Polymer-based fluorescence sensor incorporating triazole moieties for Hg detection via click reaction

The polymer could be obtained by the polymerization of 1,4-dibutoxy-2,5-diethynylbenzene (M-1) with 1,4-diazidobenzene (M-2)via click reaction. The polymer show blue fluorescence. The responsive optical properties of the polymer on various transition metal ions were investigated by fluorescence spectra. Compared with other cations, such as Co²⁺, Ni²⁺, Ag⁺, Cd²⁺, Cu²⁺ and Zn²⁺, Hg²⁺ can exhibit the most pronounced fluorescence response of the polymer Hg²⁺ can exhibit the most pronounced fluorescence response of the polymer due to triazole moiety in the polymer main chain as the metal binding ligand. The results indicate this kind of conjugated polymer with triazole moiety synthesized by click reaction can be used as a selective fluorescence sensor for Hg²⁺ detection.     

一种罗丹明类Hg~(2+)和pH双功能荧光探针及其选择识别性能

以罗丹明B、水合肼和对羟基苯甲醛为原料,合成了一种新型的荧光增强型识别Hg2+和pH双功能荧光探针,即对羟基苯甲醛罗丹明B腙(HRBH)。用FT IR、1 H NMR和13 C NMR对其分子结构进行了表征,并通过荧光光谱对探针的识别性能进行了研究。研究结果表明:当N,N-二甲基甲酰胺(DMF)为溶剂时,探针HRBH对Hg2+具有良好的选择识别性,并且基本不受其他金属离子的影响;通过Job’s曲线可知,探针与Hg2+的配合比为1∶1;Hg2+浓度在3×10-5~7×10-5 mol/L的范围内,探针HRBH的荧光强度与Hg2+浓度呈现出较好的线性关系,线性相关系数为0.9903;探针对pH值的响应区间为3~6,并具有良好的可逆性。     

罗丹明类荧光探针的合成及其对Hg~(2+)的识别研究

以罗丹明B、水合肼及2'-羟基苯乙酮等廉价化合物为原料,经过简单的缩合反应得到可识别Hg~(2+)的荧光探针L,其结构经1HNMR、13CNMR以及HR-MS表征。光谱性能研究表明,探针L在Et OH-H2O(V(Et OH)∶V(H2O)=4∶1,p H 7.0,20 mmol/L HEPES)体系中,对Hg~(2+)具有优异的识别能力,两者的配合比为1∶1,且识别过程可逆。     

A novel polymer chemodosimeter for the detection of mercury ions: Synthesis and fluorescence “turn‐on” responses of fluorene‐based conjugated polymer with reactive pendent N,N‐diethyl‐2‐(4‐phenoxy)‐thioacetamide

A novel conjugating polyfluorene bearing N,N‐diethyl‐2‐(4‐phenoxy)‐thioacetamide as side chain was designed for the detection of Hg(II) ions. It was synthesized through postfunctionalization of acetamide‐based polyfluorene derivative. Upon the addition of Hg(II) ions, the thioacetamide groups of this polymer side chains were specifically reacted with Hg(II) ions, leading to this chemodosimeter with higher selectivity for Hg(II) over other metal ions tested under the same conditions. In addition, on the basis of the effect of fluorescent signal amplifications originated from electron transmission along the backbone, this designed conjugated polyfluorene with pendent reactive thioacetamide reached ultra high sensitivity for the detection of mercury ions. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

