Synthesis and Antibacterial Properties of Novel ZnMn₂O₄-Chitosan Nanocomposites

The development of productive antibacterial agents from nontoxic materials via a simple methodology has been an immense research contribution in the medicinal chemistry field. Herein, a sol-gel one-pot reaction was used to synthesize hybrid composites of hausmannite-chitosan (Mn₃O₄-CS) and its innovative derivative zinc manganese oxide-chitosan (ZnMn₂O₄-CS). Fixed amounts of CS with different metal matrix w/v ratios of 0.5%, 1.0%, 1.5%, and 2.0% for Mn and Zn precursors were used to synthesize ZnMn₂O₄-CS hybrid composites. X-ray diffraction analysis indicated the formation of polycrystalline tetragonal-structured ZnMn₂O₄ with a CS matrix in the hybrids. Fourier-transform infrared spectroscopic analysis confirmed the formation of ZnMn₂O₄-CS hybrids. Detailed investigations of the surface modifications were conducted using scanning electron microscopy; micrographs at different magnifications revealed that the composites' surface changed depending on the ratio of the source materials used to synthesize the ZnMn₂O₄-CS hybrids. The antibacterial activity of the Mn₃O₄-CS and ZnMn₂O₄-CS composites was tested against various bacterial species, including Bacillus subtilis, Escherichia coli, Salmonella typhi, and Pseudomonas aeruginosa. The zone of inhibition and minimum inhibitory concentration values were deduced to demonstrate the efficacy of the ZnMn₂O₄-CS nanocomposites as antibacterial agents.