Black phosphorus nanoflakes show antibacterial potential

Researchers have developed a nano-thin material with black phosphorus that could be integrated into wound dressings and implants to prevent or heal bacterial infections.

The ball shapes are bacteria and the ‘sheet’ is black phosphorus, under the microscope at RMIT University
The ball shapes are bacteria and the ‘sheet’ is black phosphorus, under the microscope at RMIT University - Aaron Elbourne and colleagues, RMIT University

The innovation has undergone advanced pre-clinical trials and is said to be effective against a range of drug-resistant bacterial cells, including ‘golden staph’.

The new study led by RMIT University and the University of South Australia (UniSA) tested black phosphorus-based nanotechnology as an advanced infection treatment and wound healing therapeutic.

Results published in Advanced Therapeutics show it effectively treated infections, killing over 99 per cent of bacteria, without damaging other cells in biological models.

The treatment achieved comparable results to an antibiotic in eliminating infection and accelerated healing, with wounds closing by 80 per cent over seven days.

RMIT has sought patent protection for the black phosphorus flakes including its use in wound healing formulations, including gels.

RMIT co-lead researcher, Professor Sumeet Walia, said the study showed how their innovation provided rapid antimicrobial action, then self-decomposed after the threat of infection had been eliminated.


“The beauty of our innovation is that it is not simply a coating – it can actually be integrated into common materials that devices are made of, as well as plastic and gels, to make them antimicrobial,” said Prof Walia from RMIT’s School of Engineering.

previous study led by RMIT revealed that black phosphorus was effective at killing microbes when spread in nano-thin layers on surfaces used to make wound dressings and implants such as cotton and titanium, or integrated into plastics used in medical instruments.

According to RMIT, black phosphorus is the most stable form of phosphorus and in an ultra-thin form degrades easily with oxygen, making it ideal for killing microbes.

“As the nanomaterial breaks down, its surface reacts with the atmosphere to produce what are called reactive oxygen species. These species ultimately help by ripping bacterial cells apart,” Walia said in a statement.

The new study tested the effectiveness of nano-flakes of black phosphorus against five common bacteria strains, including E. coli and drug-resistant golden staph.


“Our antimicrobial nanotechnology rapidly destroyed more than 99 per cent of bacterial cells – significantly more than common treatments used to treat infections today.”

Lead researcher from UniSA, Dr Zlatko Kopecki, and his team performed the pre-clinical trials to show how daily topical application of the black phosphorus nanoflakes significantly reduced infection.

“This is exciting as the treatment was comparable to the ciprofloxacin antibiotic in eradicating wound infection and resulted in accelerated healing,” said Dr Kopecki.

“If we can make our invention a commercial reality in the clinical setting, these superbugs globally wouldn’t know what hit them,” said co-lead researcher Dr Aaron Elbourne from RMIT.

To this end, the team is looking to collaborate with potential industry partners to develop and prototype the technology.