香豆素类肼荧光探针的合成及应用

以4-三氟甲基-7-羟基香豆素为荧光母体,4-溴丁酰基为识别基团,合成了一种基于分子内电荷转移机制的肼荧光探针XS-1,其结构经核磁共振氢谱(¹H NMR),核磁共振碳谱(¹³C NMR)和高分辨质谱(HRMS)确证,通过荧光发射光谱研究了探针对肼的响应性能。结果表明,在磷酸盐缓冲液(10 mmol,pH7.4)中,探针XS-1能通过荧光增强作用识别肼,并具有很好的选择性和抗干扰能力,检出限为0.11μmol/L。探针XS-1具有斯托克斯位移大(144 nm)、线性范围宽(0～400μmol/L)、合成简便以及能在水相中检测肼等优点,并已成功用于实际水样中肼的定量检测。     

新型香豆素类Zn~(2+)荧光探针的合成及细胞成像研究

设计、合成了一种光诱导电子转移(Photoinduced Electron Transfer,PET)型香豆素类水溶性Zn~(2+)荧光探针1和2.通过荧光光谱分析实验发现,该探针具有较好的选择性和灵敏度,其荧光强度随着Zn~(2+)的浓度增大而逐渐增强,并可成功实现对人乳腺癌细胞(MCF-7)和枯草杆菌(B.subtilis)的标记.目标探针分子结构均经1H NMR,13C NMR,IR,HRMS及X单晶射线衍射进行了表征,并且还获得了探针2与Zn~(2+)络合物[Zn(2)]的单晶结构,X单晶衍射实验表明络合物[Zn(2)]中Zn~(2+)为五配位,其几何构型为双锥体.     

一种香豆素类锌离子荧光探针的合成及性能

通过Pechmann法使间苯二酚和乙酰乙酸乙酯发生脱水缩合反应,合成了4-甲基-7-羟基香豆素,再与六次甲基四胺反应,生成7-羟基-4-甲基-8-甲酰基香豆素,最终与吲哚酰肼发生席夫碱反应合成一种香豆素类荧光探针L。通过核磁共振波谱仪(NMR)、质谱(MS)、傅里叶变换红外光谱仪(FTIR)、荧光发射光谱仪和紫外可见分光光度计等技术手段研究该探针L的结构及其荧光性能。结果表明,探针L与Zn~(2+)的配合比为1∶1,对Zn~(2+)的检测限达到3.6×10~(-8)mol/L,降低了对Zn~(2+)的检测浓度,同时探针L对锌离子具有高选择性,可应用于在生物体内Zn~(2+)的检测。     

萘异硫氰酸酯修饰的水杨醛衍生物作为氟离子荧光探针的研究

以萘异硫氰酸酯分别化学修饰水杨醛、4-(二乙氨基)水杨醛,合成了两种荧光分子(分子1和2),利用核磁共振和高分辨质谱技术对其结构进行了表征和确证.采用荧光光谱技术对这两种分子与常见阴离子的结合进行研究,结果表明,分子1和分子2均可选择性识别F–,可作为检测F–的荧光探针.探针1(分子1)对F–表现出荧光增强型响应,当F...     

基于香豆素荧光团的新型极性检测荧光探针的开发及其成像应用

极性是生物微环境的重要参数之一, 在很大程度上, 生物体内许多生命活动都受到极性变化的影响, 本工作通过改变香豆素母体上的推-拉电子基团, 设计并合成了一种具有较大斯托克斯位移的新型极性荧光探针COM-PO, 该探针的荧光强度和波长会随着测试体系的极性变化而发生改变. 当极性增加时, COM-PO的激发态能量会通过偶极-偶极的相互作用散失在溶剂中, 荧光发射强度降低, 而在低极性溶剂中荧光发射强度增强, 利用这种特性实现了对极性的检测. 本工作通过荧光光谱、荧光成像实验表明COM-PO能够在样品中实现极性检测, 该探针有望实现与极性相关的疾病的早期诊断.     

基于香豆素-肟的次氯酸根探针的设计、合成及荧光成像应用

通过将香豆素的2-位内酯转化为肟基,设计、合成了一种用于基于香豆素-肟类的次氯酸根荧光探针Cou-HC.Cou-HC不仅对次氯酸根表现出快速和高选择性响应的特点,而且探针氧化后的产物不会与生物硫醇等发生反应,从而可以避免生物硫醇对于次氯酸根响应的干扰.细胞成像实验结果表明,探针可以对RAW 264.7细胞中内源性和外源...     

