UCL develops an antibacterial coating to destroy E.coli and MRSA

Scientists at the University College London have created an antibacterial coating which can destroy E.coli and MRSA under low-intensity ambient light, and published their research in the journal ‘ Nature Communications.’ The journal outlines that the coating is a first-of-its-kind to show antibacterial properties under ambient light conditions of approximately three-hundred lux.

The bacterial coating consists of crystal violet dye and chemically modified gold embedded polymer; when it is exposed to three hundred and twelve lux illumination, the team discovered that a crystal violet polymer, alone, could not kill the bacteria. However, when the gold nanoclusters were implemented, hydrogen peroxide was produced under the low light, breaking down the cell walls of the bacteria.

The coating led to a three-point-three log decrease in MRSA growth after six hours, and a two-point-eight log decrease in E.coli growth after a full day.

Dr Gi Byoung Hwang, first author from UCL Chemistry, stated: “Dyes such as crystal violet are promising candidates for killing bacteria and keeping surfaces sterile as they are widely used to disinfect wounds. When exposed to bright light, they create reactive oxygen species, which in turn kill bacteria by damaging their protective membranes and DNA. This is amplified when they are paired with metals such as silver, gold and zinc oxide. The gold clusters in our coating are key to generating the hydrogen peroxide through the action of light and humidity. Given the clusters contain only twenty-five atoms of gold, very little of this precious metal is required compared to similar coatings, making our coating attractive for wider use.”

Dean of UCL Mathematical and Physical Sciences and senior author, Professor Ivan Parkin, stated: “Other coatings have effectively killed bacteria but only after exposure to UV light, which is dangerous to humans or very intense light sources, which aren’t very practical. We are surprised to see just how effective our coating is in killing both S. aureus and E. coli in ambient light, making it promising for use in a variety of healthcare environments.”