Pyrazole-Triazine Conjugate as Highly Selective and Sensitive Fluorescence Probe for Silver (Ⅰ) Detection and Its Imaging in Living Cells

A new fluorescence probe 2,2'-(6-(4-(diethylamino) phenyl)-1,3,5-triazine-2,4-diyl)bis(1 H-pyrazole-1,3-diyl) diacetate(EATPA) based on 1, 3, 5-triazine was designed and synthesized. It exhibited distinct fluorescence quenching in the presence of silver ions that can be used for highly sensitive and selective detection of Ag+. Fluorescence titration and Job's plot analysis revealed the formation of [Ag(EATPA)_2]+ entity with high binding constant(1.43×10~4 L/mol) and low detection limit(0.882 μmol/L). Furthermore, live-cell imaging experiments demonstrated that EATPA is potentially applicable for the tracking of Ag+ in living cells.     

Synthesis of Calix[4] arene Thia Derivative and Extraction Effect of Substituents on Mercury( Ⅱ) and Lead( Ⅱ)

Calix[4]arene derivatives have been reported to possess high selectivity for metal ions.In order to analyze the extraction effect of substituents on Hg~(2+)and Pb~(2+),calix[4]arene derivatives containing hydroxyl,bromoethoxy and 1,11-dioxa-4,8-dithiahendecene were successfully synthesized,with their extraction effectiveness towards Hg~(2+)and Pb~(2+)were evaluated respectively.The results indicated that the phenolic hydroxyl in calix[4]arene improved the extraction ability on Hg~(2+)by promoting the formation of the negative oxygen ions that could bind with Hg~(2+)by coordination and ionic bonds.The extraction ability of 5,17-dinitro-26,28-(1’,11’-dioxa-4’,8’-dithiahendecene)-calix[4]arene(calix[4]arene thia derivative)was improved slightly due to the better coordination capacity for metal ions after introduction of 1,11-dioxa-4,8-dithiahendecene,which was a chelate-binding centre.Regarding to Pb~(2+),only 1,11-dioxa-4,8-dithiahendecene on molecule contributed to extraction due to the coordination bond.Since the metal ion with higher charge-to-radius ratio could coordinate with one ligand more stably,Pb~(2+)with higher charge-to-radius ratio than Hg~(2+)was coordinated and extracted by the calix[4]arene thia derivative more easily.Furthermore,extraction rates of the calix[4]arene thia derivative on both ions(Hg~(2+)and Pb~(2+))increased with the increase of pH value in acidic aqueous system(pH7).     

Prediction and Control of both Wrinkle Limit and Fracture Limit on Cylindrical Cup Deep-drawing (Ⅱ)

The prediction and control criterion of both the wrinkle limit and fracture limit on the cylindrical cup deep-drawing are given, and the prediction and control diagram of both the wrinkle limit and fracture limit are also given. The results show that it is suitable for no-flange cylindrical cup deep-drawing, narrow-flange cylindrical cup deep-drawing, wide-flange cylindrical cup deep-drawing/expanding compound forming and rigid punch expanding forming.     

Syntheses,Crystal Structures,and Fluorescence Properties of Two 2D→2D Coordination Polymers Based on the Flexible 4-Substituted Bis(1,2,4-triazole) Ligand

Two new 2 D → 2 D zinc(II) coordination polymers, [Zn(btre)0.5(nbdc)(H2 O)]n(1) and {[Zn(btre)0.5(Me Oip)(H2 O)2]·H2 O}n(2)(btre = 1,2-bis(1,2,4-triazol-4-yl)ethane, nbdc=3-nitro-1, 2-benzenedicarboxylate, Me Oip=4-methoxybenzene-1, 3-dicarboxylate) were synthesized at room temperature condition and characterized by IR spectra, elemental analyses, single-crystal and powder X-ray diffractions. Three sets of equivalent 2 D(6, 3) networks parallel polycatenated with each other to give a 2 D → 2 D network in 1 and 2. There are strong π-π interactions and hydrogen bonding interactions between adjacent parallel polycatenated 2 D(6, 3) network in 1. Only hydrogen bonding interactions exist in 2. Thermal stabilities and luminescence of 1 and 2 were investigated.     

Spectroscopic study on the photophysical properties of chlorine substituted tetraphenylporphyrin-histidine and its zinc(Ⅱ)complexes

The photophysical properties of ortho-CI,meta-CI and para-CI substituted tetraphenylporphy-rin-histidine and their zinc (II) complexes have been studied by means of steady-state absorption and fluo-rescence spectroscopies, as well as time-resolved fluo-rescence spectroscopy. For the cases of both free-base and zinc complexes, it was found that the ortho-chlorine substitution onto the phenyl rings significantly altered the fluorescence quantum yield, thefluorescence lifetime and the ratio between radiative and nonradiative deactivation rates of the porphyrin chromophore, i.e. the photophysical parameters were quite different from those of meta- and para-substituted compounds. On the other hand, however, the introduction of covalently-linked histidine did not exert much effects on the photophysical behavior of the porphyrin chromophore. The results are interpreted interms of the steric effect and the heavy-atom effect from the chlorine atoms substituted onto the phenyl rings.     

