supernatant after purification. The photograph (inset) shows the corresponding colour of NR mixture solution, purified NRs solution and supernatant from left to rightBack to article page