Synthesis And Ion Recongnition Of Reactive Fluorescence Probes Based On Benzothiazole

Benzothiazole derivatives are important kinds of nitrogen containing heterocyclic compounds,they have been widely used in the fields of biological sciences and medical sciences.And these compounds have excellent fluorescence properties.Therefore,in recent years,more and more attention has been devoted to these compounds with the application in fluorescent probes.We designed and synthesized a series of fluorescent sensors based on benzothiazole-derived,and got some meaningful results.The details are as follows:1.A new benzothiazole-derived fluorescence probe 2-?4-azidobenzyl?oxy-3-?benzo[d]thiazzol-2-yl?-5-methylbenzaldehyde?HBTA?was synthesized from 3-?benzo[d]thiazol-2-yl?-2-hydroxy-5-methylbenzaldehyde,and the structure of HBTA was characterized.The recognition behaviors of HBTA to H₂ S were investigated and the results show that HBTA exhibits good selectivity and sensitivity to H₂ S with fast response and good anti-interference ability.The probe can be applied to detect H₂ S in a broad pH range,and the detection limit of HBTA for H₂ S was estimated to be 9.09×10^-7 M.Cell imaging studies reveal that HBTA is capable of detect H₂ S in live cells.2.A new benzothiazole-derived fluorescence probe 3-?benzo[d]thiazol-2-yl?-5-methyl-2-?prop-2-yn-1-yloxy?benzaldehyde?BBT?was synthesized from 3-?benzo[d]thiazol-2-yl?-2-hydroxy-5-methylbenzaldehyde with 3-bromopropyne as a hydroxy protecting group,and the structure of BBT was characterized.The recognition behaviors of BBT to Pd²⁺ were investigated and the results show that BBT exhibits good selectivity,sensitivity and good anti-interference ability to Pd²⁺,and the detection limit of BBT for Pd²⁺ was estimated to be 1.41×10^-4 M.Besides,test paper experiments show that BBT have potentially application value in various water samples.3.A new reactive probe,1-?benzo[d]thiazol-2-yl?naphthalen-2-yl-picolinate?BTNP?,was designed and synthesized from 1-?benzo[d]thiazol-2-yl?naphthalen-2-ol with picolinic acid as a hydroxy protecting group.BTNP acts as a highly selective probe to Cu²⁺ in DMSO/H₂O?7/3,v/v,Tris-HCl 10 m M,pH =7.4?solution based on Cu²⁺ catalyzed hydrolysis of the picolinate ester moiety in BTNP,which leads to the formation of an ESIPT active product with dual wavelength emission enhancement.The probe also possesses the advantages of simple synthesis,rapid response and high sensitivity.The pseudo-first-order reaction rate constant was calculated to be 0.205 min-1,and the detection limit of BTNP for Cu²⁺ was estimated to be 1.34×10^-6 M.Moreover,application of BTNP to Cu²⁺ detection in living cells and real water samples were also explored.4.A fluorescent probe?E?-2-?3-?benzo[d]thiazol-2-yl?-2-hydroxy-5-methylstyryl?-3-methylbenzo[d]thiazol-3-ium iodide?DBT?based on conjugation of 2,3-dimethylbenzo[d]thiazol-3-ium iodide to 3-?benzo[d]thiazol-2-yl?-2-hydroxy-5-methylbenzaldehyde for the detection of sulfur dioxide derivatives?HSO₃^-/SO32-?has been developed.DBT exhibits highly selective colorimetric and ratiometric fluorescence dual response to HSO₃^-with a fluorescence detection limit of 3.50×10^-7 M.The HSO₃^-sensing mechanism was confirmed to undergo nucleophilic addition of HSO₃^-to alkene double bond of DBT as evidenced by 1H NMR and HRMS analysis.The probe is MCF-7 cell permeable and applicable for fluorescence imaging of exogenous and intrinsically generated intracellular SO₂ derivatives in the living cells.Fluorescence co-localization studies reveal that DBT is a mitochondria-targetable fluorescent probe.Thus,DBT has potential application for exploring the role played by SO₂ derivatives in biology.