SFM300应用资料3

We report on novel type of responsive double hydrophilic block copolymer (DHBC)-based multifunctional
chemosensors to Hg2þ
ions, pH, and temperatures and investigate the effects of thermo-induced micellization on the
detection sensitivity. Well-defined DHBCs bearing rhodamine B-based Hg2þ
-reactive moieties (RhBHA) in the thermoresponsive
block, poly(ethylene oxide)-b-poly(N-isopropylacrylamide-co-RhBHA) (PEO-b-P(NIPAM-co-RhBHA)),
were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. Nonfluorescent
RhBHA moieties are subjected to selective ring-opening reaction upon addition of Hg2þ
ions or lowering solution
pH, producing highly fluorescent acyclic species. Thus, at room temperature PEO-b-P(NIPAM-co-RhBHA) DHBCs
can serve as water-soluble multifunctional and efficient fluorescent chemosensors to Hg2þ
ions and pH. Upon heating
above the lower critical solution temperature (∼36 C) of thePNIPAM block, they self-assemble into micelles possessing
P(NIPAM-co-RhBHA) cores and well-solvated PEO coronas, which were fully characterized by dynamic and static
laser light scattering. It was found that the detection sensitivity to Hg2þ
ions and pH could be dramatically improved at
elevated temperatures due to fluorescence enhancement of RhBHA residues in the acyclic form, which were embedded
within hydrophobic cores of thermo-induced micellar aggregates 快速动力学停流装置与光谱分析系统