Preparation of ZnO-supported 13X zeolite particles and their antimicrobial mechanism
- PDF / 521,974 Bytes
- 9 Pages / 584.957 x 782.986 pts Page_size
- 25 Downloads / 264 Views
n Wu, Zishou Zhang, and Kancheng Maia) Materials Science Institute, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, People’s Republic of China; Key Laboratory of Polymeric Composites and Functional Materials of Ministry of Education, Guangzhou 510275, People’s Republic of China; and Guangdong Provincial Key Laboratory of High Performance Resinbased Composites, Guangzhou 510275, People’s Republic of China (Received 12 June 2017; accepted 2 October 2017)
To improve the antimicrobial properties of ZnO, ZnO-supported 13X zeolite (X-ZnO) was prepared via the facile chemical method. Antimicrobial activities of X-ZnO and ZnO were tested against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria. X-ZnO showed noticeable antimicrobial activities against E. coli and S. aureus under visible light conditions, especially against E. coli. The minimum inhibitory concentration (MIC) of X-ZnO against E. coli was 0.12–0.24 mg/mL. However, there were still much bacteria alive in the nano-ZnO suspensions at the same concentration. To elucidate the antimicrobial activities of X-ZnO, the average concentration of the total reactive oxygen species (ROS) and Zn21 ions released from X-ZnO and nano-ZnO were quantitatively analyzed. The obtained results indicated that the average concentration of ROS produced by supported ZnO was much higher than that of nano-ZnO. And the released Zn21 ions from X-ZnO and nano-ZnO suspensions were much lower than the MIC of Zn21. Thus, it is believed that the production of ROS in X-ZnO and nano-ZnO suspensions resulted in the difference of antibacterial activities. I. INTRODUCTION
Antimicrobial agents can be broadly classified into two types, organic compounds and inorganic materials. Organic antimicrobial agents have broad source, and quick and efficient antimicrobial properties, but their applications are limited due to their sensitivity to high temperature and pressures.1 Inorganic antimicrobial agents attract much attention due to their safe, nontoxic, and stable properties.2,3 Inorganic antimicrobial agents mainly include metal particles and metal-oxide particles, such as copper, silver, TiO2, ZnO, and so on.4,5 Many reports revealed that ZnO showed antimicrobial activities against Gram-positive and Gram-negative bacteria.6–13 Moreover, it is found that the antimicrobial activities of ZnO were strongly influenced by its size and morphology.11,14–19 Ohira et al.11 observed that the antimicrobial activities of ZnO can be improved with diminution of particle size. This was explained due to an increase in the surface area/volume ratio, which resulted in increased generation of H2O2. Zhang et al.14 and Contributing Editor: Lakshmi Nair a) Address all correspondence to this author. e-mail: [email protected] DOI: 10.1557/jmr.2017.410
Jones et al.15 also proved improved antimicrobial activities of ZnO against Escherichia coli and Staphylococcus aureus with diminution of particle size. To obtain small-particle-size and special-shape ZnO particles, porous materia
Data Loading...
