新型香豆素类荧光探针的合成及其对Cu~(2+)的识别性能

以2-羟基-4-甲氧基苯甲醛和丙二酸二乙酯为起始原料,设计并合成了一种新型的Cu~(2+)荧光探针7-甲氧基-2-氧代-N-[2-(苯基氨基)乙基]-2H-色烯-3-甲酰胺(NPC),其结构经~1H NMR,~(13)C NMR,MS(EI)和元素分析表征。并研究了室温下,NPC在乙醇和水的混合溶液中对Cu~(2+)的识别性能。结果表明:NPC对Cu~(2+)表现出荧光猝灭效应,具有对Cu~(2+)的选择性识别性能。     

Highly Sensitive Ratiometric Chemosensor for Selective ′Naked‐Eye′ Nanomolar Detection of Co2+ in Semi‐Aqueous Media

An easy‐to‐prepare chemosensor, (E)‐1‐(phthalazine‐4‐yl)‐2‐(1‐(pyridine‐2‐yl)ethylidene) hydrazine ( 3 ), structurally characterized by single X‐ray crystallography, is developed for the selective and sensitive detection of Co²⁺ in aqueous media. Chemosensor 3 shows both absorption and fluorescence responses to Co²⁺ by forming a 1:1 complex (among the surveyed metal ions) with a detection limit down to 50 nM . It can also be used as a ′naked‐eye′ sensor due to the outstanding visible and emission color changes from yellow to red and blue to orange, respectively.     

A Turn‐On Fluorescent Probe for Highly Selective and Sensitive Detection of Palladium

A novel turn‐on fluorescent probe for the detection of palladium has been designed. The probe can selectively and sensitively detect palladium in solution, and the limit of detection was calculated to be 11.4 nmol·L^?1. Furthermore, the probe was successfully used for fluorescence imaging of palladium in living cells.     

Synthesis of Highly Sensitive Fluorescent Probe Based on Tetrasubstituted Imidazole and Its Application for Selective Detection of Ag+ Ion in Aqueous Media

A small molecule fluorescent probe, 4-[2-(4-chlorophenyl)-4,5-diphenyl-1H-imidazol-1-yl]aniline(L) for detecting Ag⁺ ion was gently synthesized via one-pot multi-component reaction catalyzed by H₃[PW₁₂O₄₀] under solvent-free microwave irradiation. When the concentration of Ag⁺ ion changed from 0 to 8.0×10⁻⁶ mol/L in the solution of H₂O/CH₃OH(19:1, volume ratio), the fluorescence emission spectrum was blue-shifted and accompanied by a gradual increase in fluorescence intensity with a low detection limit of 3.0×10⁻¹¹ mol/L. Moreover, UV-Vis absorption titration experiment demonstrated a 1:1 stoichiometric ratio and an association constant of (9.95±0.44)×10⁵ L/mol between probe L and Ag⁺ ion, and thus their complexation mechanism was also proposed and verified. More importantly, this fluorescent probe was remarkably specific for Ag⁺ ion under the interference of other metal ions and exhibited a wide pH application range of 4.0-8.0. Additionally, preliminary application of this probe was also carried out and satisfactory results were shown.     

A Highly Selective and Sensitive Fluorescent Chemosensor for Detection of Al3+ in Totally Aqueous Media

A fluorescent chemosensor ( 1 ) based on 2‐hydroxy‐1‐naphthaldehyde Schiff‐base was developed for the detection of Al³⁺ in 100% aqueous solution. Upon addition of Al³⁺, a significant fluorescence enhancement was observed, which was not affected by other metal ions including Na⁺, K⁺, Ca²⁺, Mg²⁺, Mn²⁺, Co²⁺, Ni²⁺, Cu²⁺, Cr³⁺, Ag⁺, Pb²⁺, Zn²⁺, Cd²⁺, Hg²⁺, Fe²⁺ and Fe³⁺ under weak acid conditions. Moreover, the specific response to Al³⁺ was visible under natural light. The binding mode between 1 and Al³⁺ was clarified by ESI‐MS and ¹H NMR.     