Spectroscopic study on the photophysical properties of chlorine substituted tetraphenylporphyrin-histidine and its zinc(Ⅱ)complexes

As the structural analogues of (bacterio)chlorophylls in photosynthetic organisms, porphyrins play an important role in building up artificial photosynthetic systems[13]. In natural photosynthetic pigment-protein complexes,certain amino acid residuals modulate the reactions ofcharge transfer and energy transfer via coordination andother types of interactions with chlorophyll molecules.For instance, in higher-plant photosynthetic reaction cen-ter PSⅡ, the oxidization-reduction system consistin…     

Surface Properties of the Microgels Based on N-isopropylacrylamide and Tert-butyl Acrylate by Using N,N′-methylene-bis(acrylamide) and Clay as Cross-linker

IntroductionMicrogel particles are spherical , covalently cross-linked polymer particles in the colloidal-size range from10to1 000nmthat swell or de-swell in response to externalsti muli[1 3], such as temperature , pH, os motic pressure ,ionic strength[4,5], which have potential applications innumerous fields , including drug delivery , chemicalseparation and s mart hydrogel fiber[6,7]. Ther mo-sensitiveaqueous dispersions of poly (N-isopropylacrylamide )(PNIPAM) microgel particles in the p…     

利用聚罗丹明B修饰碳纤维微电极测定维生素B6

利用循环伏安法(CV)研究了罗丹明B在碳纤维微电极上电聚合成膜的方法和条件,并对该聚合物膜修饰电极的电化学性质进行了探讨.详细研究了维生素B6(VB6)在该修饰电极上被电催化氧化的最佳条件,实验结果显示,在0.1mol/LNH3-NH4Cl(pH=8.89)+0.1mol/LNaCl体系中,VB6的浓度在6.80×10-6mol/L～7.29×10-4mol/L范围内与峰电流呈良好的线性关系,线性相关系数为0.9994;检测限可达9.73×10-7mol/L.样品8次平行测定结果的相对标准偏差不大于3.7%,样品回收率在92.6﹪～106.2﹪之间,可用于实际样品中VB6的定量分析.     

荧光法研究罗丹明B与Fenton试剂的作用

罗丹明B在水溶液中有强烈的荧光效应,激发和发射波长分别为358nm和575nm.加入Fenton试剂后,体系荧光强度明显下降,且在一定范围内与H2O2的浓度呈量效关系.测定体系反应前后荧光变化,可间接测定羟自由基产生的量.通过测定条件的研究,得出最佳实验条件:pH5.0,CRB1.92×10-6mol/L,CH2O24.8mmol/L,CFe2+6.4×10-4mol/L,反应时间15min以上.清除率实验证明了该方法的准确可靠.     

氢化物发生-原子荧光光谱法同时测定环境水中的砷和汞的研究

本文研究了用氢化物发生。原子荧光光谱法同时测定环境水中砷和汞.本法是在盐酸介质中,以硼氢化钾作还原剂,将待测元素转化为挥发性氢化物,以高纯氩气作为载气将挥发性氢化物从溶液中分离,并导入石英炉原子化器中原子化．以高效空心阴极灯作激发光源,被测元素原子受激发后发出原子荧光,荧光强度在一定范围内与被测元素的浓度成正比．讨论并确定了试验的最佳测定条件,方法的检出限：As为0．018μg／L,Hg为0．006μg／L,对As、Hg混合标准溶液（As：5ppb,Hg：0．5ppb）连续测定11次,相对标准偏差：As为2．4％,Hg为10％．并对不同来源的水样进行了分析,回收率为95％～110％．结果表明,该方法操作简便、灵敏度高、干扰少．     

高锰酸钾-罗丹明B化学发光体系测定硫酸双肼酞嗪

目的结合流动注射技术，建立一种化学发光测定硫酸双肼酞嗪的新方法。方法在硫酸介质中，高锰酸钾可氧化硫酸双肼酞嗪而产生微弱的化学发光，罗丹明B大大增强了反应体系的发光信号。利用发光强度与硫酸双肼酞嗪浓度在一定范围内呈线性关系进行硫酸双肼酞嗪的定量测定。结果测定硫酸双肼酞嗪的线性范围为5．0～800ng／mL，检出限为1．9ng／mL(3σ)。结论该方法已成功应用于复方降压片中硫酸双肼酞嗪含量的测定。     

