Bactericidal activity of chlorine-loaded carbide-derived carbon against Escherichia coli and Bacillus anthracis.

Abstract

The authors investigated the bactericidal activity of high-chlorine-content nanoporous carbide-derived carbon (CDC) against the Gram-positive, spore-forming bacterium Bacillus anthracis and the common Gram-negative enteric bacterium Escherichia coli. Chlorine-loaded nanoporous CDC produced by thermochemical etching of metals and metalloids by chlorination of carbides can retain up to 40 wt % of chlorine. Etching temperature and the structure and composition of carbides allow tuning the porosity of CDC. The CDC chlorine content depends on the synthesis temperature, pore size, and metal carbide used during preparation. It was observed that chlorine-loaded CDC killed up to 100% of exposed E. coli and B. anthracis spores and vegetative cells in a dose and time-dependent manner. CDC containing higher concentrations of chlorine killed bacteria to a greater extent and faster than did CDC containing lesser concentrations of chlorine. The results suggest that chlorine-loaded CDC can be used in several commercial, defense, and industrial activities and processes to kill bacteria.