基于香豆素343的荧光探针快速检测亚硫酸根

以香豆素343和2-苯并噻唑乙腈为原料,合成了香豆素343-亚硫酸根离子探针(Coumarin 343-SO₂),并用¹H NMR、¹³C NMR、MS和HRMS等技术手段对合成的化合物进行了表征。 该探针与亚硫酸根离子(SO₃^2-)发生亲核加成反应后,阻断了苯并噻唑与香豆素的共轭结构,从而引起荧光强度的变化,达到检测亚硫酸根离子的目的。 此探针对SO₃^2-具有响应快、高灵敏度、高选择性及检测限低至0.08 μmol/L的特点,其它常见的阴离子及还原性物质对SO₃^2-的检测均无干扰。 此外,该探针具有良好的细胞膜通透性,可用于活细胞中对SO₃^2-进行荧光成像。     

基于香豆素的荧光探针的合成及其对硫离子的识别性能

以4-甲基-7-羟基香豆素为荧光团、 2,4-二硝基苯磺酸酯为识别位点,合成了荧光探针L,并通过核磁共振波谱(HNM)和元素分析对其结构进行表征。探针L对S^2-的识别具有单一选择性和良好的抗干扰性,且呈现明显的荧光增强效应。探针L测定S^2-的检出限为0.319μmol/L。通过核磁氢谱、荧光滴定及等摩尔滴定法确证了探针L对S^2-的识别机理。     

香豆素类阴离子荧光探针的研究进展

香豆素是一种重要的天然产物,同时具有优良的生物活性和光学活性.阴离子广泛存在于生命体和自然环境中,对人类的生活有着巨大的影响,因此开发能够特异性检测某种阴离子的荧光探针具有非常重要的科学意义.主要总结了近几年香豆素类阴离子荧光探针的研究进展,重点讨论了检测F-、ClO-、ONOO-以及一些其他阴离子的香豆素类荧光探针的...     

一种快速响应的线粒体靶向荧光探针用于检测活细胞和斑马鱼中的次氯酸盐

以香豆素为荧光团,设计并合成了一种线粒体靶向荧光探针Cou-Py,用于检测ClO^-。由于肟基在激发态的C=N异构化,Cou-Py表现出非常微弱的荧光,能够实现ClO^-促发的脱氧反应,在5 s内实现荧光恢复。此外,Cou-Py对ClO^-表现出高的选择性和低的检测限（6.87 nmol·L^-1）。重要的是,Cou-Py已成功用于检测MCF-7细胞线粒体和斑马鱼幼虫中的ClO^-。     

A Naphthalimide-Based Fluorescent Probe for the Detection and Imaging of Mercury Ions in Living Cells

The selective and efficient monitoring of mercury (Hg²⁺) contamination found in the environment and ecosystem has been carried out. Thus, a new 1,8-naphthalimide-based fluorescent probe NADP for the detection of Hg²⁺ based on a fluorescence enhancement strategy has been designed and synthesized. The NADP probe can detect Hg²⁺ with high selectivity and sensitivity and a low detection limit of 13 nm . The detection mechanism was based on a Hg²⁺-triggered deprotection reaction, resulting in a dramatic change in fluorescence from colorless to green at physiological pH. Most importantly, biological investigation has shown that the NADP probe can be successfully applied to the monitoring of Hg²⁺ in living cells and zebrafish with low cytotoxicity.     

Quinolinium‐Based Fluorescent Probes for the Detection of Thiophenols in Environmental Samples and Living Cells

A new type of fluorescent probes for thiophenols, 6HQM‐DNP and 7HQM‐DNP, containing 6‐ or 7‐hydroxy quinonlinium as fluorophore and 2,4‐dinitrophenoxy (DNP) as nucleophilic recognition unit were constructed. As ethers, these non‐fluorescent probe molecules can release the corresponding fluorescent quinolinium (6HQM and 7HQM) through aromatic nucleophilic substitution (S_NAr) by thiolate anions from thiophenols. The sensing reaction is highly sensitive (detection limit of 8 nM for 7HQM‐DNP) and highly selective to thiophenols over aliphatic thiols and other nucleophiles under neutral conditions (pH 7.3). The probes respond rapidly to thiophenols, with second‐order rate constants k=45 M ^?1 s^?1 for 7HQM‐DNP and 24 M ^?1 s^?1 for 6HQM‐DNP. Furthermore, the selective detection of thiophenols in living cells by 7HQM‐DNP was demonstrated by confocal fluorescence imaging. In addition, these quinolinium salts show excellent chemical and thermal stability. In conclusion, this type of probes may find use in the detection of thiophenols in environmental samples and biosystems.     

在纯水体系和活细胞中高选择检测Fe3+的香豆素荧光探针

设计、合成了一种香豆素类荧光探针CF470,该探针通过引入高水溶性且选择性与Fe~(3+)配位的多羟基基团实现了纯水体系中Fe~(3+)的检测。当在探针体系中加入Fe~(3+)后,其强烈的蓝色荧光在2 min内就可被完全猝灭。探针不仅对Fe~(3+)快速、高选择响应,而且由于引入了亲水的多羟基基团具有良好的水溶性。更重要的是,探针对活细胞低毒、生物相容性好,被成功应用于活细胞中Fe~(3+)的成像。     

以香豆素为母体快速检测内源性甲醛的荧光探针

基于甲醛(FA)与肼易发生亲核加成反应,从而阻断肼与荧光母体间电子传递的光诱导电荷转移(PET)机理,设计合成了以香豆素为母体的甲醛荧光探针3-苯并噻唑-7-肼香豆素(Coun)。 实验结果显示,Coun与FA的最佳反应时间为4 min,极大地提高了检测效率,检测限为5×10^-6 μmol/L。 该探针具有良好的细胞膜通透性,可应用于生物领域,检测细胞内的甲醛含量。     

