Design,Synthsis Of New Disubstituted Polyacetylene Based Flurescent Sensors And Study Of Recognition Properties

Fluorescent probes is realized mainly through its colour or fluorescence changes for a specific qualitative or quantitative targets,and has several important advantages such as high selectivity, high sensitivity, short reaction times and convenient operation. Considerable research interests have been focused on the development of fluorescent sensors for environmental monitoring and bio-imaging. Conjugated polymer-based fluorescent probes display several important advantages. For instance, signal amplification, easily fabricated into devices and combination of different outputs,CPFs have attracted great attention. Based on this, we have designed and synthesized two kinds of disubstituted polyacetylene-based fluorescent probes, and studied the properties of selective recognition for target compounds. Meanwhile, we made them to fluorescent strips, and achieved some interesting results. All the target compounds obtained were characterized by FI-IR,1H NMR,13C NMR and LC-MS.1. Brief overview of the design principles of fluorescent sensors, the advantages, research history and status of conjugated polymers fluorescent sensors.2. We design and synthesis anew disubstituted polyacetylene P1 bearing carbazole moieties.Iodine as a typical heavy atoms, has high nuclear charge. From the literature, heavy atom effect of I- toward N-atom in carbazole is the presumable reason for the fluorescence quenching. After the addition of I-, which led to the PI fluorescence quenching, and the color of the solution also changed from colorless to yellow. It is well known that the association constants between iodine and mercury ions are very high (8.3x1023 for HgI2 and 6.3lx1029 for [HgI2-).and Pl/I-complexes with Hg2+ can be detected. After the addition of Hg2+, PI/I- fluorescence is restored, as well as solutions from yellow to colorless. In order to further improve the convenience of testing, we made Pl ito fluorescent strips, and succeeded in reporting the presence of trace I- anion. Therefore, P1 could be a visual and fluorometric probe for iodide and mercury with high selectivity.3. By utilizing the postfunctional strategy, We design and synthesis a new disubstituted polyacetylene P2 bearing 2-(pyridine-2-yl)-1H-benzo[d]-imidazole moieties. Due to the electronic or energy transfer, After the addition of Cu2+ ion, the strong luminescent emission of P2 was completely quenched, offering the resultant P2 sensing ability to detect the trace copper ions. Glyphosate is a broad spectrum, nonselective, post-emergence herbicides that is used to kill weeds in farms, parks, and gardens.From the literature, the corresponding complexes formed quickly when Cu2+ ions encountering with glyphosate. After the addition of glyphosate, the fluorescent of P2/Cu2+ could be dequenched. In order to further improve the convenience of testing, we made P2 into fluorescent strips, and succeeded in reporting the presence of trace Cu2+ ion. The preliminary results demonstrated that P2 could be a turn-off-on fluorometric probe for Cu2+ and glyphosate with high selectivitity...