Corrosion Behavior and Bacterial Viability on Different Surface States of Copper

Abstract

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 Cu 0 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 Cu 2+ 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 Cu 2+ 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.

Time-Transient Effects of Silver and Copper in the Porous Titanium Dioxide Layer on Antibacterial Properties

“…Previous studies revealed a substantial difference in antibacterial effects between CuO and Cu 2 O. CuO inhibited the development of an antibacterial effect compared to metallic Cu. In contrast, thermally generated Cu 2 O was as effective as metallic Cu [50,51]. In other words, the presence of Cu 2 O and the slight amount of Cu in the TiO 2 layer are necessary to develop the antibacterial effect.…”

Visible-Light-Enhanced Antibacterial Activity of Silver and Copper Co-Doped Titania Formed on Titanium via Chemical and Thermal Treatments

“…Cu 2p 3/2 peaks were observed at around 933.0 eV for AG-CU, whereas no Cu 2p 3/2 peak was observed for AG. The Cu 2p 3/2 peak around 933.0 eV and the α’ value around 1850.4 eV suggest that Cu mainly existed as Cu 2 O on the surface of AG-CU [ 37 ]. These results indicate that copper was successfully doped into the sample surface by the present surface treatments.…”

“…Here, we briefly discuss the changes in the oxidation state of copper after antibacterial activity testing. Although XPS spectra of AG-CU after antibacterial testing should be measured to clarify the change in oxidation state of copper in the future, it is possible that Cu 2+ is formed from Cu 2 O on the surface of AG-CU after antibacterial testing because the proportion of Cu 2+ on the surface of copper metal increases after soaking in a bacteria-containing solution, and Cu 2+ is the most stable chemical state against corrosion and bacteria [ 37 ].…”

Electrochemical Deposition of Copper on Bioactive Porous Titanium Dioxide Layer: Antibacterial and Pro-Osteogenic Activities

“…The chemical state of Cu on Cu@pTiO 2 was determined using a modified Auger parameter, which was calculated according to a previously described method. 30 To calculate the integrated intensity of the peaks, background subtraction was performed using the CasaXPS software (version 2.3.24; Casa Software Ltd., Teignmouth, U.K.), following Shirley's method. 31 The sample composition was determined by CasaXPS using the following relative sensitivity factors: C 1s (1.00), O 1s (2.93), P 2p (1.192), Ca 2p (5.07), Ti 2p (7.81), and Cu 2p 3/2 (16.73).…”