Degradable Carbon Dots from Cigarette Smoking with Broad-Spectrum Antimicrobial Activities against Drug-Resistant Bacteria

Infection of pathogenic bacteria and the abuse of antibiotics are the main factors in worldwide health issues. A number of nanomaterials have been fabricated to directly battle drug-resistant bacteria. However, few studies have referred to the relation between common daily carbon nanoparticles (e.g., automobile exhaust and cigarette smoke) and antimicrobial activities. Herein, carbon dots (CDs) extracted from cigarette smoke are introduced, showing low in vivo and in vitro toxicity. These CDs show broad-spectrum antimicrobial activities that originate from the destruction of the double helix structure of DNA. CDs can degrade to smaller particles and organic fragments with the existence of horseradish peroxidase (HRP) and H₂O₂ in 7 days, during which CDs can function as an effective antibiotic within the early days and then gradually degrade and lose the antimicrobial effects until finally being eliminated through metabolism. Our findings relate common daily carbon nanoparticles from cigarette smoke with antimicrobial activities, suggesting that the CDs can function as an effective broad-spectrum antibiotic, even against drug-resistant bacteria.