不对称烷基亚砜对Hg(II)萃取行为的研究

文章在高氯酸介质中研究了正-戊基己基亚砜(n-PHSO)对Hg(II)的萃取行为,用斜率法确定萃合物的组成是Hg(ClO4)2·(n-PHSO)2,求得了平衡常数。考察了酸度和稀释剂对n-PHSO萃取Hg(II)的影响,并比较了正-戊基己基亚砜(n-PHSO)、正-丁基辛基亚砜(n-BOSO)、正-己基环己烷亚砜(n-HCHSO)、正-丁基戊基亚砜(n-BPSO)、二苯亚砜(BPSO)等几种不对称亚砜对Hg(II)萃取能力的大小。     

测定生物体内Cu~(2+)的荧光探针构建及应用研究

铜离子是人体必需的微量元素,广泛分布于生物组织中,其在基因表达、维持蛋白质结构和功能等方面发挥着重要作用,而荧光检测技术是现代分析科学中的一类重要方法。因此,设计并合成高灵敏度、高选择性、原位检测铜离子的荧光探针在生命科学中具有重要意义。文中在罗丹明骨架上引入噻吩杂环,合成了新型的特异性测定Cu~(2+)的荧光探针BOTC,在v(CH_3CN)∶v(HEPES)=1∶1(pH)=7. 40)缓冲溶液中实现了对铜离子的高灵敏高选择性荧光检测,探针在1～10μmol/L范围内呈良好的线性关系,最低检测限为0. 32μmol/L,并且在SH-SY5Y细胞内取得了良好的荧光成像效果。     

超高效液相色谱测定肉制品中的罗丹明B、孔雀石绿和结晶紫及其代谢物残留

提出了一种以超高效液相色谱同时检测肉制品中5种违禁合成色素的新方法.以甲醇-水(V(甲醇)∶V(水)=95∶5)作为提取剂,样品在80℃经微波辅助萃取5min,继以C18固相萃取柱净化,使用ACQUITY BEH C18分析柱,以乙腈-20mmol/L乙酸铵缓冲溶液(V(乙腈)∶V(乙酸铵)=80∶20,pH=5)作流动相,实现了5种色素的有效分离.在0.1～5.0μg/mL内,校准曲线呈良好的线性,相关系数r为0.994 5～0.999 5.该方法测定肉制品中罗丹明B、孔雀石绿、结晶紫、隐性孔雀石绿和隐性结晶紫的定量限分别为4.23,1.83,1.61,1.96,1.95μg/kg.对加标50μg/kg的牛肉香肠日内测定6次,5种分析物的精密度(以RSD表示)优于9.2%.在25μg/kg和75μg/kg添加水平,平均回收率为78.01%～109.2%,相对标准偏差小于10%.实验结果表明:该方法具有快速、灵敏和准确等优点,可用于肉制品中5种违禁色素的常规分析.     

Label-free selective sensing of Pb2+ lead(II) sensors based on the aggregation of a pyrene fluorescent probe

In the present work, we report a label-free fluorescence turn-on approach for the sensitive and selective sensing of Pb²⁺. Pyrene with one positive charge was used as the fluorescent probe, and thrombin aptamer (TBA), which was a G-rich oligonucleotide, was employed to form G-quadruplex with lead(II). When TBA and Pb²⁺ were mixed with lead(II) in an aqueous solution, it was folded into a stable G-quadruplex. Subsequently, a single-stranded nucleic acid-specific nuclease S1 was added. The G-quadruplex stabilized by Pb²⁺ lead(II) had markedly a significant resistant ability to nuclease S1 digestion. However, in the absence of Pb²⁺ lead(II), no quadruplex or less stable quadruplex was formed and TBA was digested by nuclease S1 in 3 min under the optimized experimental conditions. Finally, pyrene probe was mixed with oligonucleotide in Pb²⁺ lead(II). Electrostatic interactions between oligonucleotide (a polyanion) and the probe induced the aggregation of the probe, which in turn produced strong emission of the strong pyrene excimer emission. The intensity of the induced excimer emission was directly proportional to the amount of Pb²⁺ added. Our approach shows good selectivity and sensitivity for the detection of Pb²⁺ with a limit of detection limit as low as 800 nmol/L.     

基于双氧水检测的硼酸酯荧光探针的研究

以邻羟基苯乙酮和苯甲醛为原料经过羟醛缩合反应、氧化反应以及取代反应,合成了一种新型荧光探针,其结构经过1H NMR、MS进行了表征。利用荧光光谱,探讨了该探针对双氧水响应的光谱性能、选择性、p H值以及反应时间等因素。结果表明,该探针能很好地对双氧水进行检测。