Preparation And Characterization Of Novel Mercury Fluorescent Sensor Based On New Hybrid Materials

Recently, with the prosperous development of nanomaterial interdisciplinary science, more and more novel inorganic/organic hybrid materimals based on mesoporous nanoparticle have been fabricated and applied in metal ions detection and removal, intellective drug delivery and bio-imaging. Fe3O4@SiO2nanoparticles have also gained much attention as a magnetically separable carrier, which have very good biocompatibility, renewability, and stability.The first part of this thesis presents the successful synthesis of mercury sensor based on monodisperse and nanometer-sized periodic mesoporous organosilica (PMO) and fluorescence resonance energy transfer (FRET) effect. Anthracene and spirolactam rhodamine are chosen as the energy donor and acceptor of FRET pair, which are located in the framework and pore channel and used as the reference and report units, respectively. Spirolactam rhodamine is non-fluorescent and emissions due to the ring-opening when it coordinates with mercury ions, which is based on the "off-on" mode detection. However, the change of fluorescence emission of spirolactam rhodamine before and after coordinating with mercury ions will change the FRET efficiency between anthracene and spirolactam rhodamine, which leads to the ratiometric detection of mercury ions. The arrangement of the reference and report units of traditional FRET type ratiometric sensor in the framework and pore channel by the self-assembly synthesis process of mesorporous silica avoids the covalent linkage between the two units and effectively simplify the design and preparation process of ratiometric sensor.The second part of this thesis presents the magnetically separable mercury ions sensor by combining magnetic particles with Rhodamine6G dye. Firstly, monodisperse Fe3O4particle was prepared and coated with silica to improve their modifiability and stability. Then, the relationship between the particle size and dispersibility of Fe3O4@SiO2and the amount of TEOS was studied to obtain carrier with appropriate size. Finally, the surface of Fe3O4@SiO2was modified with R6G and the resultant nanoparticles exhibited selective "turn-on" type fluorescent enhancements changes with Hg2+...