SiO2/还原氧化石墨烯复合材料的简易制备及对罗丹明B的吸附

以正硅酸乙酯（TEOS）为硅源,氧化石墨烯（GO）为载体,在不添加任何还原剂的情况下,通过水热法简易制备SiO₂/还原氧化石墨烯（SiO₂/RGO）复合材料。采用TEM、FTIR、XRD、TG-DSC、N₂-吸附对复合材料的微观结构进行表征,分析表明：负载量为76.60%（质量分数）的SiO₂纳米颗粒均匀分散在RGO表面上,且部分以Si-O-C键进行配位;具有多级孔结构的SiO₂/RGO复合材料孔径主要分布在1~7nm,比表面积高达676m²/g。以罗丹明B为目标污染物,考察了pH、投入量、温度和接触时间等因素对复合材料吸附性能的影响,结果表明：在pH为2、35℃时,复合材料具有最佳的吸附效果,吸附量为127.8mg/g。动力学分析表明吸附过程符合准二级动力学模型,热力学参数揭示吸附过程为自发吸热过程。     

Removal of Hg2+ from aqueous solution using a novel composite carbon adsorbent

A novel composite carbon adsorbent (GCA) has been prepared by immobilizing activated carbon and genipin‐crosslinked chitosan into calcium alginate gel beads via entrapment and applied to the removal of mercury (Hg²⁺) ions from aqueous solution (e.g., drinking water). Two bead sizes and two mixing ratios of components were obtained and characterized. Batch experiments were performed to study the uptake equilibrium and kinetics of Hg²⁺ ions by the GCA. The Hg²⁺ adsorption capacity of GCA was found to be dependent of pH and independent of size of the adsorbent. The Hg²⁺ adsorption rate of GCA increases with decreasing its bead size. However, both adsorption capacity and rate of GCA for Hg²⁺ increase with increasing its chitosan content. Otherwise, it was shown that the GCA has higher Hg²⁺ adsorption capacity and rate than activated carbon, which might be caused by the incorporation of chitosan into the GCA. The maximum Hg²⁺ adsorption capacity of GCA was found to be 576 mg/g, which is over seven times higher than that of activated carbon. Our results reveal the uniform distribution of activated carbon and chitosan within the alginate gel bead and that Hg²⁺ ions can diffuse inside the bead. It also demonstrated the feasibility of using this GCA for Hg²⁺ removal at low pH values. The Hg²⁺ absorbed beads of the GCA can be effectively regenerated and reused using H₂SO₄. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis of 3,3‐Disubstituted Oxindoles Containing a 3‐(4‐Aminobut‐2‐ynyl) Unit via Domino Heck–Sonogashira Reaction in Water

In this study, palladium‐catalyzed domino Heck–Sonogashira reactions have been developed in water. Using this strategy, a series of 3‐(4‐aminobut‐2‐ynyl)oxindole derivatives with an all‐carbon quaternary center at the 3‐position were easily synthesized. The reactions provided products in excellent yields with a broad substrate tolerance. The target product was readily converted into a pharmaceutically active molecule, which is used as a 5‐HT₇ receptor antagonist.

     

纳米锐钛型TiO2催化超声降解罗丹明B的研究

研究了不同条件下TiO_2催化超声降解有机染料罗丹明B条件和相关机理。该反应为一级动力学反应,其常数为:0.0171min～1;初始浓度从0增加到10mg/L时降解率增加,超过10mg/L时降解率开始下降;当催化剂浓度为1000mg/L降解率达到最大。研究结果表明:在pH=5、初始浓度为10mg/L、催化剂浓度为1000mg/L、超声功率50W、超声频率40kHz,体系温度为20℃时,经100分钟,罗丹明B的降解率达到83.7%。     

罗丹明B衍生物荧光探针的合成及其对Fe3 的检测

以罗丹明B与苯胺为原料,经过缩合反应制得一种罗丹明B衍生物的荧光探针F-1[3',6'-二(二乙基氨基)-2-苯基螺[异吲哚-3,9'-氧杂蒽]-1-酮],其结构通过1HNMR、13CNMR、红外光谱和高分辨质谱(HRMS)进行确证。Fe~(3+)加入探针体系后,体系颜色由无色变为紫色,荧光显著增强,而不受其他金属离子(Na~+、K~+、Ca~(2+)、Mg~(2+)、Zn~(2+)、Hg~(2+)、Co~(2+)、Cd~(2+)、Ni~(2+)、Cu~(2+)、Mn~(2+)、Ag+、Pb~(2+)、Cr~(3+)、Fe~(2+))干扰。通过测定探针化合物F-1的离子选择性、离子竞争性、浓度梯度、Job’s曲线和pH对探针分子荧光强度的影响,发现在p H=5～7的环境中,Fe~(3+)浓度在2.0×10~(–6)～1.8×10~(–5) mol/L时,探针F-1对其检测呈较好的线性关系,其具备定性、定量检测生物机体或者环境中痕量Fe~(3+)的潜力。     

