A Highly Selective Fluorescent Chemosensor for Cu2+

A new Zn²⁺ probe L2-Zn(L2=naphthofuran carbonylhydrazone derivant) was synthesized as a fluorescence chemosensor for Cu²⁺, by which Cu²⁺ ion could be detected with high selectivity and sensitivity in a wide pH range via a displacement “turn-off” signaling strategy. Whereas the coordination between Zn²⁺ and L2 resulted in a considerable enhancement of typical luminescence of a naphthalofuran group in complex L2-Zn, the addition of Cu²⁺ ion led to a dramatic decrease in the emission intensity of probe L2-Zn at about 503 nm(excitation at 423 nm). The competitive fluorescent experiments showed that other metal ions, such as Hg²⁺, Fe³⁺, Ag⁺, Ca²⁺, Co²⁺, Ni²⁺, Cd²⁺, Pb²⁺, Zn²⁺, Cr³⁺ and Mg²⁺ could not impact the detection of Cu²⁺. The detection limit of the novel probe L2-Zn for Cu²⁺ ion was as low as 2.3×10^-7 mol/L, which is far lower than the guideline value of 1.6×10^-5 mol/L of the United States Environmental Protection Agency.     

Synthesis of Highly Sensitive Fluorescent Probe Based on Tetrasubstituted Imidazole and Its Application for Selective Detection of Ag+ Ion in Aqueous Media

A small molecule fluorescent probe, 4-[2-(4-chlorophenyl)-4,5-diphenyl-1H-imidazol-1-yl]aniline(L) for detecting Ag⁺ ion was gently synthesized via one-pot multi-component reaction catalyzed by H₃[PW₁₂O₄₀] under solvent-free microwave irradiation. When the concentration of Ag⁺ ion changed from 0 to 8.0×10⁻⁶ mol/L in the solution of H₂O/CH₃OH(19:1, volume ratio), the fluorescence emission spectrum was blue-shifted and accompanied by a gradual increase in fluorescence intensity with a low detection limit of 3.0×10⁻¹¹ mol/L. Moreover, UV-Vis absorption titration experiment demonstrated a 1:1 stoichiometric ratio and an association constant of (9.95±0.44)×10⁵ L/mol between probe L and Ag⁺ ion, and thus their complexation mechanism was also proposed and verified. More importantly, this fluorescent probe was remarkably specific for Ag⁺ ion under the interference of other metal ions and exhibited a wide pH application range of 4.0-8.0. Additionally, preliminary application of this probe was also carried out and satisfactory results were shown.     

A Novel Coumarin-based Fluorescence Chemosensor for Fe^3＋

A novel coumarin derivative[7-diethylamino-2-oxo-2H-chromene-3-carboxylic acid（6-amino-pyridin2-yl）-amide,CFe1] has been synthesized and its potential application as a chemosensor for the detection of metal ions has been further investigated.The responses of CFe1 to Fe^3＋ were studied by fluorescence emission spectrometry in the presence of other metal ions such as Al^3＋,Ba^2＋,Ca^2＋,Co^3＋,Cr^3＋,Cu^2＋,Fe^2＋,Hg^2＋,Mg^2＋,Mn^2＋,Na^＋,Ni^＋,Pb^2＋,Zn^2＋,K^＋,and Ag^＋.CFe1 showed a good selectivity for Fe^3＋ with fast response,a wide pH span of 3.3-9.18,and a large Stocks shift.CFe1 in the presence of Fe^3＋ and ethylene diamine tetraacetic acid（EDTA） makes the blue solution fade to colorless,which is due to the formation of CFe1-Fe^3＋ complex instead of any catalytic action of Fe^3＋.Furthermore,the imaging of Fe^3＋ in cultured single mice microglia cells was realized with the aid of CFe1,indicating that CFe1 has a great potential to be used as promising models for the future design of novel and robust chemosensor for metal ion detection in the field of biomedical and environmental analyses.     

识别过渡金属离子的1,8-萘二甲酰亚胺多胺衍生物荧光传感器的研究

A series of fluorescent chemosensors 1-3 were synthesized to detect transition metal ions. At the room temperature, fluorescence intensities of these chemosensors in acetonitrile without transition metal ions were found to be very weak, due to the process of the e±cient intramolecular photoinduced electron transfer (PET). However, after addition of the transition metal ions, the chemosensor 1-3 exhibits obvious fluorescence enhancement. Moreover, the intensity of the fluorescence emission of chemosensors increases significantly in the presence of Zn2+ and Cd2+. The fluorescent chemosensors with different polyamine as receptors show diverse a±nity abilities to the transition metal ions and signal the receptor-metal ion interaction by the intensity change of fluorescence emission.     

