Design and synthesis of caged fluorescent nucleotides and application to live-cell RNA imaging

A binary photocontrolled nucleic acid probe that contains a nucleotide modified with one photolabile nitrobenzyl unit and two hybridization-sensitive thiazole orange units has been designed for area-specific fluorescence imaging of RNA in a cell. The synthesized probe emitted very weak fluorescence regardless of the presence of the complementary RNA, whereas it showed hybridization-sensitive fluorescence emission at 532 nm after photoirradiation at 360 or 405 nm for uncaging. Fluorescence suppression of the caged probe was attributed to a decrease in the duplex-formation ability. Caged fluorescent nucleotides with other emission wavelengths (622 and 724 nm) were also synthesized in this study; they were uncaged by 360 nm irradiation, and emitted fluorescence in the presence of the complementary RNA. Such probes were applied to area-specific RNA imaging in a cell. Only probes in the defined irradiation area were activated by uncaging irradiation, and subnuclear mRNA diffusion in a living cell was monitored.     

比率型过氧化氢荧光探针的合成及成像应用

采用6-甲氧基苯并噻唑-2-羟基喹啉作为双光子荧光团、硼酸酯作为过氧化氢（H2O2）识别基团，合成比率型检测H2O2的双光子荧光探针{6-甲氧基-2-[6-(4,4,5,5-四甲基-1,3,2-二氧硼杂环戊烷-2-基)喹啉-2-基]苯并[d]噻唑}（MQH2O2）。利用荧光光谱和双光子荧光光谱对探针进行H2O2响应能力的评估，结果显示探针具有良好的H2O2比率响应（30 min内比率信号增强约25.4倍、检出限低至38.6 nmol/L）和双光子性质（最大双光子荧光活性截面为150 GM）。通过双光子共聚焦成像完成了细胞和大脑组织成像，结果表明该探针能够实现脑卒中诱导细胞氧化应激的原位成像分析。     

Synthesis and application of polymeric fluorescent whitening agents

From p-toluic acid, a series of polymeric fluorescent whitening agents (FWA) was synthesized. In the paper are given the details for the synthesis of the FWA and their intermediates. The products are water-dispersible or water-soluble, have good affinity with hydrophobic fabrics, affect the soil-releasing effect on polyester, soiled or aged cotton fabrics, and can be incorporated into concentrated fabric conditioner, a product type using FWA that is being developed. Polymeric FWA add excellent brightness to polyester and soiled or aged cotton for which the usual anionic FWA have little effect.     

阳离子荧光染料的合成及其性能研究

合成了一种新型双阳离子型荧光染料—反,反-1,4-双{2-[4-(N-乙基)溴化吡啶基]乙烯基}苯(DPPB),采用红外光谱和核磁共振谱仪对其进行了结构表征,通过染色实验研究其在腈纶织物上的染色性能及色牢度,同时研究了其单光子荧光性能。结果表明,DPPB的荧光性能良好,在腈纶织物上有良好的染色性能,所染织物具有蓝绿色荧光效果。     

双功能荧光磁性复合物的合成及应用

荧光磁性复合物兼有磁性微粒的快速分离和量子点的优异荧光特性,集选择、标记、分离、检测等功能为一体,在生物、化学、医学等交叉科学领域具有广泛的应用。介绍了磁性纳米颗粒、量子点和荧光磁性复合物的应用前景;综述了用层层自组装法、微乳液法、Stber法等方法制备荧光磁性复合物并进一步阐释了其在细胞分离、药物运输等方面的应用,结合当前的研究现状,分析了其主要的发展方向和仍需解决的问题。     

Synthesis and characterization of fluorescent perylene bisimide-containing glycopolymers for Escherichia coli conjugation and cell imaging

