| Currently, nanotechnology is in the flourishing development period, it will help us to deep understanding of the natural world at the nanometer scale, and give us more profound understanding and awareness of the nature. Many characteristics of the substance in this dimension have been revealed, such as quantum size effect, small size effect and so on. Nanotechnology involves the chemistry, biology, physics, materials science and many other disciplines, which is the hot multi-disciplinary integration area of the research right now. With the gradual deepening of research, the applications of nanotechnology in the many aspects, for example, prevention, diagnosis, and treatment of the disease have been widely explored, which are expected to promote the development revolutionary of analytical chemistry and biomedicine.Quantum dots (QDs), as particles in nanoscale, have excellent fluorescence emission. Since1998, QDs were used for the first time in the field of bio imaging, which opened a prelude to the biological applications of QDs. However, the QDs such as CdSe, CdTe have been widely used in the early age, and compared with traditional organic dyes, QDs have many advantages, but also accompanied by some insurmountable difficulties, the most prominent question is the bio-security. As a result, people began to turn their attention to look for a new type of QD, which has more biocompatible and without containing cadmium ions.In this work, based on the current research background, novel type of luminescent gold QDs, zinc oxide QDs have been investigated as platforms. Meanwhile, new luminescent nanomaterials with excellent biocompatible, water-soluble, have been synthesized and used in many analytical fields.In chapter1, the research progress of luminescent gold nanomaterials has been systematic elaborated described, furthermore, this chapter reveals the in-depth understanding course of the luminescent gold nanomaterials, and summarized of the preparations, characterizations, properties and applications of gold QDs. A detailed summary of research progress of zinc oxide QDs also has also been fulfill discussed, plus, the common design strategies for controlled drug delivery system have been summarized as well. According to the summary of the literatures, the subsequent experiments including design and carried out will have a good foundation.In chapter2, by using a microemulsion method, new silica wrapped gold QDs luminescent nanocomposites have been prepared, such nanocomposties have good water-soluble, luminescent properties and biocompatibility. At the same time, their surfaces are very easy to functionalize with the help of silylating reagent. In addition, the products can be very easy to centrifugal separation from the solution, which will facilitate the next operation of the experiments. By grafting the functional folic acid molecules in the experiment, the surface of the nanocomposites can be modified, so that they can target identification of the folate receptor overexpressing tumor cells, thus achieves the targeted cell imaging for the cancer cells.In chapter3, a novel method for synthesis of wavelength-tunable luminescent gold QDs has been developed, that is, by adjusting the different mixing ratio of11-mercaptoundecanoic acid and D-penicillamine, and the different ratio organic molecules were reacted with as-prepared gold seeds solution under certain conditions. Then the different wavelength emission gold nanoparticles can be obtained, this is a very innovative method for the preparation of multi-wavelength luminescent gold QDs. Furthermore, the obtained products have been fulfill characterized, including ultraviolet spectroscopy, fluorescence spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, which provide a strong experimental basis for the further in-depth understanding of the principle of gold luminescence. At the same time,11-mercaptoundecanoic acid, glutathione, L-cysteine and3-mercaptopropionic acid were also researched in the experiment, and the results reveal that only the L-cysteine molecules mixed with11-mercaptoundecanoic acid in a certain proportion could cause the similar phenomenon. This result suggests that the amino, thiol groups as well as the distance between them play significant factors in the present experimental method. In addition, the experiment also investigates the potential value of the resulted products in the cell imaging, as well as the cell viability has also been tested.In chapter4, a novel pH responsive drug delivery system is constructed in this work, which is based on the pH-sensitive property of zinc oxide QDs as nanocarriers for loaded of drug molecules of doxorubicin hydrochloride (DOX). This new drug system is relatively stable under physiological conditions (pH7.4), but decomposed in acidic conditions, so that the nanocarriers release the drug molecules of DOX. This novel drug delivery system has a variety of advantages, for example, compared with commonly used mesoporous silica drug delivery system, it has a higher drug release rate, as well as relatively easy to clear from body by the physiological metabolism. This experiment also investigates the controlled release process in vitro and the treatment effects for human glioblastoma cells, the results reveal that the new drug delivery system has good ability for killed cancer cells, and its exhibit pH controllable drug release. Hence, this found will be helpful for the chemotherapy in the future works, and provides a new way of thinking about how to reduce the side effects.In chapter5, a comprehensive summary of the works has been done at first. Next, based on the experience accumulated in the progress of the experiments, as well as the research found in the literature, some research directions are exhibited for the further investigation, and these proposed problems are expected to be solved one by one. So that the understanding of gold QDs, zinc oxide QDs will be greatly enriched, and benefit for our mankind ultimately. |
PDF Full Text Request