罗丹明类钯离子荧光分子探针

将烯丙基结构引入到罗丹明螺环中, 合成了荧光增强型钯离子探针RPd4. RPd4表现出对Pd²⁺的专一选择性和对其它阳离子良好的抗干扰能力. 探针荧光强度随着Pd²⁺的加入逐渐增强, 并且在微摩尔级呈现良好的线性关系, 通过拟合计算得到对Pd²⁺的检出限为0.51 μmol/L. RPd4具有较低的pK_a值(3.81±0.02), 说明该探针可以在近中性pH范围内对Pd²⁺进行选择性识别. 该探针还可以提供比色及荧光两种方式对Pd²⁺进行可视化检测.     

罗丹明型简易Pd2+高选择性增强型荧光探针

用罗丹明B与水合肼一步反应简便制得罗丹明衍生物RBH,试验发现:在乙腈-水(CH3CN:H2O=4:1)溶液中,RBH对Pd2+具有高选择性和广泛的pH探测范围,其对常见金属离子不敏感,且常见钠、钾盐阴离子对Pd2+探测也无干扰作用。探针RBH与Pd2+结合后,RBH的吸收和荧光强度显著增加,其荧光强度增加24倍,检测时间仅需25 min。该Pd2+探针响应灵敏,最低检出限为1.76×10-6mol/L。RBH对Pd2+的识别过程为不可逆,且该探针可制成试纸检测mmol/L级别含Pd2+水样。     

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+。     

可视化辅助碳点荧光比色法检测水中痕量汞离子

利用巯基功能化碳点(M-CDs)构建用于检测水中Hg^2+的荧光探针。红外光谱证实M-CDs被巯基(-SH)成功修饰,透射电镜显示M-CDs的平均粒径约为4.88 nm。XRD晶型表征显示M-CDs具有类石墨烯结构。由于银硫醇盐的团聚作用,M-CDs溶液中加入Ag^+可快速形成M-CDs/Ag的棕色沉淀,并引起M-CDs的荧光猝灭。用PBS缓冲液(0.01 mol/L,pH 7.4)溶解沉淀物而形成检测Hg^2+的荧光传感器。在传感体系中加入Hg^2+后,M-CDs荧光明显恢复。在Hg^2+浓度为0.01~0.55 nmol/L范围内,检测体系荧光恢复强度与Hg^2+浓度成良好线性关系,检测限(LOD,3σ/k)4.2 pmol/L。该探针对Hg^2+表现出良好的选择性,同时可以通过可视化辅助判断探针的选择性。该传感器可用于对实际水样的检测,为Hg^2+污染监测提供技术依据。     

N-(8-对氨基苯磺酰)胺基喹啉的合成及其荧光性质的研究

合成了一种Zn2+荧光探针N-(8-对氨基苯磺酰)胺基喹啉(HQAS),探讨了HQAS与Zn2+的键合比和配位模式,以及不同pH,其它金属离子对Zn2+检测的影响.研究结果显示:该探针与Zn2+形成配合物,使其荧光增强,键合比为2:1,pH 7.2时荧光强度增大9.4倍.大多数金属离子几乎不干扰Zn2+的检测,Cu2+...     

一种定量测定Pb^2＋的新型荧光探针的合成及性能

以氟化硼络合二吡咯甲川类(BODIPY)染料为荧光团,二(2-羟基乙基)亚胺为识别体合成了一种新的对Pb2+具有高选择性的Pb2+荧光探针.在HEPES缓冲溶液(pH 7.4)中,当Pb2+浓度达到1.0×10-5 mol/L时肉眼可观察到探针荧光强度明显增强;当Pb2+浓度达到3.0×10-4 mol/L时,探针荧光强度增大20倍以上,且识别作用不受其它金属离子(Na+、Mg2+、Ca2+、Cu2+、Fe2+、Hg2+、Ag+、Cd2+、Cr3+、Fe3+)干扰.Pb2+浓度在0.2×10-5～5.0×10-5 mol/L范围内,探针荧光强度与Pb2+浓度有较好的线性关系,相关系数为0.998,检出限为0.2 μmol/L.     

