荧光聚合物研究进展*

本文总结了近年来荧光聚合物的研究进展,主要介绍了荧光聚合物的分类：按其溶解性能可分为非水溶性、水溶性和两亲荧光聚合物三大类;荧光聚合物的合成：荧光化合物为引发剂、荧光化合物为链转移剂、荧光功能单体聚合、荧光化合物与聚合物的化学键合、非荧光功能单体聚合等五种制备荧光聚合物的设计合成方法;荧光聚合物的应用：荧光聚合物在荧光化学传感器、荧光分子温度计、荧光造影、药物载体、荧光探针等方面的应用研究。     

Recognition of myo-inositol 1,4,5-trisphosphate using a fluorescent imidazolium receptor

The first example of an imidazolium-based fluorescent receptor for D-myo-inositol 1,4,5-trisphosphate (IP(3)) is reported in this study. The fluorescent receptor 1 bearing four imidazolium and pyrene groups displayed a large fluorescent quenching effect with myo-IP(3) compared to fluorescent changes with various IP series, pyrophosphate, and ATP.     

手术导航用荧光探针

荧光成像技术因具有操作简便、分辨率高、安全性好且可实时成像等优势,在术中导航中具有广阔的应用前景。虽然目前还没有靶向荧光探针在临床上得到批准,但已经有相当一部分荧光探针进入了临床试验阶段。最早进入临床试验的是一些偶联肿瘤靶向配体的荧光染料,例如近红外菁染料(IRDye800CW)标记的肿瘤特异抗体,叶酸标记的异硫氰酸荧光素(EC17)等。近来,结构更复杂的荧光探针如酶反应激活型探针和PET/荧光双模态探针也逐步进入临床试验。本文依据近年来手术导航用荧光探针的最新研究进展,分别就受体介导的靶向荧光探针、可激活型靶向荧光探针、近红外二区(NIR-Ⅱ)荧光探针、多模态荧光探针和诊疗一体化探针进行了分类讨论,重点对正在进行临床研究及具有临床转化前景的荧光探针的分子设计原理进行了分析与总结,并对手术导航用荧光探针未来的发展进行了展望。     

A fluorescent polymer dots positive readout fluorescent quenching lateral flow sensor for ractopamine rapid detection

A fluorescent polymer dots positive readout and sensitive lateral flow assay (LFA) based on fluorescent quenching has been developed to detect ractopamine (Rac), a chemical residue in food, harmful to human health. Compared with traditional LFA strips, these fluorescent quenching LFA (FQLFA) strips provide a positive correlation method that allows users to obtain results from a weak fluorescent signal. The immunoassay strip scheme is based on the fact that fluorescent polymer dots (FPDs) in close proximity to gold nanoparticles (AuNPs) represent a strong fluorescent quenching. We show that the FQLFA strips can be used as a source to quantitatively analyze Rac in phosphate buffers (PB), swine urine and muscle tissue samples. The lowest detection limitation of the FQLFA was 0.16 ng mL⁻¹. Our results indicated that this novel scheme was more suitable for rapid detection of small molecules.     

Preparation of Micron-size Functional Fluorescent Microspheres

As a kind of special functional microspheres, fluorescent polymer microspheres could be used in cell label and separation, blood flow assay, flow cytometer marking, chemical reaction assay,and in analyst of the transform and diffusion of particles in soil 1. However, one of the most important applications of fluorescent microspheres is in the high-throughput screening of drugs (HTS) 2. Through affinity interaction, radioactive ligands (latent drugs) are bound to fluorescent microspheres covered by receptor, and luminescence is produced by radioactivity, so ligands can be assayed and screened.In this study, we developed a technique for preparing micron-size fluorescent microspheres with different functional groups. The methods included the synthesis of micron-size polystyrene microspheres through the dispersion polymerization of styrene in different media such as ethanol,ethanol-water, and isopropanol; the functional polystyrene microspheres were prepared by introduction of functional monomers into the reaction system of styrene; the functional fluorescent microspheres were obtained by the way of dying functional microspheres in the fluorescent material's ethanol solvent.The average diameter of microspheres was in the range of 1～10 μm, and the distribution was normal distribution. The functional groups included -OH, -CHO, -COOH, -CONH2, and SO3H. The absorbing spectrum and exciting spectrum were tested, the results showed that the maximal absorbance of fluorescent microsphere was near 306.5 nm, and its maximal excitation was near 362 nm. The excitation spectrum of fluorescent material (DPO) and fluorescent microspheres were shown in figure 1, and it indicated that the developed fluorescent microspheres showed the same excitation behavior like DPO, which related to the fluorescent microspheres had stable luminescence property.     

