A novel green amino acid derivative hydrogel with multi-stimulus responsiveness

Even though amino acid derivatives are always used as the building blocks to construct gels in supramolecular chemistry, there is still no report about N -alpha-Fmoc- L -valine (Fmoc-V) hydrogel induced by metal ions. Herein, a novel green Fmoc-V hydrogel with stimuli responsiveness was reported. A total of eight metal ions are applied to fabricate gels, but only Zn 2+ and Cu 2+ can induce Fmoc-V hydrogel formation. The formation of Fmoc-V hydrogel is verified by rheometer detection. FT-IR, UV–vis, and SAXS detections are used to study the formation mechanism of Fmoc-V hydrogel, implying hydrogen bond, metal–ligand, and π-π stacking interactions are the driving forces to gel formation. Moreover, this novel green hydrogel with high electrical conductivity performs multiple stimulus responsiveness to temperature, metal ion, and acid, illustrating its great potential applications in various areas.