Shape effect on the antibacterial activity of silver nanoparticles synthesized via a microwave-assisted method.
Silver nanoparticles (AgNPs) are used as sustained-release bactericidal agents for water treatment. Among the physicochemical characteristics of AgNPs, shape is an important parameter relevant to the antibacterial activity. Three typically shaped AgNPs, nanocubes, nanospheres, and nanowires, were prepared via a microwave-assisted method and characterized by TEM, UV-vis, and XRD. The antibacterial activity of AgNPs was determined by OD growth curves tests, MIC tests, and cell viability assay against Escherichia coli. The interaction between AgNPs and bacterial cells was observed by TEM. The results showed that the three differently shaped AgNPs were nanoscale, 55 ± 10 nm in edge length for nanocubes, 60 ± 15 nm in diameter for nanospheres, 60 ± 10 nm in diameter and 2-4 μm in length for nanowires. At the bacterial concentration of 10(4) CFU/mL, the MIC of nanocubes, nanospheres, and nanowires were 37.5, 75, and 100 μg/mL, respectively. Due to the worst contact with bacteria, silver nanowires exhibited the weakest antibacterial activity compared with silver nanocubes and silver nanospheres. Besides, silver nanocubes mainly covered by {100} facets showed stronger antibacterial activity than silver nanospheres covered by {111} facets. It suggests that the shape effect on the antibacterial activity of AgNPs is attributed to the specific surface areas and facets reactivity; AgNPs with larger effective contact areas and higher reactive facets exhibit stronger antibacterial activity.
Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration area, School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China. scuthxs@outlook.com.|School of Civil Engineering and Transportation, South China University of Technology, Guangzhou, 510640, China. scuthxs@outlook.com.
Xuesen
X
Hong
Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration area, School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China. wen.jun.jie@foxmail.com.|School of Civil Engineering and Transportation, South China University of Technology, Guangzhou, 510640, China. wen.jun.jie@foxmail.com.
Junjie
J
Wen
Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration area, School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China. 452455914@qq.com.|School of Civil Engineering and Transportation, South China University of Technology, Guangzhou, 510640, China. 452455914@qq.com.
Xuhua
X
Xiong
Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration area, School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China. ppyyhu@scut.edu.cn.|State Key Lab of Pulp and Paper Engineering, School of Light Industry and Food Science, South China University of Technology, Guangzhou, 510640, China. ppyyhu@scut.edu.cn.
Yongyou
Y
Hu
D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects; D053768:Metal Nanoparticles / Q000737:chemistry; D008826:Microbial Sensitivity Tests; D008872:Microwaves; D008968:Molecular Conformation; D012834:Silver / Q000737:chemistry / Q000494:pharmacology*
D000900:Anti-Bacterial Agents; D012834:Silver
Antibacterial activity; Shape; Silver nanoparticles; Surface facet