Biomedical Engineering Reference
In-Depth Information
Figure 4.7
SEM images of monodispersed SiO
2
particles.
4.7 Silver Nanoparticles
Silver has been used as an antibacterial agent since ancient times. Romans
stored wine in silver urns to prevent spoilage. Chinese emperors ate with
silver chopsticks for better health whereas Americans used to put silver
coins in milk and water to avoid spoilage in old times. Indian tradition
of using silver utensils and feeding babies with silver spoon is due to the
same reason. Till date silver is being used as antibacterial agent and many
commercial products are introduced which exploit antibacterial prop-
erty of silver. Silver inhibits the growths of bacteria by deactivating the
bacteria's oxygen metabolism enzyme. In turn this destroys bacteria's cell
membranes, stopping the replication of bacteria's DNA. Recent research
shows that antibacterial properties of silver are retained or even enhanced
in nano form similar to its bulk form. Although the literature describes a
broad range of superb and innovative methods for obtaining nanosilver,
only a few of them are concerned with the main stream production.
Laser
ablation
Different
method of
preparation
of Ag NPs
Photo
reduction
Chemical
reduction
Microwave
irradiation
