Development of a Supramolecular Cobalt(II) Metallohydrogel from L-Serine-Based Low Molecular Weight Gelator for Dual Antimicrobial and Semiconducting Applications

Abstract

A Co(II)-metallohydrogel was synthesized by combining cobalt(II) nitrate and L-serine in the presence of potassium hydroxide in an aqueous medium at room temperature. The resulting hydrogel demonstrated excellent mechanical strength, as confirmed through rheological studies. Field emission scanning electron microscopy (FESEM) and energy-dispersive X-ray (EDX) mapping revealed a hierarchical microstructure and confirmed the presence of essential elements such as Co, C, N, O, and K. FT-IR spectroscopy shed light on the supramolecular interactions involved in gel formation, while powder X-ray diffraction (PXRD) provided information on the material’s crystalline features. Optical absorption analysis confirmed the semiconducting nature of the gel, showing notably high electron mobility compared to similar materials. Furthermore, the metallohydrogel exhibited strong antibacterial activity against both Gram-positive (B. subtilis, S. aureus) and Gram-negative (E. coli, P. aeruginosa) pathogens. These multifunctional properties underscore the material’s potential for future applications in both flexible electronics and biomedical technology.