Application Of Thienyl-containing 1,3-butadiene Derivatives With Aggregation-induced Emission Characteristic As Chemosensors And Biosensors

The emergence of aggregation-induced luminescence(AIE)molecular systems has fundamentally solved the long-standing issue of aggregation-caused quenching(ACQ),which has plagued organic luminescent materials.At present,the research on AIE molecules mainly focused on the structural design and application of new AIE compounds.Aromatic ring and heteroaromatic ring-substituted butadiene derivatives with the typical AIE effect exhibit excellent mechanical,chemical and biological stimuli responsiveness.Novel AIE materials with diverse heteroaromatic substituents provide a great opportunity to study the properities and application of organic light-emitting materials.In this dissertation,a series of bis-thienyl-bisphenyl substituted butadiene derivatives,namely(1Z,3Z)-1,4-di(4-methoxycarbonyl)phenyl-1,4-di(2-thienyl)-1,3-butadiene(2-TPBDE),(1Z,3Z)-1,4-di(4-methoxycarbonyl)phenyl-1,4-di(3-thienyl)-1,3-butadiene(3-TPBDE),(1Z,3Z)-1,4-di(4-carboxyl)phenyl-1,4-di(3-thienyl)-1,3-butadiene(3-TPBDH)and(1Z,3Z)-1,4-di(4-carboxylate sodium salt)-1,4-di(3-thienyl)-1,3-butadiene(3-TPBDN)were designed and synthesized.2-TPBDE and 3-TPBDE are typical aggregation-induced emission(AIE)luminogens.3-TPBDH exhibits AIE or aggregation-enhanced emission(AEE)character in different solvent systems.However,3-TPBDN does not show any AIE characteristic;2-TPBDE and3-TPBDE show high fluorescence quantum yield in solid state,while the quantum yield of TPBD-COOH are lower than those of 2-TPBDE and 3-TPBDE,and the fluorescence intensity of TPBD-COON is the weakest.The mechanism of the AIE or AEE luminogens could be attributed to intramolecular rotation limited(RIR).The fluorescence intensity of both 3-TPBDE and 3-TPBDH in solution generally decrease with increasing temperature,but their intensity does not show a linear relationship with increasing the temperature.3-TPBDH shows a good solvent effect and its maximum emission wavelength redshifts to long wavelength when the dielectric constant of solvents increase.3-TPBDH and3-TPBDN are complementary acid and base.They could convert to each other easily by adjusting the p H of solution.TPBD-COOH can also respond to certain amino acids in DMSO/water system or DMSO/PBS system.However,the sensitivity and selectivity were rather low due to the weak intermolecular interaction between the probe and amino acids.3-TPBDH showed a single selective and high sensitive water soluble sensor for the rapid‘‘turn-on''detection of Ce ions.It showed a real-time and time-stable detection with a limit as low as 2.269?mol/L,which could satisfy the practical application requirements.The mechanism of this“turn-on”response was because the coordination between3-TPBDH and Ce³⁺ions could limit the intramolecular rotation of 3-TPBDH,which reduced the non-radiative decay and enhanced the fluorescence intensity.Moreover,Ce⁴⁺ions could be distinguished and detected via addition of 1,2-propanediol with a semi-quantitative response.3-TPBDN showed a specific“turn-on”response to albumin bovine V(ABV)in a PBS/water system(PBS fraction of 99%)with a detection limit as low as 0.395?g/m L.Cross-contamination measurements results clearly demonstrates that compound 3-TPBDN showed good selectivity to ABV,and other competitive components in serum induce a fairly low interference effect on this fluorescence assay for ABV,which indicated3-TPBDN processes a potential application for biosensing applications.The response mechanism could be attributed to the hydrophobic and electrostatic interactions between the3-TPBDN and ABV.The hydrophobic interaction is dominant,while electrostatic interaciton also played a coordicated role.Therefore,the 3-TPBDN molecules were cross-linked by the ABV,resulting in the limitation of the intramolecular rotation of3-TPBDN and the“turn-on”response.