Diseases caused by pathogenic microbes affect humans, animals, and plants, reduced agricultural productivity and health crises. Numerous studies have recently explored potential solutions to address these challenges. In this study, we propose a simple cost-effective approach involving carbon quantum dots (CQDs)-based metal complexes, which demonstrate enhanced bactericidal activity against pathogenic bacteria. The incorporation of CQDs with metals such as silver (Ag), copper (Cu), zinc (Zn), iron (Fe), nickel (Ni), and manganese (Mn) significantly enhances the antibacterial activity of the metals through mechanisms such as oxidative stress generation, membrane rupture, and interference with bacterial metabolic activities. CQDs were synthesized using hydrothermal methods from green sources, and their metal complexes were prepared via a covalent coordination reaction. The properties of the synthesized CQDs and their metal complexes were analyzed using FTIR, SEM, EDX, to confirm their successful formation. The antimicrobial efficacy of these compounds was evaluated against two pathogenic bacteria, including Gram-positive strains (Staphylococcus aureus) and Gram-negative strains (Escherichia coli). The integration of metal centers into the CQDs backbone markedly enhanced bactericidal effectiveness across all tested cases. Notably, CQDs-metal complexes exhibited the highest bactericidal effects, attributed to the intrinsic activity of metal ions. These findings underscore the critical role of the coordinated bond between metal centers and CQDs ligands in determining the antibacterial efficacy of these complexes. The remarkable bactericidal activity demonstrated by these metal complexes highlights their potential for diverse applications, including resisting agricultural diseases, developing soft and tough tissue adhesives for biomedical use, and enhancing safety in the food industry.
