Correlation of Carbon Dots' Light-Activated Antimicrobial Activities and Fluorescence Quantum Yield.

This study investigated the photo-activated antibacterial function of a series of specifically prepared carbon dots with 2,2'-(ethylenedioxy)bis(ethylamine) as the surface functionalization molecule (EDA-CDots), whose fluorescence quantum yields (Φ) ranged from 7.5% to 27%. The results revealed that the effectiveness of CDots' photo-activated bactericidal function was correlated with their observed Φ values. The antimicrobial activities of these EDA-CDots against both Gram negative and Gram positive model bacterial species ( and , respectively) were also evaluated under conditions of varying other experimental parameters including dot concentrations and treatment times. Optimization of the bactericidal effect of the EDA-CDots by a combination of the selected Φ, concentration and treatment time was explored, and mechanistic implications of the results are discussed.