Preparation and characterization of chitosan-grafted multiwalled carbon nanotubes and their electrochemical properties

A chitosan (CS)-grafted multiwalled carbon nanotubes (MWCNT) composite (CS-MWCNT) was prepared via covalently grafting a biocompatible polymer CS onto the surfaces of MWCNT and was characterized by Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible spectroscopy (UV–vis), and transmission electron microscopy (TEM). The interaction between MWCNT and CS was investigated and explained according to the FTIR and UV–vis results. More evidence for the presence of the CS-MWCNT was confirmed by TEM images. In the TEM images, a core-shell structure with nanotubes in the center and a CS layer lying around them was observed. The electrochemical properties of the CS-MWCNT were characterized by an electrodeposition method that involves depositing it on a Au electrode. The porous microstructure of the CS-MWCNT modified electrode was observed by scanning electron microscopy. The excellent electrocatalytic ability of the CS-MWCNT modified electrode towards hydrogen peroxide is applicable to the development of oxidase-based amperometric biosensors.