Selective carbohydrate–lectin interactions in covalent graphene- and SWCNT-based molecular recognition systems

Two new protein recognition systems have been prepared by covalent functionalization of few-layer graphene and SWCNTs with α-D-mannosyl dendrons. A glycodendron, bearing three mannose moieties on the periphery for effective interaction with the lectin, and an azido group at the focal position, has been connected, by means of a “click” chemistry reaction, to both few-layer graphene and SWCNTs endowed with terminal ethynyl groups. The specific affinity of these systems for concanavalin A was thoroughly investigated by AFM, fluorescence and UV-Vis studies. A very reliable approach was used during the AFM investigation of this kind of hybrids; namely, we were able to capture the same object before and after treatment with ConA, which allowed us to obtain reliable conclusions, in terms of selectivity of the carbohydrate–lectin interactions over the nanocarbon platforms.