Fig. 3.
Reversible optical properties of photoresponsive NPs. (A) UV–vis spectra of PMAMC-capped Au NPs CH2Cl2 solution (c = 8.3 μM) when irradiated with 365-nm UV light. (B) UV–vis spectra of PMAMC-capped Au NPs CH2Cl2 solution upon irradiation with subsequent 254-nm UV light after being exposed to 365-nm UV light for 180 min in A. (A and B, Insets) The maximum peak position λmax and the absorbance of the SPR peaks at λmax as a function of UV irradiation time. (C) Reversible photocontrol of the SPR peak position of PMAMC-capped Au NPs during the self-assembly (green bars) and disassembly (white bars) cycles upon the irradiation with 365- and 254-nm UV light, respectively.