5-氯-3-硝基螺吡喃的合成及对银离子和有机胺的识别

合成并研究了5-氯-3-硝基螺吡喃光谱性质及特异性识别.研究结果表明,5-氯-3-硝基螺吡喃具有溶剂化显色效应,闭环结构SP和开环结构MC分别在非极性和极性溶剂中稳定存在;该螺吡喃能从18种常见金属离子中特异识别出Ag+,且可识别四类共16种有机胺.     

吲哚啉螺吡喃的合成及其光致变色性质研究

从小分子出发通过一系列的合成步骤,最终合成了3,3-二甲基-N-乙基-6’-硝基苯并螺吡喃(SP1)、3,3-二甲基-N-乙基-5-氯-6’-硝基苯并螺吡喃(SP2)和3,3-二甲基-N-乙基-5-甲氧基-6’-硝基苯并螺吡喃(SP3)3种未见文献报道的螺吡喃。通过元素分析、红外光谱、核磁共振等手段对合成的部分中间体和目标产物的结构进行表征,并应用紫外-可见吸收光谱对其光致变色性进行了研究。     

基于苯并噻唑类螺吡喃检测三价金属离子铁、铬、铝的比色和荧光化学传感器

合成了新型苯并噻唑类的螺吡喃化合物3-苄基-8′-甲氧基-6′-硝基-3H-螺[苯并[d]噻唑-2,2′-苯并吡喃]即SP,其可以作为比色和荧光化学传感器,用来检测溶液中的三价金属离子铁、铬和铝。由于苯并噻唑类螺吡喃化合物特殊的结构与性能,在不同的光照条件下此化合物SP可以作为重要的光响应分子。采用紫外-可见分光光度计、荧光-分光光度计、傅里叶红外光谱仪和核磁共振仪分析了化合物的性能。结果表明:此化合物具有良好的裸眼识别效果、紫外和荧光识别效果,良好的抗干扰性,较快的响应时间和较低的检测限等优点。     

一种光响应SP-COOH/PAN纤维膜材料的制备及调节湿度的研究

通过物理掺杂将N-羧基螺吡喃(SP-COOH)与聚丙烯腈(PAN)混合,并利用静电纺丝技术制备了一种新型光响应调节湿度的SP-COOH/PAN纤维膜材料。利用螺吡喃的光致异构化的特性,使电纺薄膜的润湿性和周围湿度可以通过紫外-可见光的交替照射来可逆地调节。在紫外光照射下,会使螺C-O键断裂,此时螺吡喃分子呈现开环的、有颜色的极性分子,与水分子容易形成静电吸引;而在可见光照射下,螺C-O键重新结合,此时呈现了一种闭环的、无色的非极性分子,与水分子的吸引减弱。通过这种功能分子极性的变化可以可逆的操纵材料表面的润湿性,进而应用于周围环境湿度的调节。研究结果表明,在紫外-可见光交替照射下纤维膜表面的润湿性的变化范围和对周围湿度的调节范围呈现正向关系,并均随着SP-COOH的掺杂量增多而变大,当SP-COOH的掺杂量为10%时,材料表面润湿性可变化约16°,湿度调节范围约为±6%。另外,静电纺丝技术是一种简单、易操作、可实现大面积生产的制备膜的方法,这些优点有利于该类膜材料应用于实际生活。     

光致变色材料的研究与应用

变色材料在变色眼镜、光学信息存储、光分子开关等方面具有广泛的应用.主要分析了螺吡喃、俘精酸酐、二芳基乙烯以及二氧化钛、卤化银等有机和无机光致变色材料的研究现状及其变色机理,最后介绍了光致变色材料在国防以及信息存储材料等方面的应用前景.     

新型胶原/聚丙烯酸互穿网络pH敏感水凝胶的制备及性能研究

以Bis为交联剂,采用互穿网络(IPN)技术制备胶原/聚丙烯酸pH敏感水凝胶.研究了不同配比的水凝胶的溶胀动力学、pH敏感性及pH溶胀-退胀特性,并利用傅里叶变换红外光谱法(FTIR)和差示量热扫描法(DSC)对其结构进行表征.结果显示:制备的水凝胶具有较快的溶胀速率,在13min时吸水率可达93%左右;水凝胶有明显的pH敏感性且pH溶胀-退胀可逆性良好.FTIR和DSC结果表明,在保持胶原三股螺旋结构的同时,材料间形成了互穿网络,材料的热稳定性显著提高,从而扩大了材料的应用范围.     

