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.     

一种新型罗丹明类Hg2+荧光探针的合成与分析应用

设计合成了一种可逆的Hg2+荧光增强型分子探针3’,6’-双(二乙氨基)-2-((2-羟基-4-甲氧基苯亚甲基)氨基)螺[异吲哚-1,9’-氧杂蒽]-3-硫酮(RBS),并利用红外光谱、元素分析、核磁等方法对探针结构进行表征。探针本身荧光很弱,与Hg2+结合后荧光显著增强,由此,建立了Hg2+测定的新方法。该方法对Hg2+测定的线性范围为5.00×10-9～1.10×10-6mol/L,检出限为2.82×10-9mol/L,具有操作简单、灵敏度高、选择性好、线性范围宽等特点。将该方法用于河水及土壤样品中Hg2+的加标回收实验,结果满意。     

香豆素并查尔酮氰离子荧光探针的合成及传感性能研究

合成了以香豆素并查尔酮结构为发光团、共轭的C=C键为反应位点构筑新型氰离子荧光探针1.在DMSO-H2O(v:v=7:3)的溶液体系中,利用紫外可见吸收光谱和荧光光谱探究了荧光探针1对CN-的刺激响应,当体系中加入CN-后,探针溶液显示出明显的颜色变化,裸眼观察到溶液的颜色由橙色变为黄色,而加入ACO-、H2 PO4-...     

一种检测水合肼荧光探针的合成与应用

基于香豆素类染料,设计合成了一种具有较高选择性和灵敏度,可在生理条件(pH 7.4)下检测水合肼的荧光探针,同时利用核磁共振和高分辨质谱对探针的分子结构进行了表征。基于水合肼进攻探针分子结构中的4-丁酸酯,生成酚氧负离子,同时发生分子内环化反应后生成具有强烈荧光的亚胺香豆素,实现了探针分子对水合肼的检测。光谱学研究表明,当向探针溶液加入水合肼(0~100μmol/L)后,探针溶液在绿色光谱区域(502 nm)呈现一个显著的荧光增强响应(增强至55倍)。并且,探针可以检测相对较低浓度的水合肼,检出限为1.7×10~(-7)mol/L。此外,相对于其他阴离子和亲核试剂,探针对水合肼的识别显示出较高的选择性和灵敏度。探针成功实现了细胞内水合肼的荧光成像,证明其在细胞成像中具有潜在的应用能力。     

一种基于查尔酮衍生物的荧光探针对巯基氨基酸的检测及细胞成像

生物硫醇(如半胱氨酸(Cys)、同型半胱氨酸(Hcy)及谷胱甘肽(GSH))与生物体和细胞中的许多生理和病理过程密切相关。荧光探针是对生物硫醇灵敏检测与成像的有力工具。本文合成了一种可检测生物硫醇的基于2′-羟基查尔酮荧光团开启型荧光探针1。探针中的2,4-二硝基苯磺酸酯基团既作为反应识别基团,又作为荧光猝灭基团。在DMSO/Tris(体积比8/2,pH=8.4)中,探针1与生物硫醇反应后释放出前体化合物3,3具有激发态分子内质子转移(ESIPT)和聚集诱导发光(AIE)特性,从而导致长波长荧光发射及较大的斯托克斯位移。探针1具有合成简单、灵敏度高、选择性高、细胞毒性低等优点,可以方便地检测溶液和活细胞中的生物硫醇。     

基于查尔酮衍生物的铜离子探针的设计合成

以N-丁基-吲哚-3-甲醛和2-乙酰吡啶作为原料,通过羟醛缩合反应设计合成一种查尔酮衍生物(E)-3-(1-丁基-1氢-吲哚基)-1-(2-吡啶基)丙烯基酮(L)。 通过核磁共振波谱仪、质谱和傅里叶变换红外光谱技术手段表征了目标分子的结构。 结果表明,探针L对Cu²⁺表现出专一的选择性和高的灵敏度,溶液颜色由淡黄色变为红色,能够直接通过肉眼识别,检测限低至27.8 nmol/L,探针L与Cu²⁺的配位比为1∶1,结合核磁滴定和理论计算研究了探针L对Cu²⁺的识别机制。     

一种罗丹明类次氯酸荧光探针的合成与分析应用

通过一步反应合成了一种次氯酸(HOCl)荧光探针罗丹明6G酰肼,利用核磁和质谱对探针结构进行表征,并研究了其检测HOCl的荧光性能。实验结果表明,探针对HOCl的荧光分析具有高的灵敏性和选择性。利用不可逆的氧化还原反应,探针在中性溶液中快速产生与HOCl浓度呈线性比例的荧光增强信号,检测的线性范围为2~400μmol/L,检出限为0.06μmol/L,其他常见活性氧物种对检测影响小。探针能检测自来水中HOCl的含量,并在HeLa活细胞中实现了HOCl的荧光成像。     

新型荧光素类细胞钙离子荧光探针Fluo-Cl的设计、合成及表征

设计合成了一种新型荧光素类细胞钙离子荧光探针, 并对其结构及光谱特性进行了表征.     

