Preparation of a responsive carbohydrate-coated biointerface based on graphene/azido-terminated tetrathiafulvalene nanohybrid material.

A one-step method for the reduction of graphene oxide (GO) to reduced graphene oxide (rGO) is reported taking advantage of the electron-donor properties of an azido-terminated tetrathiafulvalene (TTF-N(3)). The resulting graphene/TTF-N(3) nanohybrid material is characterized by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR) spectroscopy, and by electrical and electrochemical means. The accessibility of the azide function to chemoselective modification by any alkyne-terminated partner molecule via Cu(I)-catalyzed "click" chemistry is demonstrated. In a proof of principle and motivated by the importance of glycan-modified materials, many alkynyl-terminated mannose units were grated onto graphene/TTF-N(3). The TTF-mannose units could be released efficiently from the graphene matrix by chemical oxidation of TTF-mannose surface units to TTF(2+)-mannose, using Fe(ClO(4))(3) or the electron-deficient tetracationic cyclophane cyclobis(paraquat-p-phenylene) (CBPQT(4+)).