NaCl-Responsive\nUltrashort Peptide to Trigger Self-Assembly\nof TPE-Capped Supramolecular Hydrogelator

With the advantages of less invasiveness and better shape\nadaptability,\nin situ-forming hydrogels are desired biomaterials as scaffolds, drug\ncarriers, and so on. Herein, a negatively charged NaCl-responsive\nultrashort peptide sequence (EEH) is reported whose electrostatic\nrepulsion can be reduced through the charge-shielding effect. Under\nphysiological conditions, its AIEgen-capped amphiphile TPE-GEEH of\nlow concentration (1 mg/mL) presents NaCl-triggered morphological\ntransformation from micelle to closely packed fiber with enhanced\nemission, which can be applied to biosense sodium ion (Na<sup>+</sup>) with high sensitivity and quick response. At a slightly acidic\npH, 10 mg/mL TPE-GEEH undergoes sol–gel transition upon addition\nof NaCl (100 mM) with improved mechanical properties, which should\nbe useful to develop an in situ-forming hydrogel. Overall, our report\nprovides a simple strategy to construct NaCl-responsive assemblies\nfor potential application in biosensors and drug delivery system.