Self-assembly of sugar-based amphiphile on carbon nanotubes for protein adsorption

A new approach has been developed for the non-covalent functionalization of multiwalled carbon nanotubes (MWNTs), which allows a presentation of carbohydrate on their surface by hydrophobic interactions. The approach is based on the self-assembly of a sugar-based amphiphile on MWNTs in alcohol/water mixtures, which has been investigated by means of ultraviolet (UV), Raman spectra, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and high-resolution transmission electron microscopy (HRTEM). It has been demonstrated that alcohols not only can promote the self-assembly of the amphiphile on MWNTs but also can regulate the amount and conformation of the assembled amphiphile. The adsorption of bovine serum albumin (BSA) onto functionalized MWNTs has been studied and characterized with circular dichroism (CD) spectra. The results showed that the conformation of adsorbed BSA has been well preserved. It has been demonstrated that, the functionalized MWNTs with disaccharide groups on their exterior surface have a good dispersibility in water and are biocompatible, may have a potential application of molecular recognition.

► We demonstrate a new method for functionalization of carbon nanotubes.
► The self-assembly of a sugar-based amphiphile on MWNTs is carried out in alcohol solutions.
► Alcohol solutions can promote the self-assembly of the amphiphile on MWNTs.
► Alcohol solutions can regulate the amount and conformation of the assembled amphiphile on MWNTs.
► The functionalized MWNTs (f-MWNTs) have a good dispersibility in water and are biocompatible.
► f-MWNTs may have a potential application of molecular recognition.