Functionalization of carbon nanotubes regulated with amino acids

A new approach has been developed for the functionalization of multi-walled carbon nanotubes (MWNTs). The self-assembly of a sugar-based amphiphile on MWNTs was carried out in amino acid solutions. The functionalization of MWNTs has been investigated by means of UV–vis, Raman spectra, FTIR, XPS, XRD, and HRTEM. It has been found that amino acids can promote the self-assembly of the amphiphile on MWNTs and regulate the amount and conformation of the assembled amphiphile. The effect of amino acids on the aggregation of the sugar-based amphiphile on MWNTs was analyzed through FTIR spectra. The specific interactions of f-MWNTs with the protein concanavalin A were investigated through the measurement of UV–vis spectra. This work demonstrates that, the functionalized MWNTs with disaccharide groups on their exterior surface have a good dispersibility in water and are biocompatible, and may have a potential application of biomolecular recognition.