Thermo‐ and photosensitive gold nanoparticles (AuNPs) coated with an azobenzene‐contained P(DMA‐PAPA‐MAEL) copolymer are prepared by ligand exchange reactions. The photoisomerization of azobenzene moiety on the surface of P(DMA‐PAPA‐MAEL)‐coated AuNPs is detected by means of UV‐Vis spectroscopy with the presence or absence of free α‐cyclodextrin. When subjected to visible and UV light irradiation alternately, P(DMA‐PAPA‐MAEL)‐coated AuNPs in the presence of free α‐CD display a light‐tunable lower critical solution temperature through light‐controlled molecular recognition between the azobenzene moiety on the surface of AuNPs and free α‐CD.