一种8-羟基喹啉衍生物的制备及其对Mg2+的检测

该文以8-羟基喹啉-5-醛与苯甲酰肼反应后的酰腙作为荧光探针,利用1H NMR、13C NMR、MS以及荧光光谱对其结构和性质进行表征和测试。结果表明,在二甲基亚砜－4-羟乙基哌嗪乙磺酸（DMSO－HEPES）缓冲溶液（20 mmol/L,pH 7.0,95∶5,体积比）中,探针能够通过577 nm处的荧光增强选择性识别Mg2+,检出限达8.2 × 10－8 mol/L。此外,该探针还可以利用604、611 nm处的荧光增强来选择性识别Cd2+和Zn2+。理论优化计算表明,探针与Mg2+之间以2∶1形成配位后,HOMO与LUMO间的能级差缩小,电子云密度增大,从而在荧光光谱中表现出荧光增强。     

一种苯并咪唑衍生物的合成及对Mg2+的识别研究

本文利用2-氨基苯并咪唑和5-溴水杨醛反应制得一种具有聚集荧光增强性质的探针L。探针L可以在DMSO体系下对镁离子具有很好的识别效果,并且探针L随着水含量的升高荧光强度在逐渐增强,在水含量达到90%表现出明显的荧光增强现象且发射波长发生明显的红移,在495nm处出现最强发射峰,检测限达到3.49×10^-5 M,能够有效地检测Mg²⁺,同时探针L的AIE性质具有了成为发光材料的潜能。     

一个具有大Stokes位移的苯并噻唑类pH荧光探针

本文通过乙烯基将作为荧光团的苯并噻唑与作为H+受体的4-吡啶基桥联构筑了一个基于分子内电荷转移机制的pH荧光探针BTP2。研究表明该探针的Stokes位移为237 nm,远大于相应2-吡啶基类似物BTP1。滴定实验表明该探针的荧光在pH3.80至5.50之间随pH值增大而增强,且不受其他金属离子的干扰,具有检测胞内酸性细胞器pH的良好前景。探针pKa为4.72,略高于BTP1。4-吡啶基连接导致的更大的Stokes位移表明调节吡啶连接位置可以实现对该类探针分子Stokes位移的调控。     

用于检测Al3+和pH值的双功能荧光分子探针

利用荧光素(Fluorescein)对罗丹明6G(Rhodamine 6G)进行修饰,得到荧光分子探针R6G-Flu杂化物.此探针可特异性识别Al3+,检出限可低至10-8 mol/L级;向含有探针分子的溶液中加入Al3+后,溶液的颜色由无色变为粉色,并且在紫外灯下发出绿色荧光,可实现肉眼对10 μmol/L Al3+的定性检测.考察了不同pH值下R6G-Flu的荧光性质. 结果表明,此探针还可用于酸性范围(pH 3.00~6.00)和碱性范围(pH 8.00~10.50)内pH值的精确检测.实验结果表明,R6G-Flu是一种可用于Al3+和pH值检测的双功能荧光分子探针.     

Highly Sensitive and Fast‐Responsive Fluorescent Chemosensor for Palladium: Reversible Sensing and Visible Recovery

The well‐known rhodamine spiro‐lactam framework offers an ideal model for the development of fluorescence‐enhanced chemosensors through simple and convenient syntheses. Herein, we report a new tridentate PNO receptor, which was introduced into a rhodamine spiro‐lactam system to develop Pd²⁺‐chemosensor RPd4 , that displayed significantly improved sensing properties for palladium. Compound RPd4 shows a very fast response time (about 5 s), high sensitivity (5 nM ), and excellent specificity for Pd²⁺ ions over other PGE ions (Pt²⁺, Rh³⁺, and Ru³⁺). In addition, RPd4 displays quite different responses to different valence states of the Pd ions, that is, very fast response towards Pd²⁺ ions but slow response towards Pd⁰, which may provide us with a convenient method for the selective discrimination of Pd species in different valence states. According to proof‐of‐concept experiments, RPd4 has potential applications in Pd²⁺‐analysis in drug compounds, water, soil, and leaf samples. Owing to its good reversibility, RPd4 can also be used as a sensor material for the selective detection and visual recovery of trace Pd²⁺ ions in environmental samples.     

