Susceptibility constants of Escherichia coli and Bacillus subtilis to silver and copper nanoparticles.

Nanoparticle susceptibility constants were defined and used to evaluate the antimicrobial characteristics of silver and copper nanoparticles against Escherichia coli and Bacillus subtilis. Reaction of copper nanoparticles of 100 nm with B. subtilis showed the highest susceptibility (Z=0.0734 mL/microg) whereas the reaction of silver nanoparticles of 40 nm with E. coli showed the lowest one (Z=0.0236 mL/microg).