Selective Chemosensor of Fe3+ Based on Fluorescence Quenching by 2,2′‐Bisbenzimidazole Derivative in Aqueous Media

2,2′‐Bisbenzimidazole derivative ( L ) was designed as a fluorescent chemosensor for Fe³⁺. This structurally simple chemosensor displays significant fluorescence quenching with increasing concentrations of Fe³⁺. L exhibited high selectivity and antidisturbance for Fe³⁺ among environmentally relevant metal ions in aqueous media. The method of Job's plot indicated the formation of 1:2 complex between L and Fe³⁺, and the possible binding mode of the system was also proposed. In addition, further study demonstrates the detection limit on fluorescence response of the sensor to Fe³⁺ is down to 10^?7 mol·L^?1 range. The binding mode was investigated by fluorescence spectra, ESI‐MS, IR data, ¹H NMR, ¹³C NMR and crystal data.     

A Highly K+‐Selective Two‐Photon Fluorescent Probe

A highly K⁺‐selective two‐photon fluorescent probe for the in vitro monitoring of physiological K⁺ levels in the range of 1–100 mM is reported. The two‐photon excited fluorescence (TPEF) probe shows a fluorescence enhancement (FE) by a factor of about three in the presence of 160 mM K⁺, independently of one‐photon (OP, 430 nm) or two‐photon (TP, 860 nm) excitation and comparable K⁺‐induced FEs in the presence of competitive Na⁺ ions. The estimated dissociation constant (K_d) values in Na⁺‐free solutions (K_d^OP=(28±5) mM and K_d^TP=(36±6) mM ) and in combined K⁺/Na⁺ solutions (K_d^OP=(38±8) mM and K_d^TP=(46±25) mM ) reflecting the high K⁺/Na⁺ selectivity of the fluorescent probe. The TP absorption cross‐section (σ_2PA) of the TPEF probe+160 mM K⁺ is 26 GM at 860 nm. Therefore, the TPEF probe is a suitable tool for the in vitro determination of K⁺.     

Highly Sensitive Acidic pH Fluorescent Probe Based on A Boradiaza-indacene Derivative

A pH-sensor with a pKa value of 5.05 based on 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene(BODIPY) dye was synthesized and demonstrated to be highly sensitive within a pH range of 4.0―6.0 and was highly photostable,which makes it a potential pH fluorescent probe.The new pH-sensor will find its application in studying acidic organelles in living cells.     

A Highly Sensitive Quinoline-Containing Rhodamine B Thiohydrazide Based Fluorescent Probe for Hg2+ in Aqueous Solution and Living Cells

Quinoline-appended rhodamine B thiohydrazide based fluorescent probe was designed and applied in fluorescent detections of mercury ions in both aqueous solution and living cells. The signal change of the probe is based on a specific metal ion induced reversible ring-opening mechanism of a rhodamine B thiohydrazide. The probe exhibits a dynamic response concentration range for Hg²⁺ from 1.0 × 10^?8 to 1.0 × 10^?5 M with a detection limit of 8.5 × 10^?9 M. The fluorescent probe is pH independent in medium condition and exhibits high selectivity over other common metal ions.     

纯水中检测汞离子与银离子的菲啰啉类荧光探针

合成了菲啰啉类化合物探针1,并通过核磁共振波谱(NMR)、质谱(MS)、红外光谱(IR)对其结构进行了表征。利用荧光发射光谱考察了探针1对Hg~(2+)及Ag~+的识别性能。结果表明,探针1在纯水介质中以荧光猝灭的方式识别Hg~(2+)和Ag~+,其结合比分别为1∶1和2∶1,检测的线性范围分别为9.0×10~(-7)～1.1×10~(-5)和8.0×10~(-7)～7.0×10~(-6) mol/L,相关系数(r~2)均大于0.99,检出限均低至10~(-8)mol/L。根据探针1识别前后荧光强度的剧烈变化,建立了裸眼检测Hg~(2+)和Ag~+的可视化分析方法。通过等温量热滴定与~1H NMR滴定考察了识别过程的热力学参数和作用机理。该研究对生物体及环境领域中Hg~(2+)和Ag~+的实时监测具有潜在的应用价值。     

A Pyrene Derivative for Hg2+‐Selective Fluorescent Sensing and Its Application in In Vivo Imaging

An Hg²⁺‐selective fluorescent sensor ( 1 ) bearing pyrene as a fluorophore was synthesized. A sandwich‐stacking binding mode was formed during the binding process, which increased the excimer fluorescence 22‐fold at 490 nm. Compound 1 was successfully applied in in vivo imaging to trace the enrichment and distribution of mercury in the nervous system, digestive system, and reproductive system of Caenorhabditis elegans, as well as the organs of zebrafish.     

