According to scientists a simple hand-held torch-like device can swiftly kill dangerous bacteria, offering a potential boon for emergency workers battling infection risks in wars or disaster zones. The device was created by an international team of researchers from China’s Huazhong University of Science and Technology, Australia’s CSIRO Materials Science and Engineering, the University of Sydney and the City University of Hong Kong.
The “plasma flashlight” delivers a charged, or ionised, jet of gas to zap germs, a team of researchers in China, Australia and Hong Kong said in their study. Hot plasma sterilisers are already used to disinfect surgical instruments, but they are expensive, refrigerator-sized devices that operate at high temperatures. Sterilisers that operate at cooler temperatures require external power such as a wall electrical supply or a generator, as well as a gas feed, in order to keep working. But the new device is driven by a 12-volt battery and does not need a gas feed, according to the study. The study appears in a British publication, the Journal of Physics D: Applied Physics.
According to the inventors they tested it on a thick mat or biofilm of up to 17 layers of Enterococcus faecalis, a germ that is resistant to heat treatment and antibiotics, sometimes causing infections in dental surgery. Biofilm is formed by bacteria to resist treatment and is very difficult to kill, even with intense heat, Prof Ostrikov said. “That’s why alternative approaches like this plasma are sought after,” Prof Ostrikov told AAP. In the experiment, five minutes of exposure to the plasma ray burned through 25 micrometres of 17 different layers of bacteria. The plasma not only inactivated the top layer of cells, but penetrated deep into the very bottom layers to kill the bacteria.