一种新型的荧光探针及其在表面活性剂溶液胶束形成过程中的应用

近年来,具有分子内共扼的电荷转移化合物用作荧光探针来研究微环境的特性得到较大的发展,由Lout坛Law等提出的p-N,N一二烷基氨基爷叉丙二睛类化合物,其吸收光谱,特别是荧光光谱具有强烈的溶剂极性依赖性,即荧光光谱的峰值波长依赖于所处环境的极性,并有良好的线性关系。     

一种检测生物硫醇荧光探针的合成与应用

基于硫醇诱导的迈克尔加成反应阻断探针的光诱导电子转移过程(PET)合成了一种基于氟化硼络合二吡咯甲川(Bodipy)类染料的荧光探针,该探针具有高灵敏度和选择性,可在生理条件下检测硫醇。利用核磁和高分辨质谱对探针结构进行了表征。当向探针溶液加入硫醇(0~1 000μmol/L)时,可在探针溶液的绿色光谱区域引起一个显著的荧光增强响应(增强至150倍)。同时,探针可以检测相对较低浓度的硫醇,对于含有硫醇的氨基酸(半胱氨酸、谷胱甘肽和高半胱氨酸)的检出限分别为4.5×10~(-7),1.2×10~(-7),2.1×10~(-7)mol/L。此外,相对于其他氨基酸,探针对硫醇具有较高的选择性和灵敏度。该方法成功实现了细胞内硫醇的荧光成像,证明该荧光探针在生物体系中具有潜在的应用能力。     

Anaphthalimide-based fluorescent probe for mercaptocontaining compounds

A polarity-sensitive fluorescent probe MNP was rationally designed and synthesized with naphthalimide as the fluorophore and maleimide as the receptor for thiols. MNP is weakly fluorescent due to the photoinduced electron-transfer(PET) from the fluorophore to the receptor, and it displays evidently solvatochromic UV–vis and fluorescence spectra: the emission shifted from 495 nm in n-hexane to545 nm in phosphate buffer solution. Michael addition reaction between thiols and the maleimide in MNP inhibited the PET process, which led to about eight-fold fluorescence enhancement. In addition,MNP showed highly sensitivity to mercapto-containing proteins and it could detect as low as 20.4 mg/m L of BSA in PBS. MNP has potential in fluorescent imaging of thiols in living cells.     

罗丹明类测定三聚氰胺的荧光探针的合成及应用研究

报道了罗丹明乙二醛酰腙的合成及与三聚氰胺的反应。在pH 3.0的缓冲溶液中三聚氰胺对罗丹明乙二醛酰腙的荧光强度有增强作用,其增强程度与三聚氰胺的浓度成正比,据此建立了一种新的测定三聚氰胺含量的荧光分析法。该方法线性范围为0.5~10.0 mg/L,r=0.994,检出限为0.15 mg/L,样品测定的RSD为1.7%(n=7)。     

A highly selective fluorescent probe for Hg based on a rhodamine-coumarin conjugate

A fluorescent probe 1 for Hg²⁺ based on a rhodamine-coumarin conjugate was designed and synthesized. Probe 1 exhibits high sensitivity and selectivity for sensing Hg²⁺, and about a 24-fold increase in fluorescence emission intensity is observed upon binding excess Hg²⁺ in 50% water/ethanol buffered at pH 7.24. The fluorescence response to Hg²⁺ is attributed to the 1:1 complex formation between probe 1 and Hg²⁺, which has been utilized as the basis for the selective detection of Hg²⁺. Besides, probe 1 was also found to show a reversible dual chromo- and fluorogenic response toward Hg²⁺ likely due to the chelation-induced ring opening of rhodamine spirolactam. The analytical performance characteristics of the proposed Hg²⁺-sensitive probe were investigated. The linear response range covers a concentration range of Hg²⁺ from 8.0 × 10⁻⁸ to 1.0 × 10⁻⁵ mol L⁻¹ and the detection limit is 4.0 × 10⁻⁸ mol L⁻¹. The determination of Hg²⁺ in both tap and river water samples displays satisfactory results.     