Fluorescent glycopolymers were prepared via combined atom transfer radical polymerization (ATRP) and ‘Click Chemistry’ in one-pot synthesis, in the presence of 2-azidoethyl methacrylate (AzEMA), 2-propynyl α-d-mannopyranoside, N,N′-bis{2-[2-[(2-bromo-2-methylpropanoyl)oxy]ethoxy]ethyl}perylene-3,4,9,10-tetracarboxylic acid bisimide (PBI-Br), copper (I) bromide catalyst and pentamethyldiethylenetriamine (PMDETA) ligand. Simultaneous ATRP and ‘Click Chemistry’ is an attractive method for the synthesis of functional glycopolymers as the reaction conditions are compatible with ATRP of an azide monomer, as long as an alkynyl-functionalized carbohydrate is available for click coupling reaction. The fluorescent glycopolymers were characterized by ¹H NMR, FT-IR, UV-visible absorption, fluorescence and X-ray photoelectron spectroscopies, as well as by gel permeation chromatography. Incubation of Escherichia coli (E. coli DH5α) with the fluorescent glycopolymers yielded green fluorescent bacterial clusters. The low cytotoxicity level of the fluorescent glycopolymers was revealed by incubation with 3T3 fibroblasts, macrophages and KB cells in 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assays in vitro. Subsequently, the water-soluble, biocompatible and fluorescent glycopolymers were used as effective fluorescent cell labeling agents.     

碳点荧光探针的合成及其在芦丁含量检测中的应用

以新鲜银杏叶为碳源，采用水热法制备出水溶性好、高稳定性的银杏叶碳点（CDs）。通过透射电子显微镜（TEM）、傅立叶变换红外吸收光谱仪（FTIR）、X射线衍射（XRD）、紫外-可见光谱（UV-Vis）和荧光光谱表征了银杏叶CDs的结构及光学特征。基于芦丁（Rutin）对CDs荧光的猝灭现象，构建了高选择性与高灵敏度的荧光探针测试芦丁含量。结果表明，10-80μmol/L的Rutin与CDs的荧光猝灭程度之间呈现良好的线性关系，线性方程为ln(F/F0)= -0.0175c(μmol/L)-0.01492，线性相关系数R 为0.9997。检测限为1.5μmol/L。另以柠檬酸为碳源，制备了柠檬酸CDs，两种CDs荧光探针用于检测槐米中的Rutin含量，检测结果一致。     

基于咖啡酸的高灵敏性水合肼荧光探针的合成及应用

以天然产物咖啡酸为原料，设计合成了一种可快速识别水合肼（N2H4）的咖啡酰基荧光探针ED。通过1HNMR、13CNMR和HRMS对其结构进行了表征。通过荧光光谱法研究发现探针ED对N2H4具有高选择和高灵敏性识别，检测过程中检测极限为0.31 μmol/L，最适pH范围为3~8，响应时间为48 s。通过MS和1HNMR证明探针ED对N2H4的荧光响应过程中结构中不饱和酮结构与N2H4反应后生成吡唑环。此外，探针ED与N2H4作用后溶液颜色从无色变为黄色，可实现N2H4的“裸眼检测”，并成功用于水样中N2H4的检测。 关键词：咖啡酸；荧光探针；水合肼；快速识别；检测试纸     

Synthesis and evaluation of a fluorescent non-peptidic cholecystokinin-B/gastrin receptor specific antagonist for cancer cell imaging

Fluorescent labeling has enabled a better understanding of the relationships between receptor location, function, and life cycle. Each of these perspectives contributes new insights into drug action, particularly for G protein‐coupled receptors (GPCRs). The aim of this study was to develop a fluorescein derivative, FLUO‐QUIN—a novel antagonist of the cholecystokinin‐B/gastrin receptor. A radioligand‐binding experiment revealed an IC₅₀ of 4.79 nm, and the antagonist inhibited gastric acid secretion in an isolated lumen‐perfused mouse stomach assay (up to 51 % at 100 nm) . The fluorescence properties altered upon binding to the receptor, and the fluorophore was quenched to a greater extent when free than in the bound form. FLUO‐QUIN specifically bound to human pancreatic carcinoma cells, MiaPaca‐2, which are known to express the receptor, as evidenced by rapid clustering followed by time‐dependent receptor internalization. This proves the stability of FLUO‐QUIN and its ability to penetrate vesicular membranes and reach various cell targets. Hence it might be used as an agent for the detection of CCK‐B‐receptor‐positive tumors by fluorescence imaging.     

