Non-covalent modified multi-walled carbon nanotubes: dispersion capabilities and interactions with bacteria.
M. Khazaee, D. Ye, A. Majumder, L. Baraban, J. Opitz, and G. Cuniberti
Biomedical Physics & Engineering Express 2, 055008 (2016)
Antimicrobial activity of surfactant-modified multi-walled carbon nanotubes (MWCNTs) was investigated by analyzing the growth curves of an Escherichia coli (E. coli) population in ionic and non-ionic surfactant-modified MWCNTs in Luria Bertani (LB) broth. The ionic surfactants (sodium dodecylbenzenesulfonate (SDBS), sodium cholate (SC), dodecyltrimethylammonium bromide (DTAB), cetyltrimethylammonium bromide (CTAB)) as well as a non-ionic polyvinylpyrrolidone (PVP) were used to test the dispersion and resulting antimicrobial effect of MWCNTs by means of UVñvis spectroscopy and optical density (OD) measurement. Among these surfactants, SDBS and DTAB provided maximum and minimum MWCNT dispersion, respectively. Furthermore, the biocompatibility issues with respect to dispersion capabilities of the ionic and non-ionic surfactants is discussed in detail, as a source of potential misinterpretation of the obtained growth curves of E. coli and thus, their antimicrobial effect. Finally, scanning electron microsco py was used to study the interaction of well-dispersed MWCNTs with the E. coli cells.