Formation and properties of a novel complex composed of an amylose-grafted chitosan derivative and single-walled carbon nanotubes

The water-soluble chitosan derivative grafted with short amylose chains (Chit-Amy-III) was synthesized through the phosphorylase-catalyzed enzymatic polymerization, following that the chitosan was grafted with maltoheptaose residues by reductive amination. The chemical structures were characterized by FTIR, 1H NMR, Raman, XRD and static light scattering analyses. The results indicated that the amylose chains were conjugated with the chitosan backbone through the reductive Shiff base bonds (-CH-NH-), and the polymerization degree of the grafted amylose chains was about 25. The dispersion stability of single-walled carbon nanotubes (SWNTs) in water was improved through the complexation of Chit-Amy-III derivatives with SWNTs. Raman, XRD and TEM analyses confirmed that the resultant Chit-Amy-SWNTs complex was formed by the wrapping of the Chit-Amy-III derivative around the SWNTs. The results of electrochemical analysis indicated that the Chit-Amy-SWNTs complex modified electrode displayed excellent electron conductivity and electrocatalytic activity on H2O2.