B4C-based hard and tough ceramics densified via spark plasma sintering using a novel Mg2Si sintering aid

Full-dense B₄C-based ceramics with excellent mechanical properties were fabricated using spark plasma sintering with Mg₂Si as a sintering aid at a low temperature of 1675 °C while applying a uniaxial pressure of 50 MPa. The effect of Mg₂Si addition on the densification behaviours, mechanical properties and microstructure of as-sintered ceramics were investigated. Not only did the formation of ultra-fine grained SiC using the in-situ reaction effectively inhibit the growth of B₄C grains, but it also contributed to the strength and toughness of the resultant ceramics. Additionally, microalloying Mg imparted more metal bonding characteristics to the B₄C matrix, thereby improving their ductility. The results indicate that the composite containing 7 wt% Mg₂Si had excellent mechanical properties, including a light weight of 2.54 g/cm³, Vickers hardness of 34.3 GPa, fracture toughness of 5.09 MPa m^1/2 and flexural strength of 574 MPa.     

Adsorption of Hg2+ on a novel chelating fiber prepared by preirradiation grafting and amination

A novel chelating fiber was prepared by the irradiation‐induced grafting copolymerization of glycidyl methacrylate on polypropylene fiber and consequent amination with diethylenetriamine. The effects of the reaction conditions, such as reaction time, temperature, and monomer concentration, on the degree of grafting were investigated. The optimal conditions for grafting were found to be 3 h, 100°C, and a 50% (v/v) glycidyl methacrylate concentration in tetrahydrofuran solution. This fiber showed good adsorption performance at different concentrations of Hg²⁺, in particular for trace Hg²⁺. Under the adsorption conditions of pH = 4, initial concentration = 1000 mg/L, and time = 20 h, the adsorption capacity of the chelating fiber for Hg²⁺ reached 785.28 mg/g. It completely adsorbed the Hg²⁺ ions in solution within a short contact time, showing a very high adsorption rate for Hg²⁺. Furthermore, the chelating fiber also had a high selectivity for mercury, whereas Cu²⁺ coexisted in different concentrations. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Efficient Preparation of the Isoindoline Framework via a Six Component,Tandem Double A3‐Coupling and [2+2+2] Cycloaddition Reaction

The preparation of tetrasubstituted isoindolines from three alkyne units, two aldehyde units and a primary amine via three consecutive reactions, two aldehyde‐amine‐alkyne couplings (A³‐couplings) and a final [2+2+2] cycloaddition, in a single synthetic operation, is described. The A³‐couplings are catalyzed by copper bromide and the cycloaddition is catalyzed by Wilkinson’s catalyst. It was found that many catalysts known to be efficient at the cycloaddition step were not suitable when this step was part of the tandem reaction sequence. Wilkinson’s catalyst was found to be unique in its suitability for the overall domino reaction sequence.     