改性SiO2载体对邻菲咯啉钌荧光特性及氧敏感荧光膜性能的影响

为提高极性荧光指示剂Ru(dpp)₃Cl₂在非极性硅橡胶中的分散性,以沉淀白炭黑、气相白炭黑和甲基MQ树脂,载负荧光指示剂Ru(dpp)₃Cl₂,再填充到二甲基硅橡胶(PDMS)中,制备氧敏感荧光膜.以分光光度计和荧光光谱仪,研究载体种类对Ru(dpp)₃Cl₂的吸附性、荧光特性及氧敏感荧光膜性能的影响.白炭黑载负Ru(dpp)₃Cl₂的荧光发射光谱相对其稀溶液约红移20 nm.载体表面的甲基可减弱SiO₂载体对Ru(dpp)₃Cl₂分子的吸附性和相互作用,减少荧光发射光谱的红移12 nm,提高荧光强度近10倍.白炭黑有助改善Ru(dpp)₃Cl₂在PDMS中的分散性和氧敏感荧光膜的荧光输出和猝灭比,尤以MQ树脂的效果最为显著.     

A Selective and Sensitive "Turn-on" Fluorescent Chemosensor for Recognition of Hg(2+) Ions in Water

Based upon highly selective and irreversible Hg(2+) -promoted deprotection of the dithioacetal reaction, a new water-soluble "turn-on" fluorescent chemosensor (1) was prepared and exhibited high selectivity and sensitivity towards the Hg(2+) ion over other heavy and transition-metal ions in pure water by transforming a weakly fluorescent precursor (colorless) to a highly fluorescent aldehyde (yellow-green; see figure) with a 155-fold increase in fluorescent intensity.     

嵌合异硫氰酸罗丹明B核壳荧光纳米颗粒制备的新方法研究

随着纳米技术的发展,结合了纳米技术与材料制备技术而发展起来的荧光染料嵌合的核壳荧光纳米颗粒的制备为生物医学领域的研究提供了新的材料、技术和方法。何晓晓等以联钉吡啶配合物为核材料,制备了嵌合无机金属配合物的核壳荧光纳米颗粒,段菁华等用异硫氰酸荧光素FITC与蛋白质IgG相结合,     

Fabrication of Novel Reversible Photoswitchable Fluorescent Nanoparticles

Novel photoswitchable fluorescent nanoparticles were fabricated by a facile one-step mini-emulsion polymerization, in which fluorescence resonance energy transfer (FRET) donor, 9,10-diphenylanthracene (DPA), and photoswitchable acceptor, spiropyran derivate, were simultaneously embedded in polymer matrix during the polymerization process. The prepared fluorescent nanoparticles exhibit the typical absorption properties of both DPA dye and spiropyran moiety, indicating that the two chromophores have been incorporated into the polymer nanoparticles. The obtained fluorescent nanoparticles exhibited superior photoswitchable fluorescent performance due to the effective photoinduced interparticle FRET. Moreover, the novel photoswitchable fluorescent nanoparticles also revealed small size (ca. 60 nm), high intensity, relatively fast photoresponsive property and good photoreversibility in aqueous media.     

信号肽功能化二氧化硅纳米颗粒的线粒体靶向作用研究

以N-(p-Maleimidophenyl)isocyanate(PMPI)为交联剂, 将线粒体信号肽分子共价修饰到二氧化硅荧光纳米颗粒表面, 构建线粒体信号肽功能化二氧化硅荧光纳米颗粒. 采用荧光分光光度计、Zeta电位仪以及透射电子显微镜对修饰前后的二氧化硅纳米颗粒进行了表征. 结果表明, 信号肽可被成功修饰在纳米颗粒表面, 并且纳米颗粒粒径在信号肽分子修饰前后没有发生明显变化. 以分离纯化的细胞核作为对照, 采用流式细胞术考察了信号肽功能化二氧化硅荧光纳米颗粒与分离纯化后的线粒体的相互作用. 结果表明, 线粒体信号肽修饰到二氧化硅纳米颗粒表面后依然保持良好的生物活性, 能够介导二氧化硅纳米颗粒特异性识别及结合分离纯化的线粒体, 从而为线粒体监测及其功能调控研究提供了新的思路.     

