School of Chemistry and Environmental Engineering, Wuhan Institute of Technology, Wuhan 430073, China; College of Materials and Chemical Engineering, Pingxiang University, Pingxiang 337055, China.
School of Chemistry and Environmental Engineering, Wuhan Institute of Technology, Wuhan 430073, China.
Int J Biol Macromol. 2023 May 15;237:124255. doi: 10.1016/j.ijbiomac.2023.124255. Epub 2023 Mar 29.
Chitosan as the plentiful and easily available natural polymer, its solubility in organic solvents is still a challenge. In this article, three different chitosan-based fluorescent co-polymers were prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization. They could not only dissolve in several organic solvents, but also could selectively recognize Hg/Hg ions. Firstly, allyl boron-dipyrrolemethene (bodipy) was prepared, and used as one of the monomers in the subsequent RAFT polymerization. Secondly, chitosan-based chain transfer agent (CS-RAFT) was synthesized through classical reactions for dithioester preparation. Finally, three methacrylic ester monomers and bodipy bearing monomers were polymerized and grafted as branched-chains onto chitosan respectively. By RAFT polymerization, three chitosan-based macromolecular fluorescent probes were prepared. These probes could be readily dissolved in DMF, THF, DCM, and acetone. All of them exhibited the 'turn-on' fluorescence with selective and sensitive detection for Hg/Hg. Among them, chitosan-g-polyhexyl methacrylate-bodipy (CS-g-PHMA-BDP) had the best performance, its fluorescence intensity could be increased to 2.7 folds. In addition, CS-g-PHMA-BDP could be processed into films and coatings. When loading on the filter paper, fluorescent test paper was prepared and it could realize the portable detection of Hg/Hg ions. These organic-soluble chitosan-based fluorescent probes could enlarge the applications of chitosan.
壳聚糖作为一种丰富且易得的天然聚合物，其在有机溶剂中的溶解性仍然是一个挑战。本文通过可逆加成-断裂链转移（RAFT）聚合制备了三种不同的壳聚糖基荧光共聚物。它们不仅可以溶解在几种有机溶剂中，而且可以选择性地识别 Hg/Hg 离子。首先，制备了烯丙基硼二吡咯甲川（bodipy），并将其用作随后的 RAFT 聚合中的单体之一。其次，通过经典的二硫酯制备反应合成了壳聚糖基链转移剂（CS-RAFT）。最后，将三种甲基丙烯酸酯单体和带有 bodipy 的单体分别聚合并接枝到壳聚糖上作为支链。通过 RAFT 聚合，制备了三种壳聚糖基大分子荧光探针。这些探针可以很容易地溶解在 DMF、THF、DCM 和丙酮中。它们都表现出对 Hg/Hg 的“开启”荧光，具有选择性和灵敏的检测性能。其中，壳聚糖接枝聚己基甲基丙烯酸酯-bodipy（CS-g-PHMA-BDP）的性能最好，其荧光强度可增加到 2.7 倍。此外，CS-g-PHMA-BDP 可以加工成薄膜和涂层。当负载在滤纸上时，制备了荧光试纸，可以实现 Hg/Hg 离子的便携式检测。这些有机溶剂可溶性壳聚糖基荧光探针可以扩大壳聚糖的应用。
