Efficient antimicrobial properties of layered double hydroxide assembled with transition metals via a facile preparation method

Mg2+ in MgAl-layered double hydroxides nanoparticles was substituted with different divalent transition metal ions (MAl-LDHs, M: Mg2+, Cu2+, Ni2+, Co2+, and Mn2+) via a facile method to be used as antibacterial agents. The phase structural and morphological characterizations of MAl-LDHs were investigated by XRD, FTIR spectroscopy and TEM. The results have shown that all of MAl-LDHs had typical layered structures except MnAl-LDH which contained Mn3O4 phases. Particular morphology of MnAl-LDH with ellipsoids, spherical and rod-like structure and CuAl-LDH with rod-like shape existed. IC50 (the concentrations providing 50% antibacterial activity) values of CuAl-LDH, NiAl-LDH, CoAl-LDH, and MnAlLDH in broth dilution tests were similar to 800-1500 mg/mL. Dosages of CuAl-LDH, CoAl-LDH, and MnAl-LDH with >10 mm inhibition zone in disk diffusion tests were similar to 150-300 mu g/disk. Antibacterial mechanism of MAl-LDHs may be attributed to the synergistic factors including effected surroundings, surface interactions, morphology of particles, ROS and metal ions. The results indicate a facile method to synthesis LDHs based effective antibacterial agents with the potential application in the area of water treatment and antibacterial coating. (c) 2019 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.