Chinese Researchers Develop Anti COVID19 Stainless Steel

Severe acute respiratory syndrome coronavirus 2 exhibits strong stability on conventional stainless steel surface, with infectious virus detected even after two days, posing a high risk of virus transmission via surface touching in public areas. In order to mitigate the surface toughing transmission, Chinese researchers have developd the first SS with excellent anti-pathogen properties against SARS-COV-2. The stabilities of SARS-CoV-2, H1N1 influenza A virus and Escherichia coli on the surfaces of Cu-contained SS, pure Cu, Ag-contained SS, and pure Ag were investigated. It is discovered that pure Ag and Ag-contained SS surfaces do not display apparent inhibitory effects on SARS-CoV-2 and H1N1. In comparison, both pure Cu and Cu-contained SS with a high Cu content exhibit significant antiviral properties. Significantly, the developed anti-pathogen SS with 20 wt.% Cu can distinctly reduce 99.75% and 99.99% of viable SARS-CoV-2 on its surface within 3 and 6 hours, respectively. In addition, the present anti-pathogen SS also exhibits an excellent inactivation ability for H1N1 influenza A virus and Escherichia coli. Interestingly, the Cu ion concentration released from the anti-pathogen SS with 10 wt% and 20 wt% Cu was notably higher than the Ag ion concentration released from Ag and the Ag-contained SS. Lift buttons made of the present anti-pathogen SS are produced using mature powder metallurgy technique, demonstrating its potential applications in public areas and fighting the transmission of SARS-CoV-2 and other pathogens via surface touching.The transmission of pathogenic bacteria and viruses in public areas has been a long-standing issue for public health. Infectious diseases induced by these bacteria or viruses are not only afflicting millions of people annually but also causing an immeasurable economic cost. In particular, the current coronavirus disease 2019 is causing a global pandemic. As the two most popular inorganic antimicrobial elements, Ag and Cu have attracted significant research interests because of their low toxicity to animal cells and well-known ability to inactivate a broad spectrum of bacteria and viruses. Studies have reported that Ag nanoparticles, some Ag-contained composites, copper, brass, and Cu-contained high-entropy alloy have antimicrobial properties. In particular, it has been reported that pure Cu exhibits an excellent antiviral efficiency towards SARS-CoV-2 and H1N1 influenza A virus. However, replacing SS products with pure Cu in public areas is impractical due to its high cost, low strength, and less corrosion-resistant capability. Some studies have introduced antimicrobial properties into conventional SS by surface coating or ion implantation. Nevertheless, it is necessary to note that the thickness of coatings is limited (e.g., physical vapor deposition, cold-spray, and ion implantation, thickness < 1 mm). The damage of coatings on the surface can significantly affect the antimicrobial properties of SS, resulting in a limited service duration. Therefore, low-cost SS with long-term antimicrobial properties is required for replacing conventional SS products used in public areas.