Fluorescent Probes for Pd2+ Detection by Allylidene–Hydrazone Ligands with Excellent Selectivity and Large Fluorescence Enhancement

Because palladium is widely used in various catalysts and converters, which results in a high level of contamination of water systems and the soil by residual palladium, there is an urgent need for Pd²⁺‐sensitive and ‐selective probes. Based on the special affinity of Pd²⁺ to conjugated double‐bond ligands, two fluorescence probes ( RPd2 and RPd3 ) that contain conjugated allylidene‐hydrazone ligands that link to colorless rhodamine‐spirolactam have been developed. The results show that conjugated allylidene‐hydrazones have a much better affinity toward Pd²⁺, and consequently provide the probes with more acute color change and fluorescence enhancement (≈170‐fold), and better selectivity over other metal ions (especially platinum‐group elements, or PGEs) than the unconjugated allyl‐hydrazine. With richer electron density and a more suitable stereo effect in the allylidene‐hydrazone group, RPd2 displays the best specificity toward Pd²⁺ and affords convenient detection by the naked eye. Its potential application for Pd²⁺‐contaminated water and soil‐sample analysis is revealed by proof‐of‐concept experiments.     

2-[3-氰基呋喃-2(5H)-亚基]丙二腈衍生物的合成及其对Pd2+的识别

通过两步反应合成了一种2-(3-氰基呋喃-2(5H)-亚甲基)丙二腈衍生物TCF-Pyn,该化合物在MeCN/磷酸缓冲容溶液(PBS)(V∶V=2∶8,PBS 2×10^-2 mol/L,pH=7.4)混合溶液中能高选择性荧光"OFF-ON"识别Pd²⁺,发射波长达到近红外区(653 nm).该探针具有较好的抗干扰能力、较宽的pH适用范围(3~8)和较低的检测限(6.92μmol/L).应用研究表明,TCF-Pyn能检测真实水样中的Pd²⁺,并可对活细胞中的Pd²⁺进行荧光成像.     

一种近红外发射荧光探针的合成及其荧光增强识别Hg2+

汞离子(Hg~(2+))由于高毒性以及容易对环境和人体造成损害,其检测越来越受到人们的重视。本文基于4-(二乙氨基)水杨醛设计合成了一种近红外发射荧光探针L,该探针可在MeCN/HEPES(体积比2/8,pH=7.4)缓冲溶液中高选择性地荧光增强识别Hg~(2+),其具有合成简便、抗干扰能力强、适用pH范围宽等特点。进一步研究表明,探针L可用于真实水样中Hg~(2+)的检测。     

Azomethine-H as a Highly Selective Fluorescent Probe for Fe3+ Detection in 100％ Aqueous Solution and Its Application in Living Cell Imaging

A simple assay for the detection of Fe³⁺ in water by means of fluorescence spectroscopy was developed based on a commercially available reagent, Azomethine-H(A-H), allowing sensing trace levels of Fe³⁺ with high selectivity over other cations. A significant fluorescence quenching of A-H at 424 nm was found after its binding with Fe³⁺ in 100% aqueous solution at pH=7.0, while other physiologically relevant metal ions posed little interference. The fluorescence responses can be well described by the modified Stern-Volmer equation. A good linear relationship(R²=0.9904) was observed up to 1.6×10^-5 mol/L Fe³⁺ ions. The detection limit, calculated via the 3σ IUPAC(international union of pure and applied chemistry) criteria, was 1.95×10^-7 mol/L. Moreover, the colorimetric and fluorescent response of A-H to Fe³⁺ can be conveniently detected by the naked eye, providing a facile method for visual detection of Fe³⁺. The proposed method was used to determine Fe³⁺ in water samples. Moreover, inverted fluorescence microscopy imaging using human umbilical vein endothelial cells shows that A-H can be used as an effective fluorescent probe for detecting Fe³⁺ in living cells.     

