Copper ion composite hydrogels for enhanced antibacterial performance

With the increasing prevalence of antibiotic resistance (AMR), the development of new antimicrobial agents has garnered significant attention. This study synthesized to prepare sodium alginate–polyacrylamide antibacterial hydrogels crosslinked with different concentrations of Cu 2+ to systematically investigate their physicochemical properties and antibacterial performance. Through chemical crosslinking to incorporate copper ions into the hydrogel network, we characterized the composite hydrogels using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The experimental results indicated that copper ion concentration critically modulates the crosslinking degree and structural properties of hydrogels. Notably, elemental mapping analysis (figure 5) revealed optimal copper ion homogeneity in TG-Cu2 hydrogels with 0.2544 g basic copper sulfate, correlating with their superior antibacterial performance of 4.78, 4.98, and 6.31 log CFU/ml reductions at 4, 8, and 12 h respectively. This nonlinear concentration-efficacy relationship suggests in the early stage of antibacterial activity balanced ion distribution and sustained release kinetics are crucial for antibacterial efficacy. Our findings provide fundamental insights into structure–property relationships of copper-incorporated hydrogels, advancing their application in antimicrobial materials development.