Synthesis, characterization, and comparison of antibacterial effects and elucidating the mechanism of ZnO, CuO and CuZnO nanoparticles supported on mesoporous silica SBA-3

Abstract

Silanized iminodiacetic acid (GLYMO-IDA) modified mesoporous silica (G-SBA) was prepared following a co-condensation method. G-SBA/Cu²⁺, G-SBA/Zn²⁺ and G-SBA/Cu²⁺-Zn²⁺ were obtained through the impregnation method with coordination by GLYMO-IDA. SBA/CuO, SBA/ZnO, and SBA/CuZnO were generated after calcination of G-SBA/Cu²⁺, G-SBA/Zn²⁺ and G-SBA/Cu²⁺-Zn²⁺. After modification, the amount of metal ion was 6 to 70 times higher than that of the blank mesoporous silica. The diameter of nano-copper oxide particles in mesoporous silica was 4.8 nm. The bacteriostatic rates of SBA/CuO at a copper oxide concentration of 250 ppm against <i>E. coli</i> and <i>S. aureus</i> were 85.87% and 100%, respectively. SBA/CuO and SBA/CuZnO with {111} lattice planes exhibited better antibacterial effects compared to the commercial-grade nano-zinc oxide and nano-copper oxide. When exposed to ultraviolet light, SBA/CuZnO displayed the highest photocatalytic activity and optimal antimicrobial effect. Therefore, SBA/CuZnO can be an alternative to antibiotics because of its non-toxic nature and good antibacterial properties.