Visible Light Sensitized Inactivation of MS-2 Bacteriophage by a Cationic Amine-Functionalized C60 Derivative

Recently, we reported the successful synthesis of various hexakis C-60 derivatives (i.e., C-60 with six functional groups containing NH3+-, CO2H-, or OH-terminals) with enhanced stability in water for aqueous phase application (Lee et al., Environ. Sci. Technol. 2009, 43, pp 6604-6610). Among these newly synthesized C-60 derivatives, the cationic hexakis C-60 derivative with amine functionality, C601CR216(R= CO2(CH2)(2)NH(3+)CF3CO2-1, was found to exhibit remarkable efficiency to inactivate Escherichia coliand MS-2 bacteriophage under UVA irradiation. Herein, we report that this amine-functionalized C-60 derivative is also photoactive in response to visible light from both commercial fluorescence lamps and sunlight. Efficient production of '02, facile reaction of 102 with proteins in MS-2 phage capsid and electrostatic attraction between positively charged C-60 derivative and negatively charged MS-2 phage collectively contributed to high efficiency of MS-2 phage inactivation in this photocatalytic disinfection system. The rate of 102 production was evaluated using a probe compound, furfuryl alcohol, and 102 CT (the product of '02 concentration and exposure time) required to achieve a target level of virus inactivation was quantitatively analyzed. The unique visible-light sensitized virucidal property makes this C-60 derivative highly desirable for the development of sustainable disinfection strategies that do not require continuous chemical addition nor an external energy source other than ambient light.