In this work, we synthesized a series of boronate ester fluorescence probes ( E )‐4,4,5,5‐tetramethyl‐2‐(4‐styrylphenyl)‐1,3,2‐dioxaborolane ( STBPin) , ( E )‐ N , N ‐dimethyl‐4‐(4‐(4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolan‐2‐yl)styryl)aniline ( DSTBPin) , ( E )‐4‐(4‐(4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolan‐2‐yl)styryl)benzonitrile ( CSTBPin) , ( E )‐2‐(4‐(4‐methoxystyryl)phenyl)‐4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolane ( MSTBPin) , ( E )‐ N , N ‐dimethyl‐4‐(4‐(4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolan‐2‐yl)styryl)naphthalen‐1‐amine ( NDSTBPin ), and N , N ‐dimethyl‐4‐(2‐(4‐(4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolan‐2‐yl)phenyl)oxazol‐5‐yl)aniline ( DAPOX‐BPin ) for the detection of hydrogen peroxide (H 2 O 2 ). DSTBPin and MSTBPin displayed an “Off–On” fluorescence response towards H 2 O 2 , owing to the loss of the intramolecular charge transfer (ICT) excited state. Whereas, CSTBPin displayed a decrease in fluorescence intensity in the presence of H 2 O 2 owing to the introduction of an ICT excited state. STBPin , on the other hand, produced a small fluorescence decrease, indicating the importance of an electron‐withdrawing or electron‐donating group in these systems. Unfortunately, the longer wavelength probe, NDSTBPin , displayed a decrease in fluorescence intensity. Oxazole‐based probe DAPOX‐BPin produced a “turn‐on” response. Regrettably, DAPOX‐BPin required large concentrations of H 2 O 2 (3?m m ) to produce noticeable changes in fluorescence intensity and, therefore, no change in fluorescence was observed in the cell imaging experiments. Laying the foundations : Boronate stilbene and oxazole fluorescent probes are synthesized and are shown to demonstrate a reasonable fluorescence response towards H 2 O 2 . N , N ‐Dimethyl‐4‐(2‐(4‐(4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolan‐2‐yl)phenyl)oxazol‐5‐yl)aniline ( DAPOX‐BPin ) ( λ ex =350?nm/ λ em =455)?nm produces a fluorescence “turn‐on” response towards H 2 O 2 with a limit of detection of approximately 3?m m .
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机译：在这项工作中，我们合成了一系列硼酸酯荧光探针（E）‐4,4,4,5,5-‐四甲基-2-（4-苯乙烯基苯基）‐1,3,2-‐二氧杂硼烷（STBPin），{E）‐ N，N-二甲基-4-（4-（4,4,5,5-四甲基-1,3,2-二氧杂硼硼烷-2-基）苯乙烯基）苯胺（DSTBPin），（E）-4-（4- （4,4,5,5-四甲基-1,3,2-二氧杂硼硼烷-2-基）苯乙烯基）苄腈（CSTBPin），（E）-2-（4-（4-甲氧基苯乙烯基）苯基）-4,4 ，5,5-四甲基-1,3,2-二氧杂硼烷（MSTPBPin），（E）-N，N-二甲基-4-（4-（4,4,5,5-四甲基-1,3,2-二氧杂硼硼烷-2-基）苯乙烯基萘-1-胺（NDSTBPin）和N，N-二甲基-4-（2-（4-（4,4,5,5-四甲基-1,3,2-二氧杂硼硼烷） -2-基）苯基）恶唑-5基）苯胺（DAPOX-BPin）用于检测过氧化氢（H 2 O 2）。由于分子内电荷转移（ICT）激发态的丧失，DSTBPin和MSTBPin对H 2 O 2表现出“ Off-On”荧光响应。然而，由于引入了ICT激发态，在H 2 O 2存在下，CSTBPin显示出荧光强度的降低。另一方面，STBPin产生的荧光减弱很小，表明这些系统中吸电子或供电子基团的重要性。不幸的是，更长波长的探针NDSTBPin显示出荧光强度的降低。基于恶唑的探针DAPOX-BPin产生“开启”响应。遗憾的是，DAPOX-BPin需要高浓度的H 2 O 2（> 3？m m）才能产生明显的荧光强度变化，因此在细胞成像实验中未观察到荧光变化。奠定基础：合成了硼酸二苯乙烯和恶唑荧光探针，并显示出对H 2 O 2的合理荧光响应。 N，N-二甲基-4-（2-（4-（4,4,5,5-四甲基-1,3,2-二氧杂硼硼烷-2-基）苯基）恶唑-5-基）苯胺（DAPOX-BPin ）（λex = 350？nm /λem = 455）？nm产生针对H 2 O 2的荧光“开启”响应，检出限约为3？mm。
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