Materials

Special porous copper kills golden staph bacteria 120 times faster

Special porous copper kills go...
A scanning microscope image of the copper, showing comb-like cavities
A scanning electron microscope image of the copper, showing comb-like cavities which in turn have even smaller cavities within each tooth of the comb
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A scanning microscope image of the copper, showing comb-like cavities
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A scanning electron microscope image of the copper, showing comb-like cavities which in turn have even smaller cavities within each tooth of the comb
Images magnified 120,000 times under a scanning electron microscope show golden staph bacteria cells after two minutes on a) polished stainless steel, b) polished copper, and in c) and d), the new micro-nano copper surface
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Images magnified 120,000 times under a scanning electron microscope show golden staph bacteria cells after two minutes on a) polished stainless steel, b) polished copper, and in c) and d), the new micro-nano copper surface

While copper does kill bacteria on contact, it typically takes at least an hour to do the job thoroughly. Such is not the case with an experimental new type of copper, however, which is claimed to eradicate almost 100 percent of harmful bacteria in just two minutes.

Regular copper kills bacteria by releasing ions which punch holes in the microbes' protective outer membranes. It's not an instantaneous process, though, taking anywhere from one to four hours to eliminate nearly all of the bacteria that are present on the metal.

This means that if copper is being used to keep commonly-touched surfaces germ-free, well … a lot of people could touch the surface of an item such as a door handle within an hour. That's where the new copper comes in.

Developed via a collaboration between Australia's RMIT University and CSIRO science agency, it's made by first creating a molded alloy made up of copper and manganese atoms. In an inexpensive chemical process known appropriately enough as "dealloying," the maganese atoms are then removed. What's left over is a porous type of copper, full of micro- and nanoscale cavities where the manganese atoms used to be.

This structure gives it way more surface area than normal smooth copper, allowing it to release ions in much greater numbers. Additionally, whereas water forms into droplets on traditional copper surfaces, it's absorbed and spread out into a thin film on the "special" copper. According to the researchers, this causes each bacterium to get stretched out across the copper, making it easier for the ions to infiltrate its outer membranes.

Images magnified 120,000 times under a scanning electron microscope show golden staph bacteria cells after two minutes on a) polished stainless steel, b) polished copper, and in c) and d), the new micro-nano copper surface
Images magnified 120,000 times under a scanning electron microscope show golden staph bacteria cells after two minutes on a) polished stainless steel, b) polished copper, and in c) and d), the new micro-nano copper surface

"A standard copper surface will kill about 97 percent of golden staph within four hours," says RMIT's Prof. Ma Qian. "Incredibly, when we placed golden staph bacteria on our specially-designed copper surface, it destroyed more than 99.99 percent of the cells in just two minutes. So not only is it more effective, it’s 120 times faster."

The scientists are now investigating how effective the copper is at killing the SARS-COV-2 virus, which causes COVID-19.

A paper on the research was recently published in the journal Biomaterials. Readers might also be interested in a study performed at Indiana's Purdue University, in which a laser etching process was used to increase copper's surface area, boosting its antibacterial effect.

Source: RMIT University

6 comments
6 comments
Bill Fortune
can this pours copper be made pours enough to act as a cleanable HEPA , MERVE - 13 filter ???
Vinny van demon
Flexible anti Covid mask?
FatFrass
Soon we will see copper resistant superbugs.
michael_dowling
Viruses cannot be killed,as they are not lifeforms. They are denatured,which means destroying their protein coat.
Jeff7
Ha - porous copper piping has been installed on NZ houses for many years (to replace the porous plastic piping).
christopher
And what percentage of beneficial bacteria does it kill at the same time? And what about the side-effects? - like the damage to our immune system from never having had the opportunity to develop it naturally ... or the negative consequences to the diversity of our gut microbiomes ...