Synthesis And Characteristic Of Gold Nanoparticle And Glutathione Modified With Azobenzene

With the development of photochemistry, the photosensitive chromogenic group of azobenzene has been used to modify materials and molecular structure to obtain unique and effective properties, such as polymer, dimmer, molecular switch and so on. Azobenzene and its derivatives have attracted increasing attention in the fields of material science, macromolecular science, chemistry and life science. Azobenzene based compounds with photo-anisotropy and chromogenic properties have good potential applications in the areas of photo-information storage, photo-magnification, account, optoelectronics, photo-control molecule tropism and molecular switch.In this dissertation, we chose 4,4'-diaminoazobenzene as a photosensitive group to investigate the effect of this compound on the self-assembly of gold nanoparticles and glutathione. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), Ultraviolet absorption spectrum and infrared absorption spectrum (IR) were used to characterize the properties of gold nanoparticles and glutathione modified with 4,4'-diaminoazobenzene, especially their self-assembly process before and after UV radiation. The main research results are as follows:Gold nanoparticles modified with 4'4-diaminoazobenzene are photosensitive, irradiated by ultraviolet light, theλ_max of UV-Vis absorption of gold nanoparticles if red shift gradually. The result shows that gold nanoparticles gradually gathered and aggregated in solution. The characterizations of election microscope and DLS are consistent to the results of the UV-Vis spectra.The red shift of UV-Vis absorption is more and more inconspicuous when varying ratios of citrate sodium to [AuCl₄]^- to synthesize gold nanoparticles with different sizes, which modified by 4,4'-diaminoazobenzene and irradiated enough with 365 nm UV light. It shows that the amount of citrate sodium plays an important role on the stability of gold nanoparticles and reduces the chance of combination of amino group of 4,4'-diaminoazobenzene to gold nanoparticles. Azobenzene cis form can come back stable trans form under the conditions of irradiation of visible light or treatment of heat. However, gold nanoparticles modified with 4,4'-diaminoazobenzene, irradiated by 365 nm ultraviolet light still gathered and aggregated by means of treatment of heat or irradiation by visible light. It indicates that the gather and aggregation can prevent azobenzene from cis form to trans form, which makes the cis form of azobenzene more stable.We also investigated the effect of 4,4'-diaminoazobenzene on self-assembly of glutathione primary and observed that the glutathione could form tube assemble in acetate anhydrous, and form rod-like assembly in ethyl acetate after irradiation of ultraviolet light.