Other nanoscale materials which have been shown to have antimicrobial properties include nanoparticles based on magnesium oxide, copper and copper oxide , zinc oxide, cadmium selenide/telluride and chitosan , as well as carbon nanotubes .
Several of these studies are targeted specifically at food or food packaging applications, and a recent publication reviewed the numerous classes of nanomaterial antimicrobials targeted for use in drinking water sterilization.
In another system, researchers replaced the sodium ions of montmorillonite nanoclays with silver ions and showed antimicrobial activity of these silver nanoclays when dispersed in poly(ε-caprolactone) ; nanoclays modified with silver have also been dispersed in poly(lactic acid) to similar effect.
Note that complex nanoscale architectures with antibacterial activity have also been developed; for example, Ho et al. covalently attached vancomycin molecules to the surface of gold nanoparticles and showed that they have killing power more potent than vancomycin on its own, even against vancomycin-resistant bacterial strains, and Yang et al. functionalized lysozyme-coated polystyrene nanoparticles with selective antibodies and demonstrated efficient bactericidicity against the common food pathogen L. monocytogenes.
Finally, Bi et al. loaded carbohydrate (phytoglycogen) nanoparticles with nisin (a broad-spectrum antimicrobial peptide produced by Lactococcus lactis during fermentation which is frequently used during the manufacture of processed cheeses, meats and beverages) and showed that they exhibit sustained antimicrobial activity against plated L. monocytogenes with efficacy that lasts several times longer than free nisin.