Determination of Cu²⁺ ions release rate from antimicrobial copper bearing stainless steel by joint analysis using ICP-OES and XPS

Antibacterial Cu bearing stainless steels (CuSS) have been developed recently and their performance has attracted significant attention widely in biomedical, healthcare and environmental facilities in cross-disciplines. The antibacterial ability and its efficiency of the CuSS are associated to the rate and concentration of Cu2z ions releases from its surface. The surface properties such as corrosion resistance are also influenced by the amount and the rate of Cu ions released. Thus, the aim of this study focused on the determination of trace release amount of Cu2+ ions from a typical copper bearing 304 stainless steel (304CuSS). Meanwhile, the release of other key elements in the material such as Cr, Fe, Ni were also examined, and found these multiple elemental releases produced a highly synergistic effect on killing bacterium. The release rate of the metals from 304CuSS was conducted by an inductively coupled plasma optical emission spectrometry (ICP-OES). In this study, the commercial 304 stainless steel (304SS) was served as a control material, while the ICP results showed that the Cu2z ions released from 304CuSS were maintained a constant level with a release rate as low as 0?8 ppb/day/cm2. This phenomenon could be explained by a coordinating role or synergistic effects of Cu, Fe, Cr, and Ni ions. XPS surface composition analysis showed a releases contribution results in day 1 and day 14 that the reduction trend of Cu quantities in through of the surface depth of 304CuSS is consistent and comprehensible.