The Research On The Synthesis And Properties Of Polymer Based Derivatives Of Rhodamine 6G Fluorescent Probe For Hg²⁺

Polymer based fluorescent probe has broad application prospects, such as can be applied to the field of fluorescent markers, biological imaging and sensing. Compared to the small molecule fluorescent probe, polymer based fluorescent probe has obvious advantages, such as good water dispersibility, good biocompatibility, stronger and more stable fluorescence. For polymer based fluorescent probe used in the sensing area, through reasonable design?such as polymerized with other functional monomers? multi-functional given its detection and high sensitivity, the performance and advantages of making them more suitable for practical use than the organic small molecule probes, which is expected to play an active role in environmental detection life science and medicine etc..In this paper, a new Rhodamine 6G-based thiophene derivative R6GDM? functional monomer? were designed and synthesized, and amphiphilic block copolymer P[NIPAM]-b-P[R6GDM] and double hydrophilic block copolymer PEG₁₁₃-b-P [NIPAM-co-R6GDM] obtained by reversible addition fragmentation chain transfer polymerization?RAFT?. Thus, obtained two new kinds of polymer based fluorescent probes, which detection for Hg²⁺ in purely aqueous media. The work of this thesis is divided into two parts:1. Using Soft Hard Acid-Base theory?SHAB? and references to designed and successfully synthesized a novel Rhodamine 6G thiophene derivatives, and through its secondary amine hydrogen react with acryloyl chloride successfully grafted carbon carbon double bonds, Thus, Hg²⁺-highly selective fluorescent functional monomer R6 GDM was obtained, the hydrogen spectrum?1H-NMR? carbon spectra?13C NMR?, and mass spectrometry?ESI-MS? analysis to determine the successful synthesis of functional monomer R6 GDM. Then the functional monomer R6 GDM and N- isopropyl acrylamide?NIPAM? by using continuous RAFT polymerization to synthesize amphiphilic block copolymer P[NIPAM]75-b-P[R6GDM]₅. The structure of the block copolymers was characterized by 1H-NMR, and the determination of the molecular weight and its distribution by GPC. Using DLS and TEM to characterize the P[NIPAM]75-b-P[R6GDM]₅ micellar particle sizedistribution and morphology. Research shows that the micellar aqueous solution of the polymer with high selectivity and sensitivity of the fluorescence response to Hg²⁺, compared to other common metal ions, and in the visible light and ultraviolet irradiation showed strong red and yellow fluorescence, so P[NIPAM]75-b-P[R6GDM]₅ micelles can be used as a fluorescence sensor for Hg²⁺ in purely aqueous media. In addition, fluorescence test shows that the polymer micelles with pH response and temperature response function in a certain range. Therefore, the polymer micelle has potential to become multifunctional chemical sensors.2. Combined with the previous successful synthesis of functional monomer R6 GDM, and aggregated it into the temperature sensitive block P[NIPAM] of double hydrophilic block copolymer PEG₁₁₃-b-P[NIPAM-co-R6GDM]₈₄ by RAFT polymerization.The structure of the block copolymers PEG₁₁₃-b-P[NIPAM-co-R6GDM]₈₄ were characterized by 1H-NMR, and the determination of molecular weight and its distribution by GPC. The research shows that the aqueous solution of the polymer with high selectivity and sensitivity of the fluorescence response to Hg²⁺, compared to other common metal ions, and in the visible light and ultraviolet irradiation were brown and yellow fluorescence, so the aqueous solution of the polymer PEG₁₁₃-b-P[NIPAM-co-R6GDM]₈₄ can be used as a fluorescence sensor for Hg²⁺ in purely aqueous media. In addition through fluorescence test shows that the aqueous solution of the polymer has the pH response function in a certain range, Therefore, he aqueous solution of the polymer PEG₁₁₃-b-P[NIPAM-co-R6GDM]₈₄ has potential to become multifunctional chemical sensors.