A unique approach to development of near-infrared fluorescent sensors for in vivo imaging

Near-infrared (NIR) fluorescent sensors have emerged as promising molecular tools for imaging biomolecules in living systems. However, NIR fluorescent sensors are very challenging to be developed. Herein, we describe the discovery of a new class of NIR fluorescent dyes represented by 1a/1c/1e, which are superior to the traditional 7-hydroxycoumarin and fluorescein with both absorption and emission in the NIR region while retaining an optically tunable hydroxyl group. Quantum chemical calculations with the B3LYP exchange functional employing 6-31G(d) basis sets provide insights into the optical property distinctions between 1a/1c/1e and their alkoxy derivatives. The unique optical properties of the new type of fluorescent dyes can be exploited as a useful strategy for development of NIR fluorescent sensors. Employing this strategy, two different types of NIR fluorescent sensors, NIR-H(2)O(2) and NIR-thiol, for H(2)O(2) and thiols, respectively, were constructed. These novel sensors respond to H(2)O(2) or thiols with a large turn-on NIR fluorescence signal upon excitation in the NIR region. Furthermore, NIR-H(2)O(2) and NIR-thiol are capable of imaging endogenously produced H(2)O(2) and thiols, respectively, not only in living cells but also in living mice, demonstrating the value of the new NIR fluorescent sensor design strategy. The new type of NIR dyes presented herein may open up new opportunities for the development of NIR fluorescent sensors based on the hydroxyl functionalized reactive sites for biological imaging applications in living animals.     

氨肽酶N荧光探针的研究进展

氨肽酶N(aminopeptidase N,APN)是一种外肽酶,广泛存在于哺乳动物体内,可从蛋白质多肽链的N末端水解中性或碱性氨基酸,在人体中具有多种重要的生理功能。APN可作为癌症诊断的标志物,尿液中APN也可作为肾小球肾炎的早期生物标志物。本文综述了APN荧光探针的研究进展,主要包括亲和力型APN荧光探针和反应型APN荧光探针,并对它们的优缺点进行了比较;最后对APN荧光探针的发展前景进行了展望。     

Turning fluorescent dyes into Cu(II) nanosensors

There is great interest in the self-organization of the proper subunits as a new strategy for the realization of fluorescent chemosensors. In this article, it is shown that commercially available fluorescent dyes, functionalized with triethoxysilane moieties, can be converted into fluorescent chemosensors by simple inclusion into silica nanostructures. Dye-doped silica nanoparticles and thin films detect Cu(II) ions in the micromolar range by the quenching of fluorescence emission. The different response toward Zn(II), Ni(II), and Co(II) metal ions was also investigated and is reported. The self-organization of the silica structures leads, at the same time, to the formation of metal ion binding sites as well as to the linking of a fluorescent reporter in their proximity. Structural features of the materials, particularly particle size and network porosity, strongly affect their ability to act as fluorescent sensors.     

A proton sponge-based fluorescent switch

A proton-triggered fluorescent switch was developed through direct connection of a proton sponge, 1,8-bis(dimethylamino)naphthalene to a fluorophore, 4-aminonaphthalimide. The molecular fluorescent switch was based on a photoinduced electron transfer (PET) mechanism. The fluorescent switch exhibited significant fluorescence enhancement upon binding the low-concentration protons in high pH aqueous solution. The high pK_a value (around 11) of the fluorescent switch could be ascribed to the nature of the proton sponge.     