Facile synthesis of fluorescent porous zinc sulfide nanospheres and their application for potential drug delivery and live cell imaging

Fabrication of intrinsically fluorescent porous nanocarriers that are simultaneously stable in aqueous solutions and photostable is critical for their application in drug delivery and optical imaging but remains a challenge. In this study, fluorescent porous zinc sulfide nanospheres were synthesized by a facile gum arabic-assisted hydrothermal procedure. The morphology, composition and properties of the nanospheres have been characterized by field-emission scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, N(2) adsorption-desorption analysis, thermal gravimetric analysis, fourier transform infrared spectrograph, optical measurement, dynamic light scattering, and cytotoxicity assay. They exhibit larger surface area, excellent colloidal stability, photostable fluorescent signals, and good biocompatibility, which makes them promising hosts for drug delivery and cellular imaging. The fluorescent dye safranine-T was employed as a drug model and loaded into the porous nanospheres, which were delivered to human cervical cancer HeLa cells in vitro for live cell imaging.     

Preparation of thermoresponsive fluorescent carbon dots for cellular imaging

Nowadays, carbon dots (CDs ) have aroused widespread interest due to their chemical stability, biocompatibility as well as low toxicity. Herein, polymerizable CD monomers were synthesized through amidation between hydrophobic CDs and methacryloyl chloride, which has emerged as a facile method for preparing various fluorescent CD monomers. The fluorescent polymerizable CDs were copolymerized with N‐ isopropylacrylamide (NIPAM ) to form thermoresponsive fluorescent nanoparticles. The poly(NIPAM ) (PNIPAM ) grafted hydrophobic CDs (CDs ‐g ‐PNIPAM ) have excellent dispersivity in water, rendering hydrophobic CDs with fluorescence properties in aqueous media. Moreover, CDs ‐g ‐PNIPAM nanocomposites show a remarkable thermoresponsive behavior, and the fluorescence intensity decreases progressively with increase in temperature. Cytotoxicity tests show that CDs ‐g ‐PNIPAM nanocomposites have great biocompatibility. When the CDs ‐g ‐PNIPAM nanocomposites were cultured with HaCaT cells at a concentration of 2000 µg mL ^?1, cell viability was maintained over 85%. Benefiting from the copolymerization of NIPAM , the excitation‐independent fluorescence of CDs ‐g ‐PNIPAM nanocomposites can be used for cellular labeling and show long‐term biostability in a cellular environment. © 2016 Society of Chemical Industry     

水杨醛席夫碱荧光化合物的合成及在棉织物上的印花应用

以水杨醛、己二胺、邻苯二胺为原料，通过醛基与氨基的缩合反应合成了两种水杨醛希夫碱荧光化合物SSB1和SSB2，并将化合物SSB2制成不同荧光染料浓度的印花浆对棉织物进行印花处理。对所得化合物进行了表面形貌、化学结构、色谱及热稳定性能的表征；并考察了SSB2荧光印花棉织物的荧光性能、颜色性能、色牢度性能。结果表明：SSB1，SSB2的产率分别为88.8%和86%，相对最大荧光强度分别为8305和5444，相转变温度分别为75℃和165℃；所得SSB2荧光棉印花织物耐皂洗牢度最高可达4级，SSB2荧光染料用量在10%的时候，分别达到最佳的颜色深度和荧光强度。     

Synthesis,characterization, and application of fluorescent electrically conducting copolymer/metal-oxide nanocomposites

ABSTRACT

Solution polymerization of aniline in the presence of fluorescent organic dyes was carried out at 0–5°C for 2 h under nitrogen atmosphere with FeCl₃ as an initiator. The copolymers were prepared under different experimental conditions. The prepared copolymers were characterized by various analytical tools. The electrical conductivity was measured. From the absorbance and emission intensity values the order of reaction was calculated. Further, its application toward the reduction of nitrophenol was done and the apparent rate constant (K_app) was calculated. The Fourier Transform Infra Red (FTIR) spectrum confirmed the presence of benzenoid, quinonoid, and azo functionalities.     

