Click Synthesis Of Novel Aggregation Induced Emission Cyclodextrin Fluorescence Sensors And Their Application

Fluorescent materials play an important role in the study of sensors and optoelectronic devices.Traditional fluorescent sensors severely limited its application in the field of detection due to the aggregation of fluorescence quenching phenomenon(ACQ).In 2001,Tang et al first reported the aggregation induced emission(AIE)characteristics,molecules with AIE activity have no fluorescent property in solution due to the non-radiative decay caused by intramolecular motions,whereas they become highly emissive on aggregation state since the intramolecular motions are restricted,which provides a new way to design solid material with high fluorescence quantum yield.The feature of the AIE compounds,make it widely used in the field of molecule,ion and biological macromolecules detection as fluorescent probes.Tetraphenylethylene(TPE)compounds based on easy modification and synthesis,high fluorescence quantum yields,have become the stars of AIE molecules.On a separate note,the small optical coherence and good biological compatibility of Cyclodextrin(CD)make it have the potential applications value in the field of molecular recognition,optical materials and bio-pharmaceuticals.The current thesis reports the successful construction of AIE compounds with TPE hydrophobic fluorescent unit and CD hydrophilic groups via click strategy.And explore the potential application of the moleculars in heavy metal ions detection.(1)Based on the Cu(I)catalyzed 1,3-dipolar cycloaddition(click chemistry),we combined the mone alkynyl-TPE with momo azide-CD to design and synthesis a novel triazole bridged fluorescence probe(TPE-Triazole-CD)with good coordination ability,which realized the highest sensitivity and selectivity detection of Cd2+ in neutral environment.Among several common soluable organic solvents,TPE-Triazole-CD showed excellent AIE properties,and the Cd2+ can significantly trigger the aggreagation of fluorescence probe,which limit the rotation of benzene rings,act as an excellently selective turn-on fluorescence sensor.Fluorescence titration and Job’s plot curve confirmed the possible complex ratio of TPE-Triazole-CD and Cd2+ is 2:1.The new material exhibits excellent selective turn-on fluorescence response to Cd2+ in neutral environment with a low detection limit of 10 nM.(2)On the basis of our previous work,in this paper,we developed “a one-pot click reaction” to simultaneously prepare a novel cyclodextrin dimer based aggregation induced emission sensor(TPE-2Triazole-2CD)and monomer based chiral stationary phase(Triazole-CD-CSP).The TPE-2triazole-2CD has good selectivity to Zn2+ in system of DMSO/H2 O,Fluorescence titration and Job’s plot curve confirmed the possible complex ratio of TPE-2Triazole-2CD and Zn2+ is 3:1.In addition,the obtained Triazole-CD-CSP can achieve efficient enantioseparation of chiral compounds,such as dansyl leucine(Dns-Leu)and dansyl methionine(Dns-Met)and so on.In this thesis,we firstly developed an effective approach for the fabrication of novel TPE-CDs fluorescence probe,which is significant to the design and fabrication of novel functional materials based on aggregation induced emission.