Corrosion behavior and bacterial viability on different surface states of copper

This study investigates the interaction between E. coli bacteria and various surface states of Cu. Pure Cu was oxidized at 298 K, 673 K, and 1273 K, and its surface chemical state was characterized using X-ray photoelectron spectroscopy. The oxidized specimens were immersed in both bacteria-free and bacteria-containing solutions, and the release of Cu ions from each specimen was evaluated. As a result, the specimens, which existed as mainly Cu⁰ or Cu⁺ on the surface, exhibited the same corrosion behavior and promoted the elution of Cu ions due to the presence of E. coli in the immersion solution. In contrast, the release of Cu ions from the specimen that existed mainly as Cu²⁺ did not change in the presence of bacteria. According to the XPS analyses before and after immersion in bacteria-free and bacteria-containing solutions, the generation of Cu²⁺ on the surface was inhibited by the presence of E. coli, and promoted Cu ion elution. This study proposes that the specific corrosion behavior of Cu due to bacteria is beneficial for developing its antibacterial properties.