过氧化氢近红外荧光探针的合成及在食品安全检测中的应用

分别以半花菁和硼酸酯作为荧光母体和识别基团,设计合成了一个过氧化氢荧光探针TC-BOR,其结构通过1HNMR、13CNMR和高分辨质谱(HRMS)进行确证.该探针与过氧化氢反应后的产物(TC-OH)可发射出723 nm的荧光,与加入过氧化氢前相比荧光强度增强约55倍,响应时间不到7 min,最低检测限为2.27μmol...     

Design of polymers for migration imaging application II: Synthesis and polymerisation of p-isobutyl styrene

A copolymer series was synthesized for migration imaging applications from isobutyl methacrylate and isobutyl styrene such that each homopolymer and all copolymers had glass transition temperature (T_g) near 55°C. The T_g of poly (p-isobutylstyrene) was predicted from literature values of similar polymers to be near 55°C. Poly (p-isobutylstyrene) was synthesised by acetylation of isobutyl benzene, reduction of p-isobutylacetoph-enone to the carbinol, dehydration to p-isobutylstyrene and free radical polymerisation to the polymer. The T_g of the homopolymer was 55°C, in excellent agreement with the predicted value. Copolymers of isobutyl methacrylate and p-isobutyl styrene were synthesised and their T_g's measured across the series by DSC (57°C ± 5°C). refractive index temperature coefficient (42°C ± 5°C). The copolymer series was also characterised by melt viscosity measurements.     

Synthesis,characterization, and application of composite alginate microspheres with magnetic and fluorescent functionalities

Composite alginate microspheres were synthesized via a modified emulsification technique and characterized by inverted optical microscope, transmission electron microscope, ζ‐potential analyzer, UV–vis spectrophotometer, luminescence spectrometer, and vibrating sample magnetometer. The results show that the synthetic parameters including the weight ratio of maghemite nanoparticles to alginate, hydrophile‐lipophile balance (HLB) value, stirring speed, and CaCl₂ dripping rate play important roles in the synthesis of microspheres. Furthermore, the composite alginate microspheres exhibit good superparamagnetism and fluorescence, which can serve both as magnetic resonance contrast agents and optical probes for biological imaging. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

A highly sensitive and selective fluorescent probe for Hg2 + and its imaging application in living cells

Two rhodamine-based Hg^2 + probes L1 and L2 were prepared and confirmed by NMR, MS and crystal data. The sensing behavior of these probes was studied by UV–visible and fluorescence spectroscopy. The probe L1 couldn't be widely applied in aqueous media or mixed media because of its poor solubility. However, the probe L2 displayed selective and sensitive fluorescence enhancement response to Hg^2 + at physiological pH value for biological use. The selectivity of this system for Hg^2 + over other metal ions was remarkably high, and its sensitivity was at ppb level. The probe L2 responded rapidly to Hg^2 + in aqueous solutions with a 1:1 stoichiometry and was successfully applied to image Hg^2 + in living cells.     

长波长过氧化氢荧光探针的合成及在食品安全检测中的应用

分别以半花菁和硼酸酯作为荧光母体和识别基团，设计、合成了一个过氧化氢的荧光探针TC-BOR，并利用1HNMR、13CNMR和HRMS 对其结构进行表征。实验表明，探针与过氧化氢反应后的产物（TC-OH）可发射出723 nm的荧光，荧光强度增强55倍，响应时间低于7 min，检测下限为2.27 μmol·L-1。随后，成功的将TC-BOR用于食品和活细胞中的过氧化氢的定性、定量检测，这可为食品中过氧化氢的快检检测提供一种新方法。