Covalent Functionalization of Nanodiamonds with Natural Amino Acids and Ascorbic Acids

Nanodiamonds have gained considerable attention nowadays owing to their excellent properties and various applications especially in biomedical field. Nevertheless, the tendency of agglomeration limits further wide applications of nanodiamonds. A biological method was conducted to graft natural amino acids and ascorbic acid on the surface of nanodiamonds. The results of Fourier transform infrared, Raman spectra, Thermogravimetric analysis and X-ray photoelectron spectroscopy indicate that the biomolecules were covalently boned on the nanodiamonds surface. Moreover, dynamic light scattering particle size analyzer and Transmission electron microscopic were conducted to investigate the particle size and morphology of surface modified nanodiamonds, which implies that nanodiamonds functionalized by biomolecules present smaller particle size, less aggregation and stable dispersion in organic solution and aqueous solution as well as phosphate buffer. This may enlarge the applications of nanodiamonds especially in biological area.