Antibacterial nanofabrics that are triggered by light have been made by a team of Czech scientists. 

The group, led by Jirí Mosinger of the Charles University in Prague, attached porphyrin molecules to polymeric nanofibres. When activated by ultraviolet light porphyrins convert oxygen from its usual unreactive state into a highly reactive form called singlet oxygen, which is a very strong oxidising agent.

Mosinger's team tested the material's antibacterial properties by placing sections of the porphyrin-doped nanofabric onto agar plates contaminated by the bacterium Escherichia coli.  Plates that were left in the dark overnight were found to be completely covered in bacterial colonies. But there were no bacteria found on or around the fabric on plates left in the light. The singlet oxygen formed by the light activated porphyrins stopped the bacterial growth.

Jonathan Sessler of the University of Texas, US, said, 'this effect could make these new materials of use in a range of areas where sterility needs to be maintained or enforced, including drug packaging or wound dressings.'

According to Mosinger, 'the nanofabrics are non-polluting materials and the embedded porphyrin sensitizer is non-toxic'. The team hopes that the material will have antimicrobial effects for other pathogens too.

Sophia Anderton