A tiny layer of graphene flake can act as a deadly weapon in the fight against bacterial infection, particularly during implant surgery, according to researchers, including one of Indian-origin.

Bacteria travel around in fluids, such as blood, looking for a surface to cling on to. Once in place, they start to grow and propagate, forming a protective layer, known as a biofilm. Operations for surgical implants, such as hip and knee replacements or dental implants, always have an increased risk of bacterial infection. This can also cause the implant to not attach to the skeleton, meaning it must be removed. The research showed that a layer of vertical graphene flakes forms a protective surface that makes it impossible for bacteria to attach.

Instead, bacteria are sliced apart by the sharp graphene flakes and killed. "We want to prevent bacteria from creating an infection. Otherwise, you may need antibiotics, which could disrupt the balance of normal bacteria and also enhance the risk of antimicrobial resistance by pathogens," said Santosh Pandit, a postdoctoral student at the Chalmers University of Technology in Sweden.

Graphene, made up of carbon atoms, is only a single atomic layer thick, and therefore the world's thinnest material. It is made of flakes or films and is 200 times stronger than steel. Coating implants with a layer of graphene flakes can, therefore, help protect the patient against infection, eliminate the need for antibiotic treatment, and reduce the risk of implant rejection, the researchers said, in a paper published in the journal Advanced Materials Interfaces. However, previous studies showed that graphene damaged the bacteria, others that they were not affected.

But, "we discovered that the key parameter is to orient the graphene vertically. If it is horizontal, the bacteria are not harmed," explained Ivan Mijakovic, Professor at the Chalmers University of Technology in Sweden. Moreover, graphene was also shown to benefit the bone cells and the sharp flakes do not damage human cells.