Abstract：
A novel ratiometric fluorescent probe, namely 5-[(3-dicyanoylidene -5.5-dimethyl) cyclohexenyl-1-ethenyl] salicylaldehyde-3\'-hydroxybenzohydrazone (DCSH) is presented for the selective sensing of Zn2+ ion in acetonitrile/water (2/3, pH 7.4) solution. Introducing Zn2+ ions notably caused the peak emission of DCSH to shift from 560 nm to 646 nm, accompanied with a significant enhancement of its intensity. A vivid change in fluorescence color from yellow to red facilitated the immediate identification of Zn2+ ions by visual observation. DCSH exhibits substantial Stokes shifts (110 and 196 nm), rapid detection capability (within 10 s) and high sensitivity to Zn2+ ions, achieving a limit of detection of 31.2 nM. The response mechanism is supposed to involve the block of C = N bond isomerization and excited state intramolecular proton transfer (ESIPT) along with the enhancement of fluorescence through chelation (CHEF) effect. DCSH was effectively utilized for ratiometric fluorescence imaging to monitor exogenous Zn2+ concentrations in HeLa cells. Significantly, DCSH is capable of monitoring elevated levels of Zn2+ ion during apoptosis induced by L-Buthionine sulfoximine (BSO).
摘要：
一种新型比例荧光探针,即5-[（3-二亚苯基-5.5-二甲基）环己烯基-1-乙烯基]水杨醛-3'-羟基苯甲酰腙（DCSH）被提出用于在乙腈/水（2/3，pH7.4）溶液中选择感测Zn2离子。引入Zn2+离子显著导致DCSH的峰值发射从560nm移动到646nm,伴随着其强度的显着增强。荧光颜色从黄色到红色的生动变化有助于通过视觉观察立即鉴定Zn2离子。DCSH表现出大量的斯托克斯位移（110和196nm），快速检测能力（10s内）和对Zn2+离子的高灵敏度，达到31.2nM的检测限。响应机制被认为涉及C=N键异构化和激发态分子内质子转移（ESIPT）的阻断以及通过螯合（CHEF）效应增强荧光。DCSH有效地用于比率荧光成像以监测HeLa细胞中的外源Zn2浓度。重要的是,DCSH能够监测由L-丁硫氨酸亚砜胺（BSO）诱导的细胞凋亡过程中Zn2离子水平的升高。
