The release and cytotoxicity of novel light inducible antimicrobial coatings after incineration

Airborne transmitted as well as multiresistant pathogens can spread rapidly in high traffic enclosed public spaces. Antimicrobial coatings of surfaces are a promising approach limiting the spread of diseases by targeted contact inhibition of microbes. A novel class of light-activated coatings including hydrophobic carbon quantum dots (hCQDs) and up-converter (UPC) are developed for this purpose including Safe-by-Design (SbD) principles. The efficacy against pathogens and the human safety aspects need to be well balanced. In case of fire-related accidents, these additives should not increase flammability, smoke release or the formation of harmful entities. In this work, antimicrobial hCQDs & up-converters are coated onto porous and non-porous substrates, exploring the interplay between substrates and coatings on the release of fume products after incineration. The airborne soot particles were assessed for their polycyclic aromatic hydrocarbon (PAH) content and their potential to cause a pro-inflammatory cytokine response in human lung cells. No significant acute in vitro lung cytotoxicity was detected from nano-coated surfaces after incineration. With this study, an important intermediate goal is reached and provides the rational for further investigations.