Multifunctional Hydrogels with Antibacterial, Fluorescent, and Conductive Properties via Acylhydrazone–Zn 2+ Coordination and Hydrophobic Association

Developing multifunctional hydrogels that simultaneously integrate antibacterial activity, fluorescence responsiveness, and electrical conductivity remains a significant challenge in soft materials design. Herein, we report a multifunctional hydrogel platform based on synergistic hydrophobic association and acylhydrazone–Zn 2+ coordination. A hydrophobic monomer (BHPAA) is incorporated into the hydrogel network via a solvent‐exchange strategy, forming hydrophobic domains that, together with subsequent Zn 2+ coordination, yield a tensile strength of 1.07 MPa and toughness of 3.38 MJ/m 3 . The acylhydrazone–Zn 2+ complexation triggers strong fluorescence enhancement (> 1400%) with high selectivity toward Zn 2+ , enabling rewritable information encryption using Zn 2+ as ink and EDTA as eraser. Meanwhile, the hydrogel exhibits good electrical conductivity (6.32 mS·cm −1 ) and potent antibacterial activity (48% against E. coli , 93% against S. aureus ). The combination of these three functionalities—antibacterial, fluorescent, and conductive—within a single material platform makes the hydrogel a promising candidate for applications in flexible electronics, information security, and biomedical devices. This work offers a versatile strategy for designing multifunctional hydrogels via metal‐coordination chemistry toward advanced functional materials.