Influence of particle size on the antibacterial activity of zinc oxide

The influence of particle size on the antibacterial activity of ZnO powders was investigated using powders with different particle sizes ranging from 0.1 to 0.8 mum. By measuring the change in electrical conductivity with bacterial growth, it was found that the antibacterial activity of ZnO increased with decreasing particle size and increasing powder concentration. The changes of antibacterial action for Staphylococcus aureus were similar to those for Escherichia coli, However, the influence of particle size for Staphylococcus aureus was less than that for Escherichia coli. (C) 2001 Elsevier Science Ltd. All rights reserved.