Cytotoxicity properties of functionalised carbon nanotubes on pathogenic bacteria

Abstract

Nanobiotechnology is a promising field concerned with the using of engineered nanomaterials, which leads to the improvement of new human remedial against pathogenic bacteria modalities. In this work, silver nanoparticles (AgNPs) were prepared by an easy, cheap and low-cost electro-chemical method. The AgNPs were then loaded successfully on to multi-walled carbon nanotubes (MWCNTs) using a modified chemical reaction process. The AgNPs on the MWCNTs were well spread and evenly distributed on the surfaces of the long nanotubes with well-graphitised walls as examined by high-resolution transmission electron microscopy. X-ray diffraction and transmission electron microscopy were used for sample characterisation. Good dispersion of AgNPs was obtained on the surface of MWCNTs, resulting in an efficient reactivity of the carbon nanotubes surfaces. Finally, the antibacterial activity of AgNPs/MWCNTs hybrid was evaluated against two pathogenic bacteria Pseudomonas aeruginosa and Staphylococcus aureus exhibited excellent activity.

Fig. 1

Simplified outline for electrochemical method

Fig. 2

Decoration schematic of AgNPs on the MWCNTs

Fig. 3

TEM images of representative AgNPs formation using the electrochemical method at different magnifications (a) Scale bar = 300 nm, (b) Scale bar = 80 nm

Fig. 4

HRTEM images showing hybrid AgNPs deposited on MWCNTs at different magnifications (a) Scale bar = 100 nm, (b) Scale bar = 20nm

Fig. 5

XRD patterns for (a) Pristine, (b) Functionalised MWCNTs, (c) Ag/MWCNTs

Fig. 6

Antibacterial activity determination of Ag/MWCNTs hybrid at concentrations: 1, 3 and 5 mg/ml by the standard agar method after incubation with (a) P. aeruginosa, (b) S. aureus

Fig. 7

Antibacterial activity of Ag/MWCNT filters on (a) S. aureus, (b) P. aeruginosa

Fig. 8

SEM images after incubation of AgNPs/MWCNTs for 24 h with (a) P. aeruginosa, (b) S. aureus