Potent antibacterial activity of a novel silver nanoparticle-halloysite nanotube nanocomposite powder

Halloysite nanotubes (HNTs), natural nanotube, have been developed as a support for loading of antibacterial agents. Firstly. HNTs were modified by silane coupling agent (KH-792). And then, modified HNTs were immersed in silver nitrate solution and a complex reaction between the two amino groups of KH-792 and silver ions formed, leading to large clusters on the surface of HNTs. Finally, these silver containing clusters were converted into silver nanoparticles (Ag NPs) with about 5 nm diameter by reduction process. A new antibacterial agent, Ag NPs/HNTs, was characterized by X-ray fluorescence (XRF). X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and scanning transmission electron microscopy-energy dispersive X-ray analysis (STEM-EDX). The antibacterial test indicated that Ag NPs/HNTs showed good antibacterial performance against Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus). (C) 2012 Elsevier Inc. All rights reserved.