新型狂犬病病毒中和抗体检测方法的建立

目的建立一种安全、快速、经济的新型狂犬病病毒中和抗体的检测方法。方法在狂犬病病毒弱毒株HEP-Flury基因组Ψ区插入增强型绿色荧光蛋白(enhanced green fluorescent protein eGFP)基因,利用反向遗传技术,拯救重组病毒rHEP-eGFP,分别采用荧光显微镜观察、直接免疫荧光染色鉴定及电镜观察等方法对rHEP-eGFP病毒进行鉴定;分别绘制rHEP-eGFP和亲本毒株HEP-Flury的生长动力学曲线;将rHEP-eGFP在BHK-21细胞中连续传代9次,测定各代次rHEP-eGFP的滴度,荧光显微镜下观察eGFP的表达;采用TCID50法检测狂犬病病毒标准攻击毒株CVS-11和rHEP-eGFP的毒力;以rHEP-eGFP病毒为抗原,建立新型荧光抗体病毒中和试验(fluorescent antibodyvirus neutralization,FAVN)-eGFP,对25份犬血清的抗体效价进行测定,并与标准FAVN检测结果进行比较。结果经荧光显微镜观察、直接免疫荧光染色鉴定和电镜观察表明,成功拯救出rHEP-eGFP病毒;重组病毒rHEP-eGFP与亲本病毒HEP-Flury的生长特性相似;rHEP-eGFP连续传代9次,均能稳定表达eGFP;CVS-11的毒力为108TCID50/ml,rHEP-eGFP的毒力为107.3TCID50/ml;FAVN-eGFP与FAVN测定25份犬血清抗体效价的结果具有良好的一致性。结论建立的新型狂犬病病毒中和抗体检测方法(FAVN-eGFP)准确度高,特异性好。     

Dual-emission carbon dots-copper nanoclusters ratiometric photoluminescent nano-composites for highly sensitive and selective detection of Hg2+

A novel dual-emission photoluminescent (PL) nano-materials of carbon dots-copper nanoclusters (CDs-CuNCs) nano-composites is prepared for excellent sensitivity and selectivity toward Hg²⁺. The nano-composites are composed of blue photoluminescent CDs and red photoluminescent CuNCs with similar excitation wavelengths through the electrostatic assembly. The red photoluminescence of CuNCs was inhibited by the nano-composites exposed to Hg²⁺, while the blue photoluminescence of CDs remained stable. The color of the nano-composites slowly changed from pink to blue with the added of Hg²⁺ concentration. The limit of detection (LOD) of the nano-composites is 0.31 nmol/L (nM) toward Hg²⁺ in aqueous solution, when the signal to noise ratio is 3. In addition, a visual PL test paper is prepared. When the Hg²⁺ solution is added, the color of test paper transforms from pink to blue immediately. Therefore, the nano-composites are very important for efficient and sensitive detection of Hg²⁺, which show broad application prospects in environmental analysis, food safety detection, biological detection and medical diagnosis in daily life.     

Fabrication of TaB2/mullite composites by combustion synthesis with excess silicon and B2O3 additions

Preparation of TaB₂/mullite composites from a cost- and energy-effective mixture of reactants was conducted by self-propagating high-temperature synthesis (SHS). The sample stoichiometry of 1.18Ta₂O₅+(2.36x)B₂O₃+6Al+(2y)Si was formulated with x=1.0–1.3 and y=1.0–2.0 for the study of the effects of excess B₂O₃ (x>1.0) and Si (y>1.0) on combustion characteristics and product compositions. The synthesis reaction involved coreduction of Ta₂O₅ and B₂O₃ by Al and Si. The reaction exothermicity and combustion velocity increased slightly with increasing B₂O₃ but decreased considerably with Si. Formation of TaB₂ and mullite was improved by adopting excess B₂O₃ and Si to compensate for their evaporation loss at high combustion temperatures up to about 1600 °C. The sample with x=1.3 and y=1.5 was shown to yield the optimum formation of TaB₂ and mullite. Mullite grains with a tubing-like shape were produced from in situ formed SiO₂ and Al₂O₃ and had an atomic composition close to that of 3:2 mullite (3Al₂O₃·2SiO₂).     

