Study Of Optical Sensor Based On Silica As A Carrier

Nanomaterials are of the unique characteristics. In recent years, various nanomaterialshave been considered as nice materials for biomedical applications. Small size, largesurface area, quantum confinement, and unique magnetic as well as optical propertiesmake nanomaterials to be good materials for both diagnostic and therapeutic fields inthe future. In addition, functional nanomaterials have unique chemical properties.They are suitable for the design of multifunctional nanosystems. The nanosystems canincorporate different nanoparticles with distinct properties into one particle, and thiskind of nanosystem has many advantages compared to individual componentnanomaterial. These novel nanoplatforms could simultaneously accomplish severalgoals, e.g., controling the release of therapeutics, multimodal imaging, specifictargeting, simultaneous diagnostics and therapy. The process that multiplenanomaterials are integrated into a single nanoparticle requires the control ofnanoparticles properties. One or several distinct nanomaterials can be encapsulatedwithin, assembled on, or combined both inside and on the surface of silicananoparticles using different methods to prepare multifunctional nanoparticles.Therefore, among all kinds of nanomaterial systems, the nanoparticle systems basedon silica nanoparticles have attracted a great deal of attention. Silica nanoparticleshave been taken great attention since they exhibit low cytotoxicity, goodbiocompatible, easy synthesis, splendid stability, low cost and easy modification.This dissertation includes three chapters, and the main research work issummarized as follows:In Chapter I, several topics was simply introduced, including the type ofnanomaterials, silica composite, fabrication strategies for nanoparticle systems andthe application of silica-based nanoparticles.In Chapter П, the preparation and characterization of silica nanoparticles weredescribed in detail. Three different synthesize methods of quantum dots was discussedand compared. In addition, the preparation of silica composite was also discussed.In Chapter III, the preparation and characterization of silica composites wasintroduced. The system based on the rhodamine derivative for the determination ofHg2+was established. The experimental results shows that the system is reversible, highly sensitive, and the fluorescence intensity is linear with the concentration ofHg2+in certain rang. Furthermore, the reaction mechanism is discussed in the chapter.The established method has been applied in water samples with satisfied results.