A novel tricationic fullerene C60 as broad-spectrum antimicrobial photosensitizer: mechanisms of action and potentiation with potassium iodide

A novel amphiphilic photosensitizing agent based on a tricationic fullerene C60 (DMC603+) was efficiently synthesized from its non-charged analogue MMC60. These fullerenes presented strong UV absorptions, with broad range of less intense absorption up to 710 nm. Both compounds showed low fluorescence emission and were able photosensitize the production reactive oxygen species. Furthermore, photodecomposition l-tryptophan sensitized by both indicated an involvement type II pathway. DMC603+ effective produce photodynamic inactivation (PDI) Staphylococcus aureus, Escherichia coli Candida albicans. Mechanistic insight that action mainly mediated photoprocesses in bacteria, while greater preponderance pathway found C. In presence potassium iodide, potentiation PDI observed due formation iodine Therefore, can be used as potential broad-spectrum antimicrobial photosensitizer.