How a fullerene water suspension kills bacteria: Exploring three possible mechanisms

TOXI 10

Delina Y. Lyon, dlyon@rice.edu and Pedro J. Alvarez, alvarez@rice.edu. Dept. of Civil & Environmental Engineering, Rice University, MS317, 6100 Main St, Houston, TX 77005
The fullerene water suspension, nC60, is a potent antibacterial agent with activity surpassing the bactericide sodium azide. Several eukaryotic studies have implicated reactive oxygen species (ROS) as the mediators of toxicity. However, ROS may not be the only factor responsible for killing prokaryotic cells as the antibacterial activity of nC60 persists in the absence of light and oxygen, challenging the feasibility of photocatalytic ROS formation. Other research on fullerenes suggests that they exert their antibacterial effect via direct damage to the cell membranes. This work explores three possible mechanisms for the antibacterial activity of nC60. It could (1) physically disrupt the cell membrane, (2) generate ROS, or (3) exert ROS-independent oxidative stress. Results from flow cytometry analysis and other analytical techniques point to nC60 acting as a strong oxidant. Defining the antibacterial mechanism allows the manipulation of the antibacterial activity for both disinfection applications and mitigation of undesired environmental impacts.