Enhanced antibacterial behavior of a novel Cu-bearing high-entropy alloy

Abstract

Contact infection of bacteria and viruses has been a critical threat to human health. The worldwide outbreak of COVID-19 put forward urgent requirements for the research and development of the self-antibacterial materials, especially the antibacterial alloys. Based on the concept of high-entropy alloys, the present work designed and prepared a novel Co 0.4 FeCr 0.9 Cu 0.3 antibacterial high-entropy alloy with superior antibacterial properties without intricate or rigorous annealing processes, which outperform the antibacterial stainless steels. The antibacterial tests presented a 99.97% antibacterial rate against Escherichia coli and a 99.96% antibacterial rate against Staphylococcus aureus after 24 hours. In contrast, the classic antibacterial copper-bearing stainless steel only performed the 71.50% and 80.84% antibacterial rate, respectively. The results of the reactive oxygen species analysis indicated that the copper ion release and the immediate contact with copper-rich phase had a synergistic effect in enhancing antibacterial properties. Moreover, this alloy exhibited excellent corrosion resistance when compared with the classic antibacterial stainless steels, and the compression test indicated the yield strength of the alloy was 1015 MPa. These findings generate fresh insights into guiding the designs of structure-function-integrated antibacterial alloys.

Bio-high entropy alloys: Progress, challenges, and opportunities

“…Biological HEAs with antibacterial properties usually contain these antibacterial elements, and Chen et al ( Chen C. et al, 2022 ) designed CrFeNiCuSi HEA with antibacterial properties, which achieved 97.45% inhibition of E. coli . Similarly, the synergistic effect of copper ions and copper-rich phase greatly improved the antibacterial performance of Bio-HEAs, and CoFeCrCu HEA showed superior antibacterial performance with 99.97% inhibition of E. coli and 99.96% inhibition of Staphylococcus aureus after 24 h, much higher than conventional antibacterial alloy materials ( Ren et al, 2022 ).…”

“…On the other hand, in HEA, Cu and other elements (such as Fe) form a potential difference to form a miniature galvanic cell, releasing a large amount of Cu 2+ , which further exerts the bactericidal effect of Cu ions. In addition, according to Ren et al ( Ren et al, 2022 ), direct contact of bacteria with the copper-rich phase in Bio-HEAs produces an effective concentration of ROS (H 2 O 2 ) during incubation, which induces oxidative stress, resulting in an antibacterial effect.…”

“…On the other hand, in HEA, Cu and other elements (such as Fe) form a potential difference to form a miniature galvanic cell, releasing a large amount of Cu 2+ , which further exerts the bactericidal effect of Cu ions. In addition, according to Ren et al (Ren et al, 2022), direct contact of bacteria with the copper-rich phase in Bio-HEAs produces an effective concentration of ROS (H 2 O 2 ) during FIGURE 15 (A) Potentiodynamic polarization curves of arc-melted TiZrNbTaMo HEA, as well as Ti-6Al-4V, 316L, and CoCrMo alloys in PBS for comparison of biocompatibility (Wang and Xu, 2017). Ti2p peaks after etching times of 360 and 1,080 s immersed in FBS for 28 days: (B) and (C) for TiTaHfNb, (D) and (E) for TiTaHfNbZr, (F) and (G) for TiTaHfMoZr (Gurel et al, 2021).…”

Synthesis, and characterization of metallic glassy Cu–Zr–Ni powders decorated with big cube Zr2Ni nanoparticles for potential antibiofilm coating applications

“… Coated materials Coating approach Bacterial strain Percentage inhibition References Elemental Cu Ready made Acinetobacter calcoaceticus Stenotrophomonas maltophilia > 3.5 log CFU/cm 2 Gomes et al 55 Cu 90 Ni 10 Ready made Pseudomonas sp. < 10 3 CFU/ml Vanithakumari, et al 56 4 × Cu–TiO 2 Arc melting Staphylococcus epidermidis < 10 4 CFU/ml Mauerer, et al 57 Steriall ® copper alloys Cu 90 and 70% Ready made Environmental bacteria 2.0 CFU/cm 2 Colin, et al 58 Ti—5 wt% Cu Arc melting S. aureus E. coli 3.5 × 10 3 CFU/ml (24 h) Liu et al 59 Ti 76.2 Zr 3.4 Cu 29.5 Arc melting S. aureus E. coli 10 3 CFU/ml Kolawole et al 60 Co 0.4 FeCr 0.9 Cu x ( x = 0.3 and 0.5) Cu-HEAs Arc melting S. aureus E. coli < 10 3 CFU/ml Ren et al 61 Cu 50 Ti 40 Ni 10 …”

Combinatorial development of antibacterial FeCoCr-Ag medium entropy alloy

“…Recently, high-entropy alloys have attracted increasing attention due to their remarkable mechanical properties [1,2], corrosion resistance [3], processability [4,5], etc. Although many of these attributes are desired for antibacterial coating materials, the development of antibacterial high-entropy alloys has received less attention until recently [6][7][8].…”