基于菲并咪唑的ON⁃OFF⁃ON双比色荧光探针及细胞成像

设计合成了对称型菲并咪唑荧光探针PIP-ph-PIP, 并对其结构进行了表征和确认. 随着探针溶液中水体积分数的增加, 探针的聚集程度逐渐增加, 荧光强度先增强后猝灭. 荧光光谱测试结果表明, 在水相体系中探针PIP-ph-PIP能以ON-OFF-ON的方式分别对Ag⁺和SCN^-, Cu²⁺和PO³₄ ^-进行连续识别, 且连续识别效果可通过裸眼比色观察, 其中对Ag⁺识别具有超低检出限(6.1 nmol/L). 结果表明, 探针PIP-ph-PIP可应用于活体HeLa细胞中Ag⁺和Cu²⁺的定性分析及实际水样中Ag⁺和Cu²⁺的定量检测.     

Ag+存在下催化还原铬黑T及应用于Ag+检测

以铬黑T(EBT)为探针,在有Ag⁺存在的最优条件下,EBT被NaBH 4催化还原,体系在445 nm发射波长处荧光强度明显增强,基于此构建一种光学测定溶液中微量Ag⁺的方法。在最优条件下,Ag⁺浓度在(7.5×10-9~1.0×10^-6 mol·L^-1)范围内呈良好的线性关系,线性回归方程为ΔI F=5.59×10⁸ c-31(c,mol·L^-1,r=0.9966),Ag⁺的最低有效检测浓度为6.0×10^-8 mol·L^-1。在最优条件下,运用该方法对样品中Ag⁺浓度进行检测,样品中Ag⁺浓度的检测回收率在98.8%~102.4%之间,RSD=2.1%。该检测方法能够对水溶液中微量的Ag⁺进行有效定量检测,且操作简单、检测限低、灵敏度高。     

Target-triggered inhibiting oxidase-mimicking activity of platinum nanoparticles for ultrasensitive colorimetric detection of silver ion

A facile colorimetric method for sensitive and selective detection of Ag⁺ is successfully developed based on the excellent oxidase-like activity of chitosan-stabilized platinum nanoparticles and the strong metallophilic Pt²⁺-Ag⁺ interactions.     

基于银离子与DNA相互作用的比率型电化学传感器用于银离子的检测

利用银离子(Ag⁺)可与DNA中胞嘧啶碱基(C)相互作用的性质, 构建了一种用于检测Ag⁺的比率型电化学传感器. 以铬金属有机骨架材料(Cr-MIL-101 NH₂)标记的单链DNA作为信号探针(Cr-MOFs-SP), 电解质溶液的二茂铁甲酸作为内部参考探针(Fc-RP), 在Ag⁺存在的情况下, 可以检测到Cr-MOFs的信号. 同时, 二茂铁甲酸的信号几乎保持稳定, 因此, Ag⁺浓度可以通过I_Cr-MOFs-SP/I_{Fc- RP}的比率响应进行监测. 所制备的比率型生物传感器可有效消除外界环境影响和避免电化学背景信号, 提高了检测的重现性、 准确性和灵敏度. 具有三维结构的DNA四面体纳米材料(NTH)可有效消除DNA的非特异性吸附. 同时, 所设计的DNA NTH增强了机械刚度, 可以增加Ag⁺的捕获量和信号物质的负载量, 进一步提高了检测灵敏度. 该比率型生物传感器对Ag⁺的检测具有良好的选择性、 较宽的线性范围(0.1~100 nmol/L)和较低的检出限(33 pmol/L). 将此传感器用于滇池水样中Ag⁺的含量测定, 回收率为96.8%~103.0%, 表明此传感器具有潜在的实际应用前景.     

DNA银纳米簇在功能核酸荧光生物传感器中的应用

DNA银纳米簇(DNA-AgNCs)是以DNA为模板, 通过碱基杂环上的N原子与Ag⁺结合, 用NaBH₄将Ag⁺还原得到的具有荧光性质的新兴纳米探针. 由于DNA-AgNCs具有合成方法简单、 生物相容性好和荧光发射波长可调等优点, 使其在分析检测等领域具有广泛的应用. 本文对DNA-AgNCs的合成和荧光性质两个方面进行了综述, 分类总结了以DNA-AgNCs为无标记荧光探针在功能核酸荧光生物传感器方面的应用, 对其不足与应用潜力进行展望, 以期为未来的研究与应用提供借鉴.     

