Corrosion Behavior and Bacterial Viability on Different Surface States of Copper

Abstract

This study investigates the interaction between Escherichia coli（E. coli） and various surface states of Cu. Pure Cu was first immersed in ultrapure water for 24 h at 298 K and then oxidized at 673 and 1273 K. Subsequently, its surface chemical states were characterized using X-ray photoelectron spectroscopy （XPS）. The oxidized specimens were immersed in both bacteria-free and bacteria-containing solutions, and the release of Cu ions from each specimen was evaluated. The specimens that existed mainly as Cu^＋ on the surface were found to promote the elution of Cu ions because of the presence of E. coli in the immersion solution. In contrast, the specimen that existed mainly as Cu^2＋ showed no changes in Cu release in the presence of bacteria. XPS analyses conducted before and after immersion in bacteria-free and bacteria-containing solutions showed that the presence of E. coli inhibited the generation of Cu^2＋ on the surface and promoted Cu ion elution. This study proposes that the specific corrosion behavior of Cu in response to bacteria is beneficial for developing its antibacterial properties.