Preciesely Tailoring Gold Nanorods And Their Applications In Biomedical

Due to their special optical properties, thermal properties and biocompatib ility,gold nanorods(GNR), as an important representative of metal nanoparticles, have beenwidely used in biosensing, biomedical imaging and biomedical treatment etc. However,there are some deficienc ies in the area of GNR application, which are mainly in twoaspects. One is that, until now although there are many kinds of synthetic methods ofgold nanorods, but obtaining GNR with specifically longitude plasmonic resonancepeaks(LSPR) is also a challenge. The other is that in the complex environment, theadvantages were not fully utilized.To solve the above problems, my dissertation carried out the fo llowing work basedon the experience and the success of previous research.1. In chapter2, with the assistance of NH4Br and HCl, we used NaNO2as theoxidizing agent to regulated GNR. The effects of the three agents on oxidizing GNRwere investigated by UV-Vis spectrometer. It was found that increasing the amount ofthe agents would enhance the reaction rate. We also derived the oxidation reactionequation. In order to accurately control the synthesis of gold nanorods, the reactionequation has been simplified and deduced for the regulation of go ld nanoparticles. Itdemonstrated that in the oxidation process, the long axis of the absorption peak of go ldnanorods virus the concentration of nitrite is linear, which is a first-order kinetics.According to the formula, we precisely tuned the the LSPR of GNR through changingthe concentration of NaNO2and the reaction time.2. We studied the effects of GNR with different sizes on the production of reactiveoxygen species from anticancer drug-ICG in chapter3. Firstly, we investigated theimpact of GNR on the anticancer drug ICG and S36002which can be used to measurethe active oxygen. The addition of GNR inhibited the fluorescence of S36002, butunder light illumination, it can make the ICG to produce more active oxygen. At last,we investigated the sizes of GNR on the effect of production of active oxygen fro m ICGand found the GNR with LSPR around812nm have the best promoting results.3. Surface modification of the gold nanorods with large aspect ratio and thebiological Based on the foundation of Chapter3, in order to improve the thermalstability of GNR and promote the loading of ICG on GNR, we first synthes ized GNRwith LSPR at810.5nm and then obtained GNR@SiO2by coating the m with SiO2. We investigated the quality of entering into cells and the impact on the cell vita lity. It wasfound that the GNR@SiO2entered into cells more easily and had less toxicity. Finally,we compared the treatment effect of phototherma l therapy, medical therapy and thecombined therapy. The combined therapy is better than either of them.