Chen Yen-Chi, Yu Kuo-Pin
Institute of Environmental and Occupational Health Sciences, National Yang-Ming University, No.155, Sec.2, Li-Nong Street, Taipei, 11221 Taiwan, ROC.
Institute of Environmental and Occupational Health Sciences, National Yang-Ming University, No.155, Sec.2, Li-Nong Street, Taipei, 11221 Taiwan, ROC.
Colloids Surf B Biointerfaces. 2017 Jun 1;154:195-202. doi: 10.1016/j.colsurfb.2017.03.031. Epub 2017 Mar 18.
The antimicrobial efficacy of silver nanoparticles (AgNPs) is influenced by many factors, including the particle size, AgNP oxidation state and support materials. In this study, AgNPs are synthesized and supported by two types of TiO powders (P25 and Merck TiO) using two heat-treatment temperatures (120 and 200°C). The formation of well-dispersed AgNPs with diameters ranging from 3.2 to 5.7nm was confirmed using transmission electron microscopy. X-ray photoelectron spectroscopy and X-ray diffraction indicated that the majority of the AgNPs were reduced from Ag to Ag at 200°C. The AgNP antimicrobial activity was determined by the zone of inhibition against three fungi, A. niger, P. spinulosum and S. chartarum, and two bacteria, E. coli (Gram-negative) and S. epidermidis (Gram-positive). The antimicrobial activity of metallic AgNPs was more pronounced than that of silver nitrate and some antimicrobial drugs. The AgNPs exhibited optimal antimicrobial efficacy when the AgNP dispersion on the surface of TiO was in the region between 0.2 and 0.7μg-Ag/m. The minimum (critical) AgNP concentrations needed to inhibit the growth of bacteria (E. coli) and fungi (A. niger) were 13.48 and 25.4μg/mL, respectively. The results indicate that AgNPs/TiO nanocomposites are a promising disinfectant against both bacteria and fungi.
银纳米颗粒（AgNPs）的抗菌效果受多种因素影响，包括粒径、AgNP氧化态和载体材料。在本研究中，使用两种热处理温度（120和200°C），由两种类型的TiO粉末（P25和默克TiO）合成并负载AgNPs。使用透射电子显微镜确认形成了直径范围为3.2至5.7nm的分散良好的AgNPs。X射线光电子能谱和X射线衍射表明，在200°C时，大多数AgNPs从Ag+还原为Ag0。通过对三种真菌（黑曲霉、小刺青霉和炭疽菌）以及两种细菌（大肠杆菌（革兰氏阴性）和表皮葡萄球菌（革兰氏阳性））的抑菌圈来测定AgNP的抗菌活性。金属AgNPs的抗菌活性比硝酸银和一些抗菌药物更为显著。当TiO表面的AgNP分散度在0.2至0.7μg-Ag/m²之间时，AgNPs表现出最佳抗菌效果。抑制细菌（大肠杆菌）和真菌（黑曲霉）生长所需的最低（临界）AgNP浓度分别为13.48和25.4μg/mL。结果表明，AgNPs/TiO纳米复合材料是一种有前景的针对细菌和真菌的消毒剂。