Preparation of a novel chelating resin bearing amidinothiourea moieties and its removal properties for Hg(II) ions in aqueous solution

A novel chelating resin bearing amidinothiourea (ADTU) moieties was prepared by chloroethyl crosslinked polystyrene (CMPS) with ADTU in the presence of a phase transfer catalyst. Fourier transform infrared spectra (FT-IR) and scanning electron microscopy (SEM) were used to characterized the resulting chelating resin. The saturated adsorption capacity of Hg(II) ions estimated from the Langmuir model was up to 1215 mg g^?1at 313 K. Furthermore, the resin was able to selectively separate Hg(II) from multicomponent solutions with Cd(II), Co(II), Cu(II), Zn(II), Mg(II) and Pb(II). The desorption process showed the mercury recovery reached to 99.2% under eluting condition of 1 M HCl + 8% thiourea.     

Oligomeric A2 + B3 synthesis of highly branched polysulfone ionomers: novel candidates for ionic polymer transducers

Highly branched poly(arylene ether sulfone)s with systematically varied degrees of branching and sulfonation were synthesized through oligomeric A₂ + B₃ methods for application as ionic polymer transducer (IPT) membranes. IPTs are a class of electroactive polymer devices that leverage ionomeric membranes to perform electromechanical transduction as actuators and/or sensors. Synthesis of controlled molecular weight A₂ oligomeric polysulfones targeted the global degree of branching (DB_global) to approximately 1–3% in the absence of gelation. Size exclusion chromatography confirmed molecular weights greater than 20 000 g mol^?1 were achieved for linear and branched polysulfones. Increased degree of sulfonation of the A₂ oligomers reduced the development of molecular weight in the oligomeric A₂ + B₃ branching reaction; the formation of tough, flexible, ion‐conducting membranes is required for emerging transducer applications. Variation in the DB_global attained did not affect the thermal transitions or elastic modulus as significantly as changes in the degree of sulfonation. However, an ionic dissociation temperature was detected below the glass transition temperature of the polysulfone matrix and was relatively independent of the degree of sulfonation. Successful synthesis and characterization of these well‐defined branched polysulfone ionomers provide a basis for future investigation of polymer topology effects on IPT performance. Copyright © 2009 Society of Chemical Industry     

罗丹明B类Cu~(2+)荧光增强型探针的合成及其选择性识别

设计并合成了一种可用于识别的Cu~(2+)新型荧光探针(3',6'-双(二乙氨基)-2-(4-(二乙氨基)-2-羟基苯胺基-螺(异喹啉-1,9'-氧杂蒽)-3-酮)(RB)。通过红外、元素分析、质谱、~1HNMR、~(13)CNMR等手段表征了探针的结构。其光谱性和离子选择性实验结果表明,RB自身荧光很弱,但是与Cu~(2+)结合后会发生显著的荧光增强,而与其他金属离子结合后,荧光强度变化很小。说明RB对Cu~(2+)具有很好的选择性和较高的灵敏度,可用作Cu~(2+)荧光增强型探针,据此建立了一种测定Cu~(2+)的新型分析方法。     

Analysis of fluorescence properties of novel Eu3+-doped ZnAl2O4-based ceramic aerogels for high-power optical device applications

A novel series of ZnAl₂O₄:Eu³⁺ aerogels (ZAE) and mullite ceramic phase reinforced ZnAl₂O₄:Eu³⁺ aerogels (MZAE) with high fluorescence thermal stability have been firstly synthesized for the encapsulation of high-power optical devices. However, due to the intrinsic structural brittleness of the aerogel, the structure of ZAE tends to collapse during the heat treatment and the fluorescence performance falls short of expectations. To this end, we propose a simple and effective strategy to enhance the structural rigidity of fluorescent aerogels by introducing the mullite ceramic phase into the network structure of ZAE. This can effectively suppress the agglomeration of Eu³⁺ caused by the collapse of the structure during the heat treatment, thus enhancing the optical properties of the aerogel. Compared with ZAE, MZAE has higher fluorescence thermal stability. The fluorescence intensity of MZAE at 498 K is still 75 % of that at 298 K, and the chromaticity shift is only 22 × 10⁻³.