A new material can eliminate bacteria and viruses —all it needs is light
Killing bacteria using light. That’s how simple surface disinfection could become in the future. That’s why scientists from EMPA (Swiss Federal Laboratories for Materials Science and Technology), CATRIN at Palacký University, and the Centre for Energy and Environmental Technologies (CEET) at VSB–TUO have begun developing a special coating whose antimicrobial effect can be activated by infrared light. This material is also gentle on the skin and environmentally friendly – and it could become a new weapon in the fight against antibiotic-resistant bacteria. Its first practical use is currently being prepared in the field of dentistry. The results were published in the journal EcoMat.
A novel material that is eco-friendly, biocompatible, and metal-free is designed to rapidly and locally eliminate microorganisms. It is based on polyvinyl alcohol—a biocompatible plastic commonly used, for example, in the food industry. “A specially synthesized, nitrogen-enriched graphene acid has been incorporated into this matrix. Thanks to its chemical properties, it has significant antimicrobial potential. Its full effect is unleashed when exposed to near-infrared light. The material then employs a dual strategy: it converts light energy into heat, which kills bacteria, and at the same time generates oxygen radicals that disrupt the membranes of pathogens,” explained Radek Zbořil from CATRIN and CEET.
The advantage of this approach is that it works entirely differently from conventional antibiotics. The material thus protects against a wide spectrum of microorganisms without contributing to the development of resistance. “Our laboratory tests clearly confirmed the material’s effectiveness against both bacteria and viruses. Surfaces that frequently come into contact with infectious agents—such as door handles in hospitals or furnishing in operating theatres—are particularly well-suited for this innovation,” said Giacomo Reina from EMPA.
The first practical use of the new coating is being developed for dental medicine. EMPA is collaborating with the Center for Dental Medicine at the University of Zurich to develop a dental splint with firmly embedded graphene acid. Since near-infrared light penetrates several centimetres into tissue, the splint can be placed in the mouth, repeatedly activated by an external light source, and used to destroy microorganisms inside the oral cavity. Oral microflora is an especially tough opponent—complex bacterial communities hide in hard-to-reach niches, protected by layers of their own mucus. Antibiotics and conventional disinfectants struggle to penetrate these biofilms. This allows bacteria to damage teeth or even cause serious infections elsewhere in the body.
Antibiotic-resistant bacteria and emerging viruses pose an increasingly serious threat to the global healthcare system. They are associated with approximately 5 million deaths annually, with the COVID-19 pandemic alone accounting for over 20 million fatalities. Scientists are therefore seeking new strategies to combat these pathogens. One of their goals is to prevent the spread of resistant bacteria and viruses through smart materials and technologies.