多孔有机聚合物在传感领域中的研究进展

多孔有机聚合物(POPs)是由轻质元素(C、H、O、N、B等)通过较强的共价键相互连接而形成的一类二维或三维多孔网状结构的多孔材料。其由于具有较大的比表面积，丰富的孔隙结构，极高的孔隙率，物理化学稳定性，以及易于功能化等特性，近年来人们在传感器应用领域中进行了较为深入的研发。总结了近年来各种POPs在气体传感、金属离子传感、爆炸物传感、药物传感、生物传感等领域的研究进展，并探讨了未来的技术发展方向与前途。     

壳聚糖/硫化锰纳米复合膜传感碘离子性能研究

利用壳聚糖(CS)易于成膜的特点,在有机物调制的条件下,通过异相成核生长制备了CS/硫化锰(MnS)纳米复合膜。研究了成膜条件对膜的水热稳定性和发光性能的影响,以及CS/MnS纳米复合膜对响应物的影响特征。通过荧光性能探索CS/MnS纳米复合膜的传感性能,研究结果表明,在水体系中除碘离子外,其他常见的离子对薄膜荧光发射没有显著影响,而CS/MnS纳米复合膜的荧光强度随着碘离子的浓度(0~5.40×10-4 mg/L)的增加而降低,荧光强度从388到204。但是荧光光谱的形状以及最大波长的位置不变。通过对其可逆性的测定,发现复合膜的可逆性很强,预期CS/MnS纳米复合膜有可能发展成为检测碘离子的一种重要的专用传感膜材料。     

自乳化法制备光致变色微球

以甲基丙烯酸甲酯、丙烯酸正丁酯、丙烯酸等为单体,二丙烯酸-1,6-己二醇酯为交联剂,采用自乳化法制备了丙烯酸酯乳液。乳液的平均粒径为249nm,具有较好的单分散性。用该乳液对自制的光致变色材料螺吡喃进行包裹,获得了光致变色微球。在常温下,采用紫外-可见光谱对光致变色微球的变色性质及抗疲劳性进行了检测,并通过建立半数吸光度可逆变色循环次数参数Z50,将包裹了螺吡喃的微球与未包裹的螺吡喃溶液进行对比,发现包裹后的微球除了具备良好的光致变色性质外,其抗疲劳性亦远高于其溶液。     

双羟基螺吡喃的合成及其光致变色性能研究

以2-羟基-3-甲氧基苯甲醛为原料,在制得2,3-二羟基-5-硝基苯甲醛的基础上,将其同2,3,3-三甲基-N-羟乙基-3H吲哚溴化物反应,合成了双羟基螺吡喃化合物。研究了制得化合物的光致变色性能。结果发现,0.02g/L的双羟基螺吡喃乙醇溶液,最大吸收波长在559nm,随紫外光照时间延长,溶液的吸光度逐渐增加,光照时间超过480s后,变化不明显;撤去紫外灯后,在日光灯照射下,双羟基螺吡喃乙醇溶液颜色逐渐恢复,超过600s后溶液颜色几乎变回原色;不同pH条件下,双羟基螺吡喃乙醇溶液经365nm紫外光照射后,呈现出不同的颜色。     

Characterization of ligand-functionalized microcantilevers for metal ion sensing

A sensor for metal cations is demonstrated using single and binary mixtures of different thiolated ligands as self-assembled monolayers (SAMs) functionalized on silicon microcantilevers (MCs) with gold nanostructured surfaces. Binding of charged metal ions to the active surface of a cantilever induces an apparent surface stress, thereby causing static bending of the MC that is detected in this work by a beam-bending technique. A MC response mechanism based on changes in surface charge is discussed. The monodentated ligands arranged as SAMs on the MC surface are not expected to fully satisfy the coordination sphere of the detected metals. This leads to lower binding constants than would be expected for chelating ligands, but reversible responses. The modest binding constants are compensated in terms of the magnitudes of responses by the inherent higher sensitivity of the nanostructured approach as opposed to more traditional smooth surface MCs. Response characteristics are optimized in terms of SAM formation time, concentration of ligand solution, and pH of working buffer solution. Limits of detection for the tested mono-, di-, and trivalent metal ions are in low to submicromolar range. The results indicated that shapes and magnitudes of response profiles are characteristics of the metal ions and type of SAM. The response factors for a given SAM with the tested metal ions, or for a given metal with the tested SAMs, varied by roughly 1 order of magnitude. While the observed selectivity is not large, it is anticipated that sufficient ionic recognition contrast is available for selective metal ion identification when differentially functionalized arrays of MCs (different ligands on different cantilevers in the array) are used in conjunction with pattern recognition techniques.     

