Abstract : The aim of the present work was to functionalize fluorescent nanodiamond by covalent
grafting with hyperbranched polyglycerol. Fluorescent nanodiamond, derived from high
pressure high temperature diamond microdiamond, was oxidized then thermally reacted with
pure glycidol in the absence of catalyst. Thermal polymerization of glycidol was notably
faster on the nanodiamond surface as a result of a surface initiation of the isothermal ring
opening polymerization. Interestingly, the aqueous dispersion of the resulting nanoparticles
appeared stable at high ionic strength. Furthermore, the fluorescent nanodiamond grafted with
hyperbranched polyglycerol displayed several hydroxyl end–groups which could be further
derivatized by carboxylation or carbamatization and subsequently conjugated with protein
linked via an amide bound. Notably, nanodiamonds retain their unique fluorescent
characteristics. This work suggests that fluorescent nanodiamond coated with hyperbranched
glycidol could be promising in biomedical research where aqueous dispersion of fluorescent
nanoparticles stable in physiological medium are in high demand to label, track and quantify
biomolecules.
