Crystallography facet-dependent antibacterial activity: The case of Cu ₂O

The dependence of antibacterial activities on different crystallography facets has been demonstrated by taking Cu₂O crystals as an example. Owing to the different atomic arrangement of the exposed surfaces, Cu ₂O octahedral crystals bounded by {111} facets exhibited higher activity in killing E. coli than cubic ones bounded by {100} facets. Zeta potential measurement demonstrated that the electrostatic interaction between E. coli and octahedral crystals was more profitable in inactivating bacteria than that between E. coli and cubic ones. Moreover, the suspending medium, where the bactericidal process takes place, has been found to play a crucial role on the bactericidal efficiency. This work presents a way for the sterilization or killing of bacteria efficiently and selectively.