Multi-walled carbon nanotubes/epilson-polylysine nanocomposite with enhanced antibacterial activity

Aims: To develop a new nano‐composite of multi‐walled carbon nanotubes (MWNTs) with enhanced antimicrobial activity. Methods and Results: A novel antimicrobial nanocomposite MWNT‐epilson‐polylysine (MEPs)] was synthesized via covalent attachment of epilson‐polylysine on MWNTs with hexamethylene diisocyanate (HDI) as the coupling agent. UV‐visible spectra and Fourier transform infrared spectra (FT‐IR) investigations indicate that MEPs is stable, with epilson‐polylysine leaching effectively eliminated. When compared to MWNTs, the new nano‐composite MEPs exhibits enhanced antimicrobial activities. In 20 mg l^?1 suspensions, significant increases of 72·1, 64·5 and 69% against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus can be observed. The deposited film of MEPs also shows improved antibacterial activities and excellent antiadhensive efficacies against Ps. aeruginosa and Staph. aureus. Conclusions: Epilson‐polylysine functionalization of MWNTs with HDI as the bridge was found to be useful for improving the biocidal activity of MWNTs. Significance and Impact of the Study: The new nano‐composite MEPs with improved antimicrobial activity will substantially facilitate the application of MWNTs as the antimicrobial material such as medical device, food, pharmaceutical process and package.