| It is a hot issue to design and synthesize nanomaterials with controlled compositions, structures and morphologies according to the applicational requirements. The metal nanoparticles with tunable surface plasma resonance (SPR) were intensely attractive for their unique optical properties and their applications in biomedicine, catalysis, electronics, communication and other fields.The aim of this dissertation is to design nanomaterials'structures, to prepare metallic composites with tunable Surface Plasma Resonance (SPR) and to explore their bio-applications. Based on the physical-chemical of nanomaterials, a lot of applications were innovatively developed, such as the cancer therapy, controlled drug release, enhanced efficiency of polymerase chain reaction (PCR), enhanced sensitivity of GO_x biosensor. The main contents of this dissertation were given as following:(â… ) To prepare silver coated polystyrene (PS) microspheres with simple electroless plating method. Traditional electroless plating method normally needs complex multi-steps and is hard to realize completed coating. In this dissertation, the complexation of triethanolamine (TEA) and Ag+ were used here to control the reaction rate. The TEA content can be used to control Ag+ in solution, at the same time, the its weak reducing property can reduce Ag+ slowly to deposit Ag+ on PS spheres. Modified PS spheres were used here as core materials to enhance the Sn2+ adsorption for its negative charge surface. Generally speaking, this method was simple and the silver shell was complete. This approach can also extend to other metallic-dielectric coating systems.(â…¡) Preparations of novel multifunctional gold nanoshells. Based on the preparation of gold shell coating on silica spheres, gold shells coating on PS was innovatively synthesized and chitosan (CS) was used as functional agent here. This method was not only more biocompatible than those methods using saline coupling agents, but also simple than traditional layer by layer method. At the same time, these gold nanoshells can be easily treated to hollow structures. Besides this, the experimental results showed this material can work as anti-tumor controlled drug release vehicle because of the pH sensitivity of CS.Based on this work, the gold shells coating ball-in-ball spheres were innovately synthesized. One important character of this material is its much higher specific surface area to adsorb drug molecular; at the same time, by controlling the outer ball size and inner ball size, the drug loading capacity can be controlled. Concerned its excellent tunable SPR property, this material also can work as a multifunctional nanomedicine to combine photothermal therapy and chemotherapy. Presently, the prepared parameters were matured and we can produce it in a gram scale. Therefore, this material has a good prospective in many fields.(â…¢) Exploring the advanced biomedicine applications of metal nano-composite with tunable SPR peak. Based on the work of step2, I paid much attention on the cancer therapy by using these metal nano-composites. At present, few in vivo studies were reported using this kind of materials. In our study, the Lewis lung carcinoma was set as a tumor model. The in vivo photothermal therapy of Lewis lung carcinoma in Balb/c mouse using gold shells coating PS was studied. This tumor model was malign, complex and hard to heal. After our in vivo photothermal therapy, the inhibition rate of this material on Lewis lung carcinoma can reach 55%. This research direction has not only a deep theory meaning, but also a bright future in biomedical applications.The effect of gold nanoshells on PCR was also studied in this dissertation. PCR is a molecular biotech to make a huge number of copies of a gene. In recent years, how to amplify the PCR efficiency is a hot issue. Gold nanoshells are innoxious, biocompatible and easy to be functionalized. In our study, the gold nanoshells with different contents have enhancement or inhibition effects on PCR process disciplinarily. Based on the effect of gold nanoshells with ssDNA, the effect of gold nanoshells on bacteria transformation is also studied. Bacterial transformation is the process by which bacterial cells take up naked DNA molecules. If the foreign DNA has an origin of replication recognized by the host cell DNA polymerases, the bacteria will replicate the foreign DNA along with their own DNA. Our study showed gold nanoshells can enhance this transformation efficiency in short time. (â…£)Initiative study photoelectricity effect of gold nanorods on GO_x biosensor. In this paper, we present the effects of NIR (near infrared) light on the immobilization of glucose oxidase (GO_x) with gold nanorod solution. With the development of nanotechnology, minimizing biosensor, enhancing its sensitivity and amplifying its testing objects using nanoparticles are main directions of biosensor. This study not only reveals a higher current response of GO_x biosensor enhanced by gold nanorod, but also shows the modulation of biosensor by photothermal effect based on the surface plasma resonance (SPR) of gold rod. It's the first time to reveal this phenomenon in biosensor as far as we know and this process may improve our understanding about of electron transition dynamics in biosensor and also open a new door to change the electron transition ways.
|
PDF Full Text Request