The high-efficiency synergistic and broad-spectrum antibacterial effect of cobalt doped zinc oxide quantum dots (Co-ZnO QDs) loaded cetyltributylphosphonium bromide (CTPB) modified MMT (C-MMT) nanocomposites

Abstract Co-ZnO QDs/C-MMT nanocomposites is prepared via a facile chemical precipitation method with cetyltributylphosphonium bromide (CTPB) modified MMT (C-MMT) as the carrier. TEM and SEM results show that Co-ZnO QDs could be absorbed on the surface of C-MMT, even embedded into the layered structures of C-MMT. Antibacterial performances showed the inhibition rate of 1 mL 3.0 mg mL−1 Co-ZnO QDs/C-MMT composites to Gram-negative bacteria Escherichia coli, Gram-positive bacteria Staphylococcus aureus and fungi Aspergillus flavus could reach to 97.9 %, 95.6 % and 88.0 %, respectively. EPR results, TEM analysis and adsorption experiment indicated that Co-ZnO QDs/C-MMT nanocomposites, combining the high ROS production of Co-ZnO QDs and excellent bacteria-adsorbed capability of C-MMT and Co-ZnO QDs, thus display specific-targeting capability, high-efficiency antibacterial activity, suggesting the potential application as a novel antibacterial agent.