The amount of surface oxygen present in graphene materials is an important aspect in determining how successful they can be in killing bacteria—a breakthrough that might aid in developing safer and more efficient products to fight antimicrobial resistance.
New discovery about graphene materials may help to design safer and more effective products to fight antimicrobial resistance. Image Credits: University of Birmingham
Graphene oxide that has high surface oxygen content (SOC) is extremely flexible and can wrap around bacteria (a parallel mode of contact). However, when it has less SOC, the material will have increased rigidity and will contact bacteria in a perpendicular mode (edgewise).
A global research team from the UK, Cyprus, Austria, Finland, The Netherlands, and China shows that it is graphene oxide’s different interaction modes that result in distinct antibacterial activity—with a “switch” happening when surface oxygen levels reach a particular threshold.
Our research highlights that surface oxygen levels can help to evaluate the antibacterial effects of graphene materials—helping to design safer materials through clarifying the role of SOC.
Dr. Peng Zhang, University of Birmingham
A minor change of SOC can result in the shift of interaction modes among parallel and perpendicular contact.
The impact of SOC on the interaction mode has been underestimated for a long time.
Dr. Zhiling Guo, University of Birmingham
Being antimicrobial, graphene materials might have benefits over conventional antibiotics owing to their physical mechanisms of action, which guarantee a lower likelihood of microbial resistance development.
So far, the basic question as to if the antibacterial mechanism of graphene materials arises from perpendicular or parallel interaction or from a combination of both remains less understood, hampering advancement in designing antibacterial graphene materials and understanding their environmental safety.
Professor Iseult Lynch from the University of Birmingham stated “The discovery is a potential ‘gamechanger’ and we should be using this surface oxygen ‘switch’ as the determining property to define and classify graphene materials in the context of human health and environmental safety.”
Our research highlights that surface oxygen levels can help to evaluate the antibacterial effects of graphene materials - helping to design safer materials through clarifying the role of SOC.
Dr. Peng Zhang, University of Birmingham
The UK-based global research group designed a series of graphene materials with various SOCs and compared their antibacterial performance—assessing total cell growth, oxidative stress, and biofilm formation, along with physical interactions with bacteria including through molecular simulations.
As early as 2010, the antibacterial properties of graphene materials were reported. The material has been employed to make antibacterial fabrics for maternity garments, which could avoid microbial growth on the fabric surface. To make antibacterial masks, graphene-coated nonwoven fabrics were utilized, whilst graphene-based membranes were widely explored for water treatment due to their antifouling activity and ultrafast water transport.