Fluorescent Probes Based on Charge and Proton Transfer for Probing Biomolecular Environment

Fluorescent probes for sensing fundamental properties of biomolecular environment, such as polarity and hydration, help to study assembly of lipids into biomembranes, sensing interactions of biomolecules and imaging physiological state of the cells. Here, we summarize major efforts in the development of probes based on two photophysical mechanisms: (i) an excited-state intramolecular charge transfer (ICT), which is represented by fluorescent solvatochromic dyes that shift their emission band maximum as a function of environment polarity and hydration; (ii) excited-state intramolecular proton transfer (ESIPT), with particular focus on 5-membered cyclic systems, represented by 3-hydroxyflavones, because they exhibit dual emission sensitive to the environment. For both ICT and ESIPT dyes, the design of the probes and their biological applications are summarized. Thus, dyes bearing amphiphilic anchors target lipid membranes and report their lipid organization, while targeting ligands direct them to specific organelles for sensing their local environment. The labels, amino acid and nucleic acid analogues inserted into biomolecules enable monitoring their interactions with membranes, proteins and nucleic acids. While ICT probes are relatively simple and robust environment-sensitive probes, ESIPT probes feature high information content due their dual emission. They constitute a powerful toolbox for addressing multitude of biological questions.     

A Two-Photon Fluorescent Probe for the Visual Detection of Peroxynitrite in Living Cells and Zebrafish

Peroxynitrite (ONOO⁻), as an important reactive oxygen species (ROS), holds great potential to react with a variety of biologically active substances, leading to the occurrence of various diseases such as cancer and neurodegenerative diseases. In this work, we developed a novel mitochondria-localized fluorescent probe, HDBT-ONOO⁻, which was designed as a mitochondria-targeting two-photon fluorescence probe based on 1,8-naphthylimide fluorophore and the reactive group of 4-(bromomethyl)-benzene boronic acid pinacol ester. More importantly, the probe exhibited good biocompatibility, sensitivity, and selectivity, enabling its successful application in imaging the generation of intracellular and extracellular ONOO⁻. Furthermore, exogenous and endogenous ONOO⁻ products in live zebrafish were visualized. It is greatly expected that the designed probe can serve as a useful imaging tool for clarifying the distribution and pathophysiological functions of ONOO⁻ in cells and zebrafish.     

A PEGylated Fluorescent Turn‐On Sensor for Detecting Fluoride Ions in Totally Aqueous Media and Its Imaging in Live Cells

Owing to the considerable significance of fluoride anions for health and environmental issues, it is of great importance to develop methods that can rapidly, sensitively and selectively detect the fluoride anion in aqueous media and biological samples. Herein, we demonstrate a robust fluorescent turn‐on sensor for detecting the fluoride ion in a totally aqueous solution. In this study, a biocompatible hydrophilic polymer poly(ethylene glycol) (PEG) is incorporated into the sensing system to ensure water solubility and to enhance biocompatibility. tert‐Butyldiphenylsilyl (TBDPS) groups were then covalently introduced onto the fluorescein moiety, which effectively quenched the fluorescence of the sensor. Upon addition of fluoride ion, the selective fluoride‐mediated cleavage of the Si? O bond leads to the recovery of the fluorescein moiety, resulting in a dramatic increase in fluorescence intensity under visible light excitation. The sensor is responsive and highly selective for the fluoride anion over other common anions; it also exhibits a very low detection limit of 19 ppb. In addition, this sensor is operative in some real samples such as running water, urine, and serum and can accurately detect fluoride ions in these samples. The cytotoxicity of the sensor was determined to be Grade I toxicity according to United States Pharmacopoeia and ISO 10993‐5, suggesting the very low cytotoxicity of the sensor. Moreover, it was found that the senor could be readily internalized by both HeLa and L929 cells and the sensor could be utilized to track fluoride level changes inside the cells.     

镁离子荧光探针

镁离子（Mg²⁺）在许多生理过程中扮演着重要的角色,因此对镁离子的选择性识别引起了人们极大的关注。本文综述了近年来镁离子荧光探针的最新研究进展。镁离子荧光探针体系主要分为：喹啉类、β-二酮类、冠醚/多醚类、羧酸类、荧光素/罗丹明类、配合物类、聚合物类和纳米材料类等。本文列举了每类探针分子代表性的化合物并总结比较了不同类型的镁离子荧光探针体系。     

Two‐Photon Fluorescent Probes for Metal Ions

Two‐photon microscopy (TPM) has become an indispensible tool in biology and medicine owing to the capability of imaging the intact tissue for a long period of time. To make it a versatile tool in biology, a variety of two‐photon probes for specific applications are needed. In this context, many research groups are developing two‐photon probes for various applications. In this Focus Review, we summarize recent results on model studies and selected examples of two‐photon probes that can detect intracellular free metal ions in live cells and tissues to provide a guideline for the design of useful two‐photon probes for various in vivo imaging applications.