荧光碳点探针的合成、性质及其在生物成像中的应用

荧光碳点探针是近几年来发展起来的一种新型荧光探针，具有传统有机染料、荧光染色蛋白及一般荧光纳米材料无法比拟的独特优势，如具有良好的水溶性、化学惰性、低毒性、易于功能化、抗光漂白性、可调谐和生物相容性等优异性能，因而引起研究者的广泛关注。目前已发展水热法等近十种较为经济便捷的方法，可进行大规模的荧光碳点制备，在细胞功能研究及细胞表面和内部功能分子的探测、组织的成像、病菌的定位等方面得到了较为广泛的应用。笔者对近年来荧光碳点的合成方法、依赖于碳点尺寸和波长等性质的发光性能，以及荧光碳点在生物成像等方面的应用作一简要综述，并对其在药用植物病理方面的应用提出展望，期望为丰富荧光碳点在生物成像领域的应用提供一定的借鉴和参考。     

A New ESIPT Fluorescent Dye-Doped Silica Aerogel

Summary: A silyl-functionalized benzazole dye, fluorescent by excited state intramolecular proton transfer (ESIPT) mechanism, was synthesized by reacting 2-(2′-hydroxyphenyl)benzoxazole with 3-(triethoxysilyl)propyl isocyanate. The fluorescent silica gel was prepared by the addition of a solution of 2-propanol and the fluorescent dye after the gelation time. The monolithic aerogel was obtained via supercritical CO₂ drying of the fluorescent gel. The resulting aerogel is transparent in the visible light and fluorescent in the blue-green region under UV radiation.     

Tuning Fluorescent Response of Nanoscale Film With Polymer Grafting

An effective method for tuning fluorescent response of an ultrathin (5 nm) polymer film, which can be used for generation of sensing arrays, is reported. This method is distinctive in that the modification of the optical response is achieved with polymer grafting of a non‐fluorescent polymer to a fluorescent film. Using this approach, a number of films demonstrating different fluorescent emission when exposed to solvent vapors were synthesized.     

Reconstituted low density lipoprotein: a vehicle for the delivery of hydrophobic fluorescent probes to cells.

Previous studies have shown that the cholesteryl ester core of plasma low density lipoprotein (LDL) can be extracted with heptane and replaced with a variety of hydrophobic molecules. In the present report we use this reconstitution technique to incorporate two fluorescent probes, 3-pyrenemethyl-23, 24-dinor-5-cholen-22-oate-3 beta-yl oleate (PMCA oleate) and dioleyl fluorescein, into heptane-extracted LDL. Both fluorescent lipoprotein preparations were shown to be useful probes for visualizing the receptor-mediated endocytosis of LDL in cultured human fibroblasts. When normal fibroblasts were incubated at 37 degrees C with either of the fluorescent LDL preparations, fluorescent granules accumulated in the perinuclear region of the cell. In contrast, fibroblasts from patients with the homozygous form of familial hypercholesterolemia (FH) that lack functional LDL receptors did not accumulate visible fluorescent granules when incubated with the fluorescent reconstituted LDL. A fluorescence-activated cell sorter was used to quantify the fluorescence intensity of individual cells that had been incubated with LDL reconstituted with dioleyl fluorescein. With this technique a population of normal fibroblasts could be distinguished from a population of FH fibroblasts. The current studies demonstrate the feasibility of using fluorescent reconstituted LDL in conjunction with the cell sorter to isolate mutant cells lacking functional LDL receptors.     

A selective fluorescent turn-on NIR probe for cysteine

A selective and sensitive turn-on fluorescent NIR probe for cysteine has been developed. Cleavage of 2,4-dinitrobenzenesulfonyl (DNBS) with thiols switches the weakly fluorescent aza-BODIPY dye (λ(em) = 734 nm, Φ(f) = 0.03) to a strongly fluorescent species in the NIR region (λ(em) = 755 nm, Φ(f) = 0.14).     

Facile Preparation of Bright‐Fluorescent Soft Materials from Small Organic Molecules

Highly fluorescent and biocompatible soft materials are desirable for many potential applications, but their synthetic processes are somehow complicated. Herein, we have explored the feasibility of synthesis of unconventional fluorescence soft materials from small organic molecules under mild conditions. A new blue‐fluorescent soft material with high quantum yield (89.6 %) and eutectic feature prepared by simple heat treatment of citric acid (CA) and cysteine (Cys) aqueous mixtures below 100 °C in air was reported. The as‐prepared fluorescent material has the features of facile preparation, low cost, scalable production and easy to process, making it suitable for applications like fluorescent labeling and light‐emitting devices. This new finding opens a new venue for the preparation of fluorescent soft materials.