Spectroscopic/Microscopic Study Of Functional Gold Nanoparticles And Doped Quantum Dots

Nanoparticles have been widely used in catalysis, bio-sensing, bio-medicine, magnetic storage, and fabrication of various new materials because of their quantum size effect, small size effect, surface effect and the macro-quantum tunnel effect. Recently, wih the advancement of fabrication technology of various types of functional nanoparticles and deep understanding of their physical and chemical properties, as well as the development of different kinds of bio-analytical techniques, more and more researchers pay strong attention to the application of nanoparticles in biomedicine. That are hot issues to synthesize multifunctional nanoparticles for disease diagnosis and therapy, and to study the interaction between nanoparticles and cancer cells at single-molecule and single-cell level using optical spectroscopy and imaging techniques with high sensitivity and high spatial and time resolution, which are also the main research direction of our group. So it is necessary for us to prepare or test different nanobio probe and nano-materials. The present study mainly focused on the three following aspects:(1) Synthesis and surface modification of gold nanorod and its biological applicationWe optimised synthesis conditions of gold nanorods and studied their surface modification via layer-by-layer assembly of 11-mercaptoundecanoic acid. We further linked anti-EGFR antibody to gold nanorods, and observed their interaction with HeLa cells using darkfield microscopy. Charateriziation of gold nanorods were performed using UV-Vis, Zeta potential, TEM and optical microscopy. Our data suggested that the gold nanorods prepared could be applied in biomedicine.(2) Effect of silanization of glass surface on the immobilization and assembly of gold nanoparticles and the application of the prepared gold nanoparticles films in immunoassayWe studied the effect of concentration of 3-(trimethoxysilyl)propylamine, the amount of water added, and various post-reaction handling conditions on the immobilization and assembly of gold nanoparticles on the substrate, and to some extent realized controlled preparation of gold nanoparticle assembly. We also investigated their potential application in immunoassay. (3) Optical properties of Mn-doped soluble quantum dots.We compared the optical proeperties of Mu-doped quantum dots and traditional quantum dots using UV-Vis spectroscopy and fluorometry, with the intention of using them as new nanobio probes. Based on the results, we conclude that the optical stability of these soluble Mn-doped quantuam dots need to be improved before they can be used reliably in biomedicine.