Asymmetric Naphthalene Monoimide-Based Semiconducting Zn(II)-Supramolecular Metallohydrogel: A Multifunctional Material for Antibacterial and Optoelectronic Applications

Herein, we demonstrate robust self-healing Zn(II)-induced metallohydrogel formation using an asymmetric naphthalene monoimide bearing a glycine unit (<i>^A</i>NMI-G). Detailed spectroscopic and microscopic studies revealed that directional metal ion coordination, along with orthogonal π-π stacking interactions, drives the anisotropic self-aggregation of the <i>^A</i>NMI-G/Zn²⁺ complex, leading to the formation of ill-defined short-aspect-ratio nanofibers. The nanofibers are further clustered via hierarchical self-assembly, eventually producing flower-like flaky superstructures. Interestingly, gel phase crystallization was observed. Rheological analysis proved the viscoelastic nature of the metallohydrogel. XRD and DFT studies suggested the formation of tilted lamellae of the <i>^A</i>NMI-G/Zn²⁺ complex within the hydrogel matrix. In vivo and in vitro data revealed that the metallohydrogel is biocompatible, and its antibacterial property was confirmed by inhibiting the Gram-negative bacterium <i><i>E. coli</i></i>. Finally, the xerogel showed semiconducting properties in both dark and light conditions. These findings highlight the metallohydrogel's dual potential in electronics, due to its superior charge transport phenomenon, and in biomedicine, owing to its biocompatibility and antibacterial effects.