Determination of non-protein cysteine in human serum by a designed BODIPY-based fluorescent probe

A novel fluorescent probe is designed and synthesized for the determination of cysteine in biological samples by incorporating 2,4-dinitrobenzenesulfonyl (DBS) group as a quencher into the BODIPY skeleton. The BODIPY-based probe itself shows weak fluorescence due to the strong intramolecular charge transfer process. Upon reaction with cysteine, however, the probe produces a rapid and large fluorescence enhancement through the removal of the DBS unit by nucleophilic aromatic substitution. This valuable property leads to the development of a new and simple method for cysteine assay. Under the optimized conditions, the fluorescence enhancement value is directly proportional to the concentration of cysteine in the range 2-12 μM, with a detection limit of 30 nM (S/N = 3). The applicability of the developed method has been successfully demonstrated on the determination of non-protein cysteine in human serum. Compared to most of the existing fluorescent probes proposed for cysteine, the BODIPY-based one exhibits an excellent overall performance in terms of selectivity, sensitivity and simplicity.     

An intramolecular charge transfer fluorescent probe: synthesis and selective fluorescent sensing of Ag+

An intramolecular charge transfer (ICT) fluorescent probe, in which the thiourea derivative moiety is linked to the fluorescent 4-(dimethylamino) benzamide, has been designed and synthesized. The ions-selective signaling behaviors of the probe were investigated. Upon the addition of Ag+, an overall emission enhancement of 14-fold was observed. Compound 1 displayed highly selective chelation enhanced fluorescence (CHEF) effect with Ag+ over alkali, alkali earth metal ions and some transition metal ions in aqueous methanol solutions. The prominent selective and efficient fluorescent enhancing behavior could be utilized as a new chemosensing probe for the analysis of Ag+ ion in aqueous environment.     

A borondipyrrolemethene-based turn-on fluorescent probe for silver ion with high sensitivity and selectivity and its application in water samples and living cells

A borondipyrrolemethene-based compound (1) is synthesized and used as a “turn-on” fluorescent probe for silver ions (Ag⁺). The probe displays highly sensitive fluorescence response toward Ag⁺ with a 40-fold fluorescence enhancement when 60 μM of Ag⁺ is added. The fluorescence intensity of the probe is linearly dependent on Ag⁺ concentration ranging from 0.05 to 60 μM. And the detection limit (LOD) can reach 0.02 μM, which complies with the standard of World Health Organization (WHO) for drinking water (0.9 μM). Moreover, the probe shows remarkable selectivity for Ag⁺ over other metal ions. Furthermore, the response behavior of 1 toward Ag⁺ is pH independent in the neutral range from 6.0 to 8.0. The response of 1 toward Ag⁺ is fast (response time is less than 2 min) and reversible chemically. What’s more, the sensing mechanism of probe 1 toward Ag⁺ is verified by mass spectra (MS) and density functional theory (DFT) calculations. In particular, the probe is applied for detection of Ag⁺ in water samples and living cells successfully.     

A simple,water-soluble,Fe3+-selective fluorescent probe and its application in bioimaging

A simple,water-soluble,Fe³⁺-selective fluorescent probe,derived from rhodamine B,was synthesized and characterized.The probe exhibits a fluorescence response toward Fe³⁺ with acceptable sensitivity and selectivity and even facilitates visual or naked-eye detection of Fe³⁺.The experiment results show that the response of the probe to Fe³⁺ is pH-independent over a wide range of 4.0-10.0.In addition,fluorescence microscopic imaging experiments have proven that the probe is cell permeable and can be used for monitoring intracellular Fe³⁺ in living cells.     

Development of a light-up fluorescent probe for HRAS G-quadruplex DNA

The development of small-molecule G-quadruplex DNA probes has attracted significant attention in recent years. However, G-quadruplexes can display a wide variety of topologies, which process different structures and functions. Therefore, selective discrimination one G-quadruplex structure over another is promising. Herein, we reported the design, synthesis and biological evaluation of a long-chain fatty amine functionalized triphenylamine-quinolinium conjugate 1b. Significant enhancement of the fluorescence intensity (over 180 fold) was observed when 1b bound with HRAS G-quadruplex DNA, while much weaker enhancements were presented in the presence of other G-quadruplexes (45–90-fold) and single/double-stranded DNAs (less than 20-fold), indicating 1b had an excellent selectivity to HRAS. The details of the interactions were investigated by UV–Vis, FID and CD analysis. The results show 1b could interact and stabilize HRAS structure mainly by π-π stacking binding mode. The introduced amine chain of the structure core was found to be better in the terms of inducing selectivity toward G-quadruplex structure. In addition, the application of 1b as a fluorescent agent for living cell imaging was also demonstrated.     

A new fluorescent probe with ultralow background fluorescence for imaging of endogenous cellular selenol under oxidative stress

A new fluorescent probe (Rhod-Sec) for selenol detection with ultralow background fluorescence have been developed in this paper, which showed a 380-fold off-on fluorescence response, and can be applied to visualize the fluctuation of selenol in HepG2 cells through LPS-induced cells oxidation resistance.