UV and pH-responsive supra-amphiphiles driven by combined interactions for controlled self-assembly behaviors

In order to fabricate a novel supra-amphiphile with multiple stimulus properties, we developed the strategy of introducing a bi-functional linker to bridge the hydrophilic and hydrophobic building blocks together, by utilizing more than one kind of interaction. We characterized the assembled structure and morphology of the supra-amphiphile using transmission electron microscopy (TEM), dynamic light scattering (DLS) and X-ray diffraction (XRD). ¹H NMR and UV-vis spectroscopy studies revealed that the amphiphile was constructed by the effect of host-guest recognition and a dynamic covalent bond, which could be switched ''on'' and ''off'' via UV irradiation and pH variation stimuli, respectively. This responsiveness realized finely controllable self-assembly behaviors of the supra-amphiphile, which was thus able to encapsulate and release the drug model rhodamine B.