Synthesis And Properties Of Fluorescent Probes For Detection Of F^-,H₂S And H₂O₂ Based On Tetraphenylethene Derivatives

Tetraphenylethene（TPE）is a typical AIE（aggregate induced emission）photoluminescent group due to its helical structure of freely rotating peripheral benzene ring.When TPE aggregates in an undesirable solvent or is subjected to external pressure,the rotation of the single bond connected to the building unit benzene ring is blocked,resulting in intramolecular rotation restriction（RIR）or intramolecular motion restriction（RIM）of the benzene ring,which leads to the bright AIE phenomenon.Its derivatives are widely synthesized and applied by researchers because of their excellent thermal stability,high fluorescence quantum yield,ability to convert ACQ groups into AIE or aggregate induced fluorescence enhancement（AIEE）groups,excellent photoluminescence properties and easy to modify functional groups.In recent years,many important research results have been achieved in the design and synthesis of its derivatives for applications in information storage,chemical sensing,biosensing,organic light emitting diodes（OLEDs）,optical anti-counterfeiting and color-changing materials.Fluorescent probes are widely used in the real-time detection of small molecules due to their advantages of convenient synthesis,simple operation and low cost.Fluorescent probe based on small molecules is a common detection technique,which has the advantages of strong specificity and high spatial and temporal resolution in the detection of active small molecules in cells.In daily life,F^-,H₂S and H₂O₂,as small molecules,are closely related to organisms and play a regulating role in the physiological and pathological processes of organisms.Too high or too low concentration will affect the health of organisms.Based on this,three fluorescence probes were synthesized for specific recognition of F^-,H₂S and H₂O₂respectively.The identification properties of the probe for F^-,H₂S and H₂O₂were studied systematically,and their structures were verified by means of NMR and mass spectrometry.The specific research contents are as follows:1.Three compounds TPICBT,TPICBI and TPICBO with tetraphenylethene and coumarin rings were synthesized by Knoevenagel condensation reaction.The fluorescence of the three compounds was weak in pure THF solution,but the fluorescence intensity was significantly enhanced when the moisture ratio increased to 99%.The AIE properties of the three compounds were further confirmed by DLS and SEM.Among them,TPICBI and TPICBO also have obvious irreversible mechanical grinding discoloration properties.In addition,TPICBT can also be used as a proportional fluorescent probe with both F^-and H₂S response functions.The probe TPICBT has good selectivity and anti-interference when detecting F^-and H₂S,and can quickly and sensitively identify F^-and H₂S.In addition,the TPICBT probe has been successfully used to prepare strip and realize the rapid detection of F^-and H₂S.The probe TPICBT was also used to detect the freshness of food.The results showed that the probe TPICBT could be used to detect H₂S gas emitted from raw food decay.In addition,the probe TPICBT has good cell permeability and low toxicity,and can be used as a fluorescent dye for cell fluorescence imaging.Meanwhile,the detection of exogenous H₂S has also been successfully carried out.2.An open fluorescent probe DNTBA with tetraphenylethene derivatives as fluorophores and 2,4-dinitrophenyl ether as recognition sites was designed and synthesized,which could perform nude eye recognition on H₂S.The fluorescence probe DNTBA has good selectivity and anti-interference performance against H₂S with low detection limit.In addition,the probe DNTBA can be successfully applied to the test strip to detect H₂S.In addition,the intermediate TBA also has a good AIE property.With the increase of the proportion of water,the fluorescence emission intensity also increases.It can be seen that the intermediate TBA has a significant AIE property.3.An AIE fluorescent probe TBIDP was designed and synthesized,which used tetraphene derivatives as fluorescors and aryl borate as recognition sites to achieve naked eye detection of H₂O₂.In the solution of CH₃CN:H₂O=1:4,the fluorescence probe has good selectivity and anti-interference performance against H₂O₂,and the detection limit is low.The probe can also be successfully applied to test strips for convenient and quick detection of H₂O₂.In addition,the intermediate TBD also has a AIE property.With the increase of the proportion of water,the fluorescence emission intensity also increases,and the fluorescence emission intensity reaches the maximum at 80%.It can be seen that the intermediate TBD has a AIE property.