Antimicrobial photodynamic inactivation with fullerenes bearing cationic charges may overcome resistant microbes. We synthesized C₆₀-fullerene (LC16) bearing decaquaternary chain and deca-tertiary-amino groups that facilitates electron-transfer reactions via the photoexcited fullerene. Addition of the harmless salt, potassium iodide (10 mM) potentiated the ultraviolet A (UVA) or white light-mediated killing of Gram-negative bacteria Acinetobacter baumannii, Gram-positive methicillin-resistant Staphylococcus aureus and fungal yeast Candida albicans by 1–2+ logs. Mouse model infected with bioluminescent Acinetobacter baumannii gave increased loss of bioluminescence when iodide (10 mM) was combined with LC16 and UVA/white light. The mechanism may involve photoinduced electron reduction of ¹(C₆₀>)* or ³(C₆₀>)* by iodide producing I· or I₂ followed by subsequent intermolecular electron-transfer events of (C₆₀>)^–· to produce reactive radicals.