Aggregation-Induced Electrochemiluminescence by Metal-Binding Protein Responsive Hydrogel Scaffolds

Functionalized hydrogels have aroused general interest due to their versatile applications in biomaterial fields. This work reports a hydrogel network composed of gold nanoclusters linked with bivalent cations such as Ca²⁺ , Mg²⁺ , and Zn²⁺ . The hydrogel exhibits both aggregation-induced emission (AIE) and aggregation-induced electrochemiluminescence (AIECL) effects. Most noteworthy, the AIECL effect (≈50-fold enhancement) is even more significant than the corresponding AIE effect (approximately fivefold enhancement). Calmodulin, a Ca²⁺ binding protein, may efficiently regulate the AIECL dynamics after specific binding of the Ca²⁺ linker, with the linear range from 0.3 to 50 µg mL^-1 and a limit of detection of 0.1 µg mL^-1 . Considering the important roles of bivalent cations in the life system, these results may pave a new avenue for the design of a biomolecule-responsive AIECL-type hydrogel with multifunctional biomedical purposes.