Novel Fluorescent Chemosensors Based on Tryptophan Unit for Cu2+ and Fe3+ in Aqueous Solution

We reported four fluorescent chemosensors containing tryptophan units. The fluorescence spectrum titration experiments suggest that chemosensors 1, 2, 3 and 4 are highly selective for Cu²⁺ and Fe³⁺ over Li⁺, Na⁺, K⁺, Co²⁺, Zn²⁺, Ni²⁺, Hg²⁺ and Cr³⁺ via forming complexes with Cu²⁺ or Fe³⁺, which is confirmed by dramatical quench of fluoreseence in aqueous solution at pH 7.4, thus making all the chemosensors suitable for Cu²⁺ and Fe³⁺ fluorescent sensors.     

碘化钾-十六烷基三甲基溴化铵-水体系液固分离银的研究

本文利用碘化钾-十六烷基三甲基溴化铵-水微晶吸附体系研究了银离子的液固分离行为.分别考察了KI用量、CTMAB用量、溶液酸度、盐和放置时间对分离效率的影响,结果表明,当2％碘化钾溶液溶液和2.0×10-3 mol·L-1 CTMAB溶液的用量均为1.0 mL时,Ag+、I-、CTMAB+形成的三元缔合物AgI2-·CT...     

具有荧光增强性能的罗丹明B衍生物的合成及其对汞离子的检测

利用汞离子可以诱导罗丹明B衍生物的螺环结构发生开环反应并产生荧光增强效果这一特性,设计并合成了两种新型的荧光化学传感器2-噻吩甲醛罗丹明B酰肼(RhBTh)和苯甲醛罗丹明B酰肼(RhBAr),并研究了二者在汞离子检测中的应用.研究结果表明,RhBTh与RhBAr对汞离子均表现出非常好的荧光增强效果,检测过程中其它金属离子不会对检测结果产生明显的干扰.二者对汞离子的检测限分别为7.8 nmol/L和12.5 nmol/L.实验表明RhBTh和RhBAr对汞离子均具有良好的灵敏度和选择性.     

Transport and separation of Ag(+) and Zn(2+) by donnan dialysis through a monovalent cation selective membrane

Donnan Dialysis of Ag⁺ and Zn²⁺ was investigated through a cation exchange membrane (CMS Neosepta) when a proton concentration difference was maintained between the two sides of the membrane. Developed for the production of brine from sea water, CMS Neosepta showed a higher permeability to monovalent than to bivalent cations. Several physico-chemical parameters have been determined (electrical resistance, membrane potential, sorption of electrolytes, Zn²⁺ and Ag⁺ diffusion coefficients). The flux of Ag⁺ and the diffusion potential in the membrane increase with HNO₃ concentrations. Ag⁺ and Zn²⁺ can be separated because of the preferential membrane transfer for Ag⁺.     

N,N-二甲基吡啶苯甲醛缩对二甲氨基苯甲酰腙的合成及对Cu2+的选择性识别

设计合成了可用于识别铜离子的化合物N,N-二甲基吡啶苯甲醛缩对二甲氨基苯甲酰腙(1), 通过¹H NMR, ¹³C NMR和MS等对其结构进行了表征; 采用荧光光谱和吸收光谱法研究了化合物1与金属离子间的相互作用. 结果表明, 化合物1对Cu²⁺ 呈现良好的选择性, Cu²⁺ 的加入使化合物1的荧光强度增强12.5倍, 加入其它金属离子如Fe³⁺, Zn²⁺, Pb²⁺, Hg²⁺, Cd²⁺, Co²⁺, Ni²⁺, Li⁺, K⁺, Ca²⁺, Mg²⁺ 和 Ag⁺, 仅引起化合物1荧光强度的微降. 采用双倒数线性回归拟合法计算可知, 化合物1与Cu²⁺ 形成了1: 1型强发光配合物, 结合常数为2.0×10⁷ L/mol.     

