Diameter dependent antioxidant property of polypyrrole nanotubes for biomedical applications

In this work we investigate the diameter dependent antioxidant activity of polypyrrole (PPy) nanotubes synthesized by the reactive self degrade template method. HRTEM (High Resolution Transmission Electron Micrograph) micrograph confirms the formation of nanotubes with smaller diameter at higher cetyltrimethylammonium bromide (CTAB) concentration. The formation of amorphous PPy is revealed by X-ray diffraction pattern exhibiting its characteristic broad peak centred at 2 theta=25 degrees. Antioxidant activity of the nanotubes has been carried out through the alpha, alpha-diphenyl-beta-picrylhydrazyl (DPPH) assay. All the samples quenched DPPH in a dose dependent manner. The antioxidant activity of the nanotubes enhances with decrease in average diameter of the nanotubes and may be used as a potential candidate for food storage and biomedical applications. (C) 2013 Elsevier B.V. All rights reserved.