充分利用四苯基乙烯化合物2-羟基-5-(1,2,2-三苯基乙烯基)苯甲醛(OHC-TPE-OH)中的活泼羟基和醛基,通过缩合和亲核取代反应设计合成了基于碳氮双键和苯硼酸酯基为ONOO^-识别位点的荧光探针NC-TPE-BOH,并利用光谱法研究探针NC-TPE-BOH的光学性能。结果表明,探针NC-TPE-BOH的DMSO/H₂O(25 μmol/L,体积比1/4,PBS,pH=7.4)测试体系中,当ONOO^-存在时,在530 nm处引起了"turn-off"荧光效应,荧光猝灭比为98.1%,实现了对ONOO^-的特异选择性识别,检出限为4.34×10^-7 mol/L,并且Stokes位移高达195 nm。通过¹HNMR、ESI-MS探究了探针NC-TPE-BOH对ONOO^-的识别原理,探针在ONOO^-存在下,在引起CN键的氧化水解生成羧酸时苯硼酸基也发生了氧化水解,并通过电子转移失去醌酮得氧负离子。

NC-TPE-BOH fluorescence probe with CN bond and phenylboronic ester group as ONOO^- recognition sites is designed and synthesized through condensation and nucleophilic substitution reactions by taking full advantage of the active hydroxyl and aldehyde groups in tetraphenylethylene fluorescent parent 2-hydroxy-5-(1,2,2-triphenylethenyl)benzaldehyde (OHC-TPE-OH).Results show that NC-TPE-BOH probe induces a "turn-off" fluorescence effect at 530 nm in the presence of ONOO^- in DMSO/H₂O (25 μmol·L^-1,v/v=1/4,PBS,pH=7.4) test system,showing a fluorescence quenching ratio of 98.1%.The probe realizes the specific and selective recognition to ONOO^-,with a detection limit of 4.34×10^-7 mol·L^-1,and Stokes shift is as high as 195 nm.The recognition principle of NC-TPE-BOH probe to ONOO^- is investigated by means of 1H-NMR and ESI-MS.It is verified that phenylboronic ester group also experiences oxidative hydrolysis while NC-TPE-BOH probe induces oxidative hydrolysis of -CN to form -COOH in the presence of ONOO^-.Phenylboronic acid group loses quinone to generate oxygen negative ions through electron rearrangement.

李富卓(1998-),男,硕士生