一种基于喹唑啉酮衍生物的荧光探针对次氯酸根离子的识别

次氯酸根(ClO~-)在人体免疫系统中发挥着重要的作用,其识别与检测备受关注。本文设计合成了一种含有喹唑啉酮骨架的腙型荧光探针(HEMQ),并通过~1H NMR、~(13)C NMR、高分辨质谱(HRMS)表征了其结构。探针HEMQ在V(乙醇)∶V(水)=1∶1(c(PBS)=0.02 mol/L,pH=8.7)溶液中对ClO~-具有良好的选择性且响应快速,荧光发生显著猝灭。探针HEMQ对ClO~-具有较高的灵敏度,检测限为1.0×10-4mol/L。此外,ClO~-可引起探针溶液由黄色到无色的颜色变化,因此HEMQ可作为比色、荧光双通道响应的ClO~-探针。     

新型香豆素类探针的合成及其高灵敏性和高选择性对纯水中Pd2+的荧光和比色检测

我们设计并合成了一种新型香豆素类Pd2+荧光探针（化合物1）。化合物1由香豆素和羧甲基羟胺组成,其能实现纯水中Pd2+的高选择性和高灵敏性检测,且检测限低至4.0 × 10-8 mol/L。此外,该探针能在pH为4~9的范围内有效检测Pd2+。     

基于1,8-萘酰亚胺与罗丹明B间荧光共振能量转移的高选择性Hg2+比率荧光探针

以罗丹明B与1,8-萘二甲酰亚胺反应合成了1个高选择性Hg²⁺比率荧光探针(RN). 在甲醇/乙腈/4-羟基哌嗪乙磺酸缓冲溶液(pH=7.2, 体积比8:1:1)中, RN对Hg²⁺具有比色和比率荧光双重响应. 加入Hg²⁺后, RN的紫外-可见光谱在约556 nm处产生强吸收, 溶液由浅绿色变为橙色, 其它金属离子对RN的紫外-可见光谱几乎无影响. 无Hg²⁺存在时, RN的荧光光谱在540 nm处出现萘二甲酰亚胺荧光团的特征峰; 加入Hg²⁺后, 540 nm处的发射带逐渐消失, 同时在580 nm附近产生强荧光, 荧光颜色从绿色变为橙色. 这归因于从萘酰亚胺到开环罗丹明B的荧光共振能量转移(FRET), 探针RN对Hg²⁺的比率荧光响应具有高选择性, 不受其它共存金属离子的干扰.     

基于四丹磺酰胺杯[4]芳烃的汞离子荧光化学传感器

我们方便地合成了上沿修饰四丹磺酰胺基团的杯[4]芳烃衍生物1,发现该化合物在含50％水的乙腈中显示出对汞离子高选择性和灵敏性的识别作用,竞争实验表明多数金属离子对其检测干扰较小。机理研究结果表明荧光萃灭源于由丹磺酰胺基团到汞离子的光致电子转移过程。另外,通过研究1和1-Hg2+的荧光衰减实验,以及对比双丹磺酰胺杯[4]芳烃2和单丹磺酰胺杯[4]芳烃3对汞离子的识别作用,发现化合物1的四丹磺酰胺基团具有很好的预组织和协同作用。化合物1对汞离子的检测限为3.41×10-6 mol·L-1,这可以使1成为一个潜在的汞离子荧光化学传感器。     

