Contribution of arabinogalactan protein to the stabilization of single-walled carbon nanotubes in aqueous solution of gum arabic

Abstract Nowadays, the application of gum arabic has been extended from food industry as a food gum to broad fields including pharmaceutical, personal care and nanomaterials as a versatile agent providing specific physicochemical properties and functional attributes. Despite of its excellent properties, the complex nature of multicomponent of gum arabic may act as an obstacle to understand profoundly its functionality and relevant mechanism in applications. In this study the effect of arabinogalactan protein (AGP), one of the main components in gum arabic, on the stabilization of single-walled carbon nanotubes (SWNTs) in aqueous gum arabic solution has been clarified. By using gel permeation chromatography coupled with multi-angle laser light scattering system (GPC-MALLS), fluorescence spectroscopy, circular dichroism, surface tension measurement and thermogravimetric analysis as well as atomic force microscope and transmission electron microscopy observation, it is found that the adsorption of AGP on the surface of SWNTs contributes to the stability of nanotubes in water by steric hindrance. The AGP physically modified SWNTs also shows improved biocompatibility. The use of AGP for stabilization of SWNTs dispersions may offer advantages of maintaining the initial properties of SWNTs, and providing biocompatibility and highly adhesive interfaces between individual carbon nanotubes and a biopolymeric matrix that are essential for tissue engineering and medical devices.