Light Irradiation of N‐Doped Graphene Acid: Metal‐Free Strategy Toward Antibacterial and Antiviral Coatings With Dual Modes of Action

ABSTRACT The increasing emergence of antimicrobial resistance and the development of new infective viral strains represent a constantly growing threat. Metal‐based nanomaterials have emerged as promising tools in the fight against bacterial and viral infections; however, the release of metal nanoparticles/ions in clinical applications may cause undesired side effects (allergies, systemic toxicity), reducing their practical use in antimicrobial treatment. Moreover, the metal‐based nanoparticles possess predominantly antibacterial effects, while their antiviral efficiency remains controversial. Thus, the development of metal‐free strategies enabling combined antibacterial/antiviral properties is a significant challenge. Here, we report a strategy based on light irradiation of nitrogen‐doped graphene acid (NGA) possessing dual photothermal and photodynamic modes of action. The antimicrobial activity is activated through a clinically approved near‐infrared (NIR) light source, and both viral and bacterial spreading can be hampered on the coating irradiation on a scale of minutes (5 to 10 min). The developed metal‐free strategy reduced 90.9% and 99.99% for S. aureus and P. aeruginosa , respectively, as well as 99.97% for murine hepatitis virus. Importantly, this research represents a significant advancement in the development of safe, metal‐free, and effective antimicrobial treatments. NGA coatings are safe for skin, showing no sensitization or irritation, and offer significant potential for advanced antimicrobial treatments.