2-(2′-Hydroxyphenyl)-4(3H)-quinazolinone derivatives based fluorescent probes for mercury(II) via an intramolecular proton transfer mechanism

2-(2′,5′-Dihydroxy-phenyl)-4(3H)-quinazolinone (DHPQ), a new fluorescent dye that exhibits excited state intramolecular proton transfer (ESIPT) reaction and possesses good photophysical properties, is synthesised and used as fluorescent probe for detection of Hg²⁺. Mercuric ions can be detected and quantitated by measuring the fluorescent intensity decrease of the probe. The decrease of fluorescence intensity of DHPQ upon the addition of Hg²⁺ was attributed to the blocking of ESIPT reactions of DHPQ and quenching its fluorescence. The analytical performance characteristics of the proposed Hg²⁺ probe were investigated. The probe can be applied to the quantification of Hg²⁺ with a concentration range covering from 8.0?×?10^?7 to 2.0?×?10^?4?mol?L^?1, with a working pH range of 5.5–6.5. It shows excellent selectivity for Hg²⁺ over other transition metal cations. The proposed method was testified for the Hg²⁺ assay in river water samples with satisfying recoveries.     

Highly selective chromogenic and fluorogenic probe based on benzothiazole-thiosemicarbazone Schiff base for detection of copper (II) in real samples

Copper is the third most abundant essential transition metal ion in the human body. It's responsible for important activities in many living things, but excessive intake of Cu²⁺ can lead to a range of diseases. A colorimetric and turn-off fluorescent probe (E)-2-(5-(benzothiazol-2-yl)-2-(diethylamino)-4-hydroxybenzylidene)-N-phenylhydrazine-1-carbothioamide ( ZTR ) was designed and synthesized by thiosemicarbazone Schiff base as a specific complexes site strategy to achieve highly specific Cu²⁺ detection. The fluorescence of the probe ZTR solution fell dramatically when Cu²⁺ was added, and its appearance changed from dazzling blue to nearly colorless. The simple structure and readily available fluorescent probe provide a novel approach for the quantitative detection of Cu²⁺ in the linear range from 0 to 0.12 μM, with a detection limit down to 16 nM, and with high selectivity for Cu²⁺ over 15 other metal ions. Job’s plot analysis showed that probe ZTR and Cu²⁺ formed a 1:1 coordination complex. In addition, because of its low detection limits and fast response time, the created fluorescent molecule was effectively used to study the target ions on test paper strips and in water samples.))     

A highly sensitive naphthalimide-based fluorescent probe for detection of Cu2+ via selective hydrolysis reaction and its application in practical samples

A novel fluorescent probe CN3, containing 1,8-naphthalimide and picolinate units, was synthesized, and its structure was characterized by ¹H nuclear magnetic resonance spectroscopy (H NMR), ¹³C nuclear magnetic resonance spectroscopy (C NMR), and mass spectroscopy techniques. The detection property of CN3 toward copper ions (Cu²⁺) has been investigated in ethanol–HEPES buffer (v/v = 1/1, pH = 7.40) solution by UV–Vis absorption and fluorescence emission spectra. The results showed that CN3 had a highly selective and sensitive fluorescence quenching response to Cu²⁺, which was attributed to the generation of weak fluorescent N-ethyl-4-hydroxyphenyl-1,8- naphthalimide (compound 2) in polar ethanol–HEPES buffer (v/v = 1/1, pH = 7.40) via selective hydrolysis reaction. The detection of CN3 for Cu²⁺ was not influenced in the presence of other competing metal ions, and the limit of detection was as low as 50.0 nM. Therefore, the color of CN3 changed from colorless to yellowish when the Cu²⁺ was added. Furthermore, the fluorescent probe CN3 was utilized to detect Cu²⁺ in real water samples with fine performance.