Synthesis And Characterization Of Inorganic Nanomaterials Based On Polypeptide

The fabrication of novel nanomaterials with interesting morphologies and specific structure has become a new focus for chemists and materials researchers. It is important for biological sensors and cellar imagings to synthesize water-soluble and biocompatible nanomaterials with novel optical, electronic and mechanic properties, to study the relationship between their properties and structures, and to investigate the interaction rules between them and biological molecules. This thesis is an aim to synthesize good water-soluble and biocompatible polypeptide and polypeptide/ inorganic nanocomposites, to study their optical properties and the interaction with biological molecules, and to set up a new method of detecting biological molecules selectively. 1,Polycystine were prepared by solid-state polycondensation reaction under the irradiation of infrared heat lamp, and characterized by transmission electron microscopy, X-ray powder diffractometer, UV-vis spectroscopy, Fluorescence spectroscopy and FT-infrared spectroscopy. Polycystines self-assemble as micro rods in water, nanoneedles in alcohol and large needles in the mixture of little water and much acetone. 2,Polycystine / multi-walled carbon nanotubes (MWNTs) composites were prepared by solid-state polycondensation reaction under the irradiation of infrared heat lamp, and were characterized by transmission electron microscopy, X-ray powder diffractometer, UV-vis spectroscopy, Fluorescence spectroscopy and FT-infrared spectroscopy. The composites can be dispersed in water easily to form a homogeneous solution, and its solubility was about 7 mg/ml without the ultrasonic agitation. It can remain in aqueous solution for a long time and no precipitation could be observed after one month. This may open the way to a high number of opportunities, such as improving the interactions between MWNTs and polymer by the hydrogen bond, the dispersion of MWNTs in composite and the compatibility with biological systems. 3,CdSe nanoparticles modified by glutathione with different colors were synthesized via reduction reaction in water, and characterized by transmission electron microscopy, X-ray powder diffractometer, UV-vis spectroscopy, FT-infrared spectroscopy and Fluorescence spectroscopy. The synthesis method is simple and quick. CdSe nanoparticles obtained have a ca.150 nm broad, continuous excitation peak and a narrow, symmetric emission peak. The CdSe nanoparticles modified with glutathione are compatible with biological macromolecules. Not only the fluorescence intensity enhanced but also the peak had blue-shift about 60 nm when glutathione modified CdSe nanoparticles were reacted with ct-DNA, meanwhile, the fluorescence of the glutathione modified CdSe nanoparticles is quenched in the presence of Stomach Mucosa and its intensity is enhanced only in the presence of fs-DNA. It will be used as fluorescence sensors for biological molecules with other inorganic or organic fluorescence molecules and to detect many objects with single excitation.