The growing threat of antibiotic resistant superbugs
Antimicrobial resistance (AMR) is one of humanity's greatest threats. As bacteria and other microbes develop increased resistance to the drugs designed to kill them, researchers are racing to find ways to reduce the incidence of bacterial infectious disease.
Copper is one solution. This metal in its ion form has long been found capable to fight different strains of bacteria, including the commonly found golden staph. This is because the ions released from copper's surface are toxic to bacterial cells.
But the process is slow as the releasing of ions from the copper surface is very limited, taking up to four hours to kill about 97% of golden staph. Significant efforts are underway by researchers worldwide to speed up the process.
A novel antibacterial copper for fighting superbugs
Working with our partners at RMIT University, we’ve developed a potent new copper surface that can destroy more than 99.99% of bacterial cells in just two minutes.
The key to this technology lies in its unique, nano- and micro-porous structure. The researchers used a controlled solidification process to make the alloy which arranged the copper and manganese atoms into specific formations. A chemical process was then used to remove the manganese atoms from the alloy, leaving a pure copper surface full of microscale and nanoscale cavities.
The tiny microscale and nanoscale cavities provide a huge active surface area. Consequently, the porous surface pattern also plays a role in allowing copper ions to release faster. And more importantly, the porous pattern makes the copper surface super hydrophilic. This causes water to lie flat on the surface like a film, rather than as droplets. Bacterial cells struggle to hold their form as they are stretched by the surface nanostructure.
Combined, these effects cause the bacterial cells to degrade, leaving them more vulnerable to the toxic copper ions. They also facilitate uptake of copper ions into the bacterial cells.
A range of applilcations
The range of applications for the new material when it is further developed is substantial, and the technology could see application across a range of everyday surfaces including antimicrobial doorhandles and other everyday high touch-point surfaces in schools, hospitals, homes and public transport. It is proposed that it will also have effective application in antimicrobial respirator filters, air ventilation system filters, and in face masks.
Investigations are currently being considered for its effectiveness against SARS-COV-2, the virus that causes COVID-19. Other studies have uncovered that copper may be highly effective against the virus, and the US Environmental Protection Agency has recently officially approved copper surfaces for antiviral uses earlier this year.
This study was initiated in an RMIT-CSIRO PhD program and was subsequently co-funded by the CASS Foundation, Melbourne, Australia.