Influence of morphology and surface properties on the antibacterial action of GaOOH microparticles

The growing threat of antibiotic-resistant bacteria necessitates the development of alternative antimicrobial agents. Gallium oxyhydroxide (GaOOH) is a promising candidate, though its direct antibacterial efficacy is unexplored. This study provides the first direct evidence of GaOOH microparticles exhibiting cytotoxic effects against both Gram-positive Staphylococcus aureus (S.aureus) and Gram-negative Escherichia coli (E. coli). Orthorhombic GaOOH particles were synthesized hydrothermally, with their morphology influenced by the pH of the synthesis process, as confirmed by scanning electron microscopy and x-ray diffraction analysis. Antibacterial assays revealed that cytotoxicity against E. coli increases with a higher synthesis pH, a trend we demonstrate to be associated with the enhanced defect density in particles, as supported by photoluminescence spectra and FTIR analysis. The study underscores the significant influence of synthesis conditions on the morphology and crystallinity of the resulting GaOOH microparticles, highlighting the influence of surface characteristics on antibacterial agents.