Synthesis and Antibacterial Properties of Novel ZnMn2O4–Chitosan Nanocomposites

Abstract

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 <i>w</i>/<i>v</i> 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 <i>Bacillus subtilis</i>, <i>Escherichia coli</i>, <i>Salmonella typhi</i>, and <i>Pseudomonas aeruginosa.</i> The zone of inhibition and minimum inhibitory concentration values were deduced to demonstrate the efficacy of the ZnMn₂O₄-CS nanocomposites as antibacterial agents.