Synthesis and Characterization of Sodium Alginate/Graphene Oxide Hydrogel Crosslinked by Cu 2+ for Curcumin Delivery

ABSTRACT A multifunctional sodium alginate/graphene oxide/copper ion (SA/GO/Cu 2+ ) hydrogel was developed as a controlled curcumin delivery system with enhanced physicochemical stability and antibacterial activity. The hydrogel network was formed via ionic coordination between alginate carboxylate groups and Cu 2+ ions, combined with hydrogen bonding and interfacial interactions involving graphene oxide. Key formulation parameters were systematically optimized, and the optimal hydrogel (4 wt% SA, 0.03 M Cu 2+ , 0.6 mg mL −1 GO, 90 min gelation) exhibited a balanced combination of high swelling capacity, improved water retention, and enhanced mechanical strength. Structural and physicochemical characterization (XRD, FTIR, SEM–EDS mapping, and DSC) confirmed the homogeneous incorporation of GO and Cu 2+ and the formation of a reinforced, predominantly amorphous network with improved thermal stability. The optimized hydrogel exhibited high curcumin loading efficiency at an initial curcumin concentration of 150 ppm and sustained, concentration‐dependent release behavior, which followed an anomalous (non‐Fickian) diffusion mechanism. Moreover, the curcumin‐loaded SA/GO/Cu 2+ hydrogel showed pronounced antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa . These results highlight the potential of the SA/GO/Cu 2+ hydrogel as a multifunctional platform for controlled drug delivery and antibacterial wound dressing applications.