Nanoparticles with pulse laser controlled antibacterial properties
When gold-coated silver nanoplates are irradiated with a pulsed laser, they change shape into a sphere and release silver ions which produces a strong antibacterial effect. Credit: Dr. Takuro Niidome
Pulsed laser irradiation on the gold-coated silver nanoparticles (Ag@Au NPs) provided a solution to the problem. When Ag@Au NPs are irradiated with a pulse laser, the morphology of the NPs changes from a triangular plate to a spherical shape. This is due to the metals melting from the heat of the laser pulse.
The researchers showed that Ag@Au NPs were about half triangular and half spherical before irradiation but jumped to 94% spherical after irradiation. Furthermore, the silver-to-gold ratio of the pre-irradiation Ag@Au NPs was around 22:1, but the post-irradiation ratio was near 4.5:1.
This was interpreted by the researchers as the generation of defects in the gold-coating which allowed for some of the silver to escape as ions. This is an important aspect of the pulsed laser irradiation process since the release of silver produces the bactericidal effect.
“We have developed a method to activate the antibacterial properties of silver nanoparticles at will,” said Professor Takuro Niidome, leader of the research group. “Our experiments have shown that, while non-irradiated gold-coated silver nanoparticles have only minor antibacterial properties, the effects are significantly increased after pulsed laser irradiation.
We hope to develop this technology further as a method of managing bacteria that have developed antibacterial resistance.”
The irradiated Ag@Au NPs were highly effective against Escherichia coli, resulting in a 0% colony survival rate. Silver NPs alone were similarly effective, but the Ag@Au NPs had the advantages of being activated as needed and did not tend to clump together like the silver NPs.
This research was posted online in the Royal Society of Chemistry journal Nanoscale on 11 October 2017.
###
[Reference]
Kyaw, K., Ichimaru, H., Kawagoe, T., Terakawa, M., Miyazawa, Y., Mizoguchi, D., Tsushida, M, Niidome, T. (2017). Effects of pulsed laser irradiation on gold-coated silver nanoplates and their antibacterial activity. Nanoscale. doi:10.1039/c7nr06513b
Media Contact
All latest news from the category: Physics and Astronomy
This area deals with the fundamental laws and building blocks of nature and how they interact, the properties and the behavior of matter, and research into space and time and their structures.
innovations-report provides in-depth reports and articles on subjects such as astrophysics, laser technologies, nuclear, quantum, particle and solid-state physics, nanotechnologies, planetary research and findings (Mars, Venus) and developments related to the Hubble Telescope.
Newest articles
Trotting robots reveal emergence of animal gait transitions
A four-legged robot trained with machine learning by EPFL researchers has learned to avoid falls by spontaneously switching between walking, trotting, and pronking – a milestone for roboticists as well…
Innovation promises to prevent power pole-top fires
Engineers in Australia have found a new way to make power-pole insulators resistant to fire and electrical sparking, promising to prevent dangerous pole-top fires and reduce blackouts. Pole-top fires pose…
Possible alternative to antibiotics produced by bacteria
Antibacterial substance from staphylococci discovered with new mechanism of action against natural competitors. Many bacteria produce substances to gain an advantage over competitors in their highly competitive natural environment. Researchers…