Monte Carlo backscattering yield (BY) calculations applying continuous slowing down approximation (CSDA) and experimental data

The backscattering yield (BY) is an important factor in elastic peak electron spectroscopy. Monte Carlo (MC) algorithm describing the electron elastic and inelastic backscattering from surfaces is presented applying the continuous slowing down approximation, i.e., an assumption that an electron loses energy continuously along the trajectory length. Energy losses calculations were performed using recently published stopping power (SP) functions, calculated from the experimental optical data by Tanuma et al., and the experimental SP functions published elsewhere. In the MC algorithm, calculating the values of BY, the input parameters are the elastic scattering cross sections and the SP function. The MC calculations were performed at selected energies ranging from 200 to 30 000 eV. Ten elemental solids were considered: Al, Si, Cr, Ni, Cu, Ge, Pd, Ag, Pt, and Au. All MC simulations were performed for normal incidence of the beam on a sample and the backscattered electron emission into negative hemisphere. Results of BY calculations were compared to available experimental data taken from Joy database of electron-solid interactions. In most cases, the results deviate less than 10% from the available experimental data.     

Insulin-coated gold nanoparticles: a plasmonic device for studying metal-protein interactions

Insulin-capped gold nanoparticles (Au@insulin NPs) are highly sensitive towards pH and heavy metals, due to the protein coating. Au@insulin NPs aggregate and disaggregate reversibly with pH and in the presence of various heavy metal ions, which can be monitored through reversible changes in their optical properties. The sensitivity of the NPs towards different metal ions is dissimilar and depends on the coordinative properties of each specific metal ion, its valence number, concentration, and reaction time (kinetics), representing a simple tool for studying fundamental metal-protein interactions. Moreover, Au@insulin NPs are biocompatible and highly stable at high ionic strengths, due to their robust protein coating.     

飞秒激光空间选择性诱导玻璃微结构及应用

利用飞秒激光与玻璃的非线性相互作用，可以对玻璃进行空间选择性微观改性与修饰，赋予新的光功能．本文介绍飞秒激光的持点及其对玻璃微结构的改性，以及近年来利用飞秒激光进行玻璃的缺陷控制、光活性离子(稀土、过渡和重金属离子)价态操作、微晶析出与折射率调控及其在光开关、波分复用、波导型有源器件、光子晶体等微光学器件的制备及光学集成领域应用的进展．     

Fluorogenic Zn(II) and chromogenic Fe(II) sensors based on terpyridine-substituted tetraphenylethenes with aggregation-induced emission characteristics

Terpyridine-containing tetraphenylethenes (TPEs) are synthesized and their optical and metal sensing properties are investigated. They are practically nonluminescent in the solution state but become highly emissive as nanoparticle suspensions in poor solvents or thin films in the solid state, demonstrating a novel phenomenon of aggregation-induced emission (AIE). The emission of the nanoaggregates of TPEs is pH-sensitive: it is decreased and eventually quenched upon protonation of their terpyridine units because of their AIE nature. The TPEs can work as "turn-off" fluorescent chemosensors for metal ions and display different fluorescence responses to various metal ions. A characteristic red shift in the emission spectra is observed in the presence of Zn(2+), which facilitates the discrimination of Zn(2+) from other metal ions. Because of the metal-to-ligand-charge-transfer process, terpyridine-substituted TPEs display an obvious magenta color upon selectively binding with Fe(2+), allowing a rapid identification of Fe(2+) in the aqueous media by naked eyes.     

Coupling fiber optics to a permeation liquid membrane for heavy metal sensor development

We present the first sensing system for metal ions based on the combination of separation/preconcentration by a permeation liquid membrane (PLM) and fluorescence detection with an optical fiber. As a model, a system for the detection of Cu(II) ions was developed. The wall of a polypropylene hollow fiber serves as support for the permeable liquid membrane. The lumen of the fiber contains the strip solution in which Cu(II) is accumulated. Calcein, a fluorochromic dye, acts as stripping agent and at the same time as metal indicator. The quenching of the calcein fluorescence upon metal accumulation in the strip phase is detected with a multimode optical fiber, which is incorporated into the lumen. Fluorescence is excited with a blue LED and detected with a photon counter. Taking advantage of the high selectivity and sensitivity of PLM preconcentration, a detection limit for Cu(II) of approximately 50 nM was achieved. Among five tested heavy metal ions, Pb(II) was the only major interfering species. The incorporation of small silica optical fibers into the polypropylene capillary allows for real-time monitoring of the Cu(II) accumulation process.     