Ag+/Ag/ZnO多孔纳米结构纤维材料的制备及可见光催化性能

借助棉花纤维模板, 采用两步法制备了Ag⁺/Ag/ZnO多孔纳米结构纤维材料, 并利用X射线衍射(XRD)、 X射线光电子能谱(XPS)、 扫描电子显微镜(SEM)和紫外-可见光谱(UV-Vis)等对其进行了表征. 以亚甲基蓝(MB)的脱色降解为模型反应, 考察了银修饰量(摩尔分数, 0~1.50%)对ZnO纳米结构纤维材料光催化性能的影响. 结果表明, 利用模板辅助的两步法制备了Ag⁺-Ag共修饰的ZnO多孔纳米结构纤维材料Ag⁺/Ag/ZnO, Ag⁺和Ag通过改变ZnO的晶胞结构、 光吸收特性及形貌等影响其光催化性能; 在可见光条件下, Ag⁺/Ag/ZnO的催化性能优于纯ZnO, 且与修饰量有关.     

荧光性自组装双层膜的制备及其性能研究

借助Au-S化学键的作用,在金基底上组装DL-半胱氨酸,利用DL-半胱氨酸与1-萘胺乙酸(NAA)的静电吸引作用在金表面间接组装荧光试剂NAA,从而构建了双层自组装膜NAA/Cys/Au.该自组装膜有较强的荧光信号,能被Cu²⁺猝灭,并具有较好的可逆再生性能,可用于超痕量铜离子的界面荧光测定,对Cu²⁺的检出下限为7.87×10^-11mol/L.同时采用电化学、荧光光谱及电子能谱等方法表征自组装膜的结构,并采用电化学阻抗谱技术和循环伏安法研究自组装膜在K₃[Fe(CN)₆]/K₄[Fe(CN)₆]溶液中的电化学行为研究.结果表明,金表面组装的单层膜具有良好的“针孔”效应,组装上荧光试剂之后形成的无“针孔”缺陷的自组装双层膜对溶液与基底间的界面电子转移有强烈的阻碍作用.     

A naphthalimide–calixarene as a two-faced and highly selective fluorescent chemosensor for Cu or F

A new naphthalimide–calix[4]arene was synthesized as a two-faced and highly selective fluorescent chemosensor for Cu²⁺ or F⁻. This chemosensor displayed a selective fluorescence quenching effect only with Cu²⁺ among the various metal ions. On the other hand, among the various anions, the title chemosensor displayed a selective fluorescence quenching effect only with F⁻. The binding mode with F⁻ was further investigated using fluorescence changes and ¹H NMR experiments.     

Rhodamine 6G-based Chemosensor for the Visual Detection of Cu2＋ and Fluorescent Detection of Hg2＋ in Water

A novel water soluble chemosensor 1 based on rhodamine 6G spirolactam scaffold has been synthesized and characterized.Upon addition of a wide range of the environmentally and biologically relevant metal ions,chemosensor 1 shows a colorimetric selective Cu2＋ recognition from colorless to pink confirmed by UV-Vis absorption spectral changes,while it also exhibits a fluorometric selective Hg2＋ recognition by fluorescence spectrometry.An absorption enhancement factor over 17-fold with 1-Cu2＋ complex and a fluorescent enhancement factor over 45-fold with 1-Hg2＋ complex were observed.Their recognition mechanisms were assumed to be a 1：1 stoichiometry for 1-Cu2＋ complex and a 1：2 stoichiometry for 1-Hg2＋ complex,respectively,which were proposed to be different ligation leading to the ring-opening of rhodarnine 6G spirolactam.Furthermore,the detection limits for CU2＋ or Hg2＋ were 3.3 × 10-8 or 1.7x 10-7 mol/L,respectively.     

Ag+掺杂聚苯胺的制备及其电容特性研究

以苯胺为单体,采用界面聚合法合成了不同浓度的Ag⁺掺杂的聚苯胺(PANI/Ag⁺),使用傅里叶变换红外光谱（FT-IR）、X射线衍射（XRD）和场发射扫描电镜（SEM）等手段对其结构和形貌进行了分析和表征. 在0.5 mol•L^-1 Na₂SO₄电解液中,通过循环伏安（CV）、恒流充放电（CP）以及电化学阻抗（EIS）等技术研究了其电化学性能. 结果表明,当电流密度为5 mA•cm^-2时,PANI/0.12mol•L^-1 Ag⁺的比电容达529 F•g^-1,循环1000次后比电容保持51%,相对于无Ag⁺掺杂的PANI,表现出更优良的电化学电容特性.     

多组分氧化物Ag－Bi－V－Mo－O催化作用的光电子能谱研究

对于烃类选择氧化反应中复合氧化物的催化作用,普遍认为是Redox机理.迄今对于含有钥、秘复合氧化物催化剂的活性中心和作用机理还存在不同的看法.