Synthesis And Characterization Of Fluorescence Sensor For Detection Of Fluoride Ion

Fluorine occurs naturally in soil, water, plants and animals in tracequantities, as one of the important nonmetal elements. The examine methods forfluoride anions have attracted growing interest in past decades because of thefluoride anion’s established role in dental care, treatment of osteoporosis and anumber of potential adverse impacts, notably dental fluorosis. The developmentof fluorescent sensors and probes for anions has received considerable attentiondue to their important roles in chemical and biological process. However, up tonow, only a few ratiometric fluorescent probes for fluoride ion have been reportedand they suffered some drawbacks such as inconvenient, low sensitivity ornon-aqueous solvent media requirement. In this paper, The very fine fluorescencesensor for detection of fluoride ion was prepared by combineing ATRP withelectrostatic spinning。Firstly, A monomerized fluorescence molecular4-(2-acryloyloxy-ethylamino)-7-nitro-2,1,3-benzoxadiazole (NBDAE) wasprepared with NBD-Cl (4-chloro-7-nitro-2,1,3-benzoxadiazole) as raw material.Then, two kinds of well-defined water-soluble random copolymers, poly(oligo(ethylene glycol) methacrylate-co-NBDAE)(P(OEGMA-co-NBDAE)) andPoly(N-isopropylacrylamide-co-NBDAE)(P(NIPAM-co-NBDAE)), wereprepared by atom transfer radical polymerization (ATRP), withethylbutyl-2-bromoiso-butyrate (t-EBiB) as initiator, and CuBr/bpy as catalyst.And then, the fluorescent sensors electrospinning fibers were prepared viaelectrospinning process in the use of the resulting co-polymer in its blends withPolyvinyl Alcohol (PVA).The copolymers were characterized by1H NMR, GPC, UV-Vis, SEM andfluorescence measurement. The results indicated that molecular-weightdistribution of the well-defined hydrophilic copolymers was narrow. Thecopolymers and corresponding composite mico-nano electrospinning fibers are ofgood fluorescence performance. And the fluorescence quenching of them towardsfluoride ion was studied. It was observed that the fluorescence intensity of thepolymers decreased with the increasing of the concentration of fluoride ion. When the concentration of fluoride ion was100μL/cm2, the fluorescenceintensity decreased to0.2times of initial intensity (without fluoride ion), andcomposite mico-nano electrospinning fibers possess obvious fluorescencequenching phenomenon. This phenomenon of fluorescence quenching to specificion provides a basis for trace concentration detection of ion.