Controlling Plasmon‐Enhanced Fluorescence via Intersystem Crossing in Photoswitchable Molecules

By harnessing photoswitchable intersystem crossing (ISC) in spiropyran (SP) molecules, active control of plasmon‐enhanced fluorescence in the hybrid systems of SP molecules and plasmonic nanostructures is achieved. Specifically, SP‐derived merocyanine (MC) molecules formed by photochemical ring‐opening reaction display efficient ISC due to their zwitterionic character. In contrast, ISC in quinoidal MC molecules formed by thermal ring‐opening reaction is negligible. The high ISC rate can improve fluorescence quantum yield of the plasmon‐modified spontaneous emission, only when the plasmonic electromagnetic field enhancement is sufficiently high. Along this line, extensive photomodulation of fluorescence is demonstrated by switching the ISC in MC molecules at Au nanoparticle aggregates, where strongly enhanced plasmonic hot spots exist. The ISC‐mediated plasmon‐enhanced fluorescence represents a new approach toward controlling the spontaneous emission of fluorophores near plasmonic nanostructures, which expands the applications of active molecular plasmonics in information processing, biosensing, and bioimaging.     

Metal ion effects on different types of cell line,metal ion incorporation into L929 and MC3T3-E1 cells,and activation of macrophage-like J774.1 cells

V ions showed high cytotoxicity for mouse fibroblast L929, osteoblastic MC3T3-E1, and macrophage-like J774.1 cells compared with Pb, Cu, Ni, Co, Zn, and Mo ions. The quantities of metal ions incorporated into the L929 and MC3T3-E1 cells increased with increasing metal concentration in the medium, depending on the metal ion type. In particular, the quantities of V incorporated into the cells were markedly higher than those of other metals. It was suggested that the cytotoxicity of a metal ion changes with the quantity of the metal ion incorporated into cells. It was also considered that V ions are incorporated into cells through xanthine derived from fetal bovine serum by high-performance liquid chromatography (HPLC). The strong interaction of Co, Ni and Mo with amino acids was analyzed by HPLC. The rate of increase of nitric oxide (NO) concentration released with the activation of the mouse macrophage-like J774.1 cells increased at a concentration of V ions ten times lower than that of Ni ions. The release of the cytokine tumor necrosis factor-α (TNF-α) from the J774.1 cells started at approximately 0.5 ppm V; interleukin-6 (IL-6) and transforming growth factor-β (TGF-β) showed a marked increase in the rate of increase at more than 1 ppm V. No increase in the concentration of IL-1α, IL-8, IL-15 or granulocyte macrophage-colony stimulating factor (GM-CSF) was observed for V and Ni ions.     

Surface‐Plasmon‐Enhanced Perovskite Light‐Emitting Diodes

Perovskite light‐emitting diodes (PeLEDs) have attracted considerable attention because of their potential in display and lighting applications. To promote commercialization of PeLEDs, it is important to improve the external quantum efficiency of the devices, which depends on their internal quantum efficiency (IQE) and light extraction efficiency. Optical simulations have revealed that 20–50% of the light generated in the device will be lost to surface plasmon (SP) modes formed in the metal/dielectric interfaces. Therefore, extracting the optical energy in SP modes to the air will greatly increase the light extraction efficiency of PeLEDs. In addition, the SPs can accelerate radiative recombination of the emitter via near‐field effects. Thus, the IQE of a PeLED can also be enhanced by SP manipulation. In this review, first, general concepts of the SPs and how they can enhance the efficiency of LEDs are introduced. Then recent progresses in SP‐enhanced emission of perovskite films and LEDs are systematically reviewed. After that, the challenges and opportunities of the SP‐enhanced PeLEDs are shown, followed by an outlook of further development of the SPs in perovskite optoelectronic devices.     

Optical metal ion sensor based on diffusion followed by an immobilizing reaction. Quantitative analysis by a mesoporous monolith containing functional groups

A new optical metal ion sensor based on diffusion followed by an immobilizing reaction has been developed. The current sensor is based on a model that unifies two fundamental processes which a metal analyte undergoes when it is exposed to a porous, ligand-grafted monolith: (a) diffusion of metal ions to the binding sites and (b) metal-ligand (ML(n)) complexation. A slow diffusion of the metal ions is followed by their fast immobilizing reaction with the ligands in the monolith to give a complex. Inside the region where the ligands have been saturated, the diffusion of the metal ions reaches a steady state with a constant external metal ion concentration (C(0)). If the complex ML(n) could be observed spectroscopically, the absorbance of the product A(p) follows: A(p) = Kt(1/2), K = 2epsilon(p)(L(0)C(0)D)(1/2). D = diffusion constant of the metal ions inside the porous solid; L(0) = concentration of the ligands grafted in the monolith; and t = time. This equation is straightforward to use, and the K vs C(0)(1/2) plot provides the correlations with the concentrations (C(0)) of the metal ions. This is a rare optical sensor for quantitative metal ion analysis. The use of the model in a mesoporous sol-gel monolith containing grafted amine ligands for quantitative Cu(2+) sensing is demonstrated. This model may also be used in other chemical sensors that depend on diffusion of analytes followed by immobilizing reactions in porous sensors containing grafted/encapsulated functional groups/molecules.