纳米银离子和颗粒的抗菌活性。

Antibacterial activity of nanosilver ions and particles.

机构信息

Particle Technology Laboratory, Institute of Process Engineering, Department of Mechanical and Process Engineering, ETH Zurich, CH-8092 Zurich, Switzerland.

出版信息

Environ Sci Technol. 2010 Jul 15;44(14):5649-54. doi: 10.1021/es101072s.

DOI:10.1021/es101072s

PMID:20583805

Abstract

The antibacterial activity of nanosilver against Gram negative Escherichia coli bacteria is investigated by immobilizing nanosilver on nanostructured silica particles and closely controlling Ag content and size. These Ag/SiO(2) nanoparticles were characterized by S/TEM, EDX spectroscopy, X-ray diffraction the exposed Ag surface area was measured qualitatively by O(2) chemisorption. Furthermore, the fraction of dissolved nanosilver was determined by measuring the released (leached) Ag(+) ion concentration in aqueous suspensions of such Ag/SiO(2) particles. The antibacterial effect of Ag(+) ions was distinguished from that of nanosilver particles by monitoring the growth of E. coli populations in the presence and absence of Ag/SiO(2) particles. The antibacterial activity of nanosilver was dominated by Ag(+) ions when fine Ag nanoparticles (less than about 10 nm in average diameter) were employed that release high concentrations of Ag(+) ions. In contrast, when relatively larger Ag nanoparticles were used, the concentration of the released Ag(+) ions was lower. Then the antibacterial activity of the released Ag(+) ions and nanosilver particles was comparable.

摘要

采用将纳米银固定在纳米结构的二氧化硅颗粒上并严格控制银含量和粒径的方法，研究了纳米银对革兰氏阴性大肠杆菌的抗菌活性。通过 S/TEM、EDX 光谱、X 射线衍射对 Ag/SiO(2)纳米粒子进行了表征，通过 O(2)化学吸附定性地测量了暴露的 Ag 表面积。此外，通过测量此类 Ag/SiO(2)颗粒的水悬浮液中释放（浸出）的 Ag(+)离子浓度，确定了纳米银的溶解分数。通过监测在存在和不存在 Ag/SiO(2)颗粒的情况下大肠杆菌群体的生长，将 Ag(+)离子的抗菌作用与纳米银颗粒的抗菌作用区分开来。当使用平均粒径小于约 10nm 的细 Ag 纳米颗粒时，纳米银的抗菌活性主要由 Ag(+)离子决定，因为这些细 Ag 纳米颗粒释放出高浓度的 Ag(+)离子。相比之下，当使用相对较大的 Ag 纳米颗粒时，释放的 Ag(+)离子浓度较低。然后，释放的 Ag(+)离子和纳米银颗粒的抗菌活性相当。