基于牛血清白蛋白功能化金纳米棒的荧光探针测定Hg2+

建立了一种以牛血清白蛋白功能化的金纳米棒(BSA-Cys-GNRs)为荧光探针检测Hg²⁺的新方法。以半胱氨酸作为连接臂成功将牛血清白蛋白修饰在金纳米棒表面,通过紫外可见吸收光谱、荧光光谱、红外光谱和荧光倒置显微镜等多种分析方法对材料进行表征。研究发现,在295nm波长光激发下,BSA-Cys-GNRs探针在338nm显示强荧光,而Hg²⁺能够有效地猝灭BSA-Cys-GNRs的荧光。对一系列影响猝灭效果的因素进行考察,得出pH 4.0、孵育时间5.0min为最佳检测条件。Mn²⁺、K⁺、Ni²⁺、Na⁺、Cr³⁺、Cd²⁺、Mg²⁺、Cu²⁺、Ca²⁺、Al³⁺和Zn²⁺对BSA-Cys-GNRs的荧光信号没有明显的影响。当Hg²⁺的浓度为0.04444~8.888μmol·L^-1时,荧光猝灭效率与Hg²⁺的浓度之间存在良好的线性关系,检测限为8.08nmol·L^-1。将该方法用于环境水样中Hg²⁺的检测,回收率为98.9%~105.0%。     

一种可再生高选择性的硫化氢荧光探针

为了方便地检测环境样品中的硫化氢,利用香豆素酰肼肟配体构建了一个基于其铜配合物的可再生高选择性的硫化氢荧光探针(1-Cu²⁺)。 顺磁性Cu²⁺的荧光猝灭作用使探针的荧光很弱。 Na₂S溶液的加入可显著增强其荧光,其它常见阴离子(F^-,Cl^-,Br^-,I^-,CO32-,HPO42-,H₂PO4-,NO2-,NO3-,SO42-,CH₃COO^-,N3-,S₂O32-,CN^-)对配合物探针的荧光影响很小,共存时也不会干扰探针对硫化氢的增强响应。 Cu²⁺的加入能够再生探针(1-Cu²⁺),通过依次加入Cu²⁺和S^2- ,可重复地检测S^2-。 该探针响应时间快(~5 s),在0.5~5.0 μmol/L的范围内对H₂S响应呈线性,检测限低至37 nmol/L。     

A Highly Selective Turn-On Fluorescent Probe for the Detection of Zinc

A novel turn-on fluorescence probe L has been designed that exhibits high selectivity and sensitivity with a detection limit of 9.53 × 10⁻⁸ mol/L for the quantification of Zn²⁺. ¹H-NMR spectroscopy and single crystal X-ray diffraction analysis revealed the unsymmetrical nature of the structure of the Schiff base probe L. An emission titration experiment in the presence of different molar fractions of Zn²⁺ was used to perform a Job’s plot analysis. The results showed that the stoichiometric ratio of the complex formed by L and Zn²⁺ was 1:1. Moreover, the molecular structure of the mononuclear Cu complex reveals one ligand L coordinates with one Cu atom in the asymmetric unit. On adding CuCl₂ to the ZnCl₂/L system, a Cu-Zn complex was formed and a strong quenching behavior was observed, which inferred that the Cu²⁺ displaced Zn²⁺ to coordinate with the imine nitrogen atoms and hydroxyl oxygen atoms of probe L.     

A Highly Selective and Sensitive Ratiometric Fluorescent Probe for Hypochlorite and Its Application

A novel water-soluble hybrid fluorescein-coumarin dye(FLNC) fluorescence ratiometric probe to recognize OCl^- was designed and synthesized. The most prominent feature of the probe is that the molecular structure contains two different fluorophores, and the fluorescein moiety was connected to coumarin moiety by diacylhydrazine linker. When OCl^- was added, the two fluorophores in the FLNC probe could have a rapid respond simultaneously, with high selectivity and sensitivity towards OCl^- among other reactive oxygen species/reactive nitrogen species(ROS/RNS) and anions, and the detection limit was measured to be 0.30 μmol/L. In addition, the color changes of the solution could be observed by the naked eye and have a short response time(completed within 1 min), which suggestes that the probe FLNC has the potential to be used for real-time detection.     

A New Fluorescent Probe for Selective Cd2+ Detection and Cell Imaging

A new highly selective fluorescent probe, (E)‐4‐(4‐([2,2′:6′,2′′‐terpyridin]‐4′‐yl)styryl)‐1‐octadecylpyridin‐1‐ium bromide (ZC‐F8), was designed and synthesized for cadmium detection and cell imaging. The fluorescence spectra of ZC‐F8 exhibited its excellent response towards Cd²⁺ via intramolecular charge transfer effect and aggregation induced emission effect. The cell‐imaging experiment was carried out to estimate the actual biological application of ZC‐F8. The probe displayed ideal membrane permeable and labeled property for cadmium, indicating its promising application for metal ions detection and tracing in living cells.