Stir-bar sorptive extraction based on hydroxyl-functionalized zirconium-metal-organic framework for the detection of three quinolones in actual samples

A novel analytical method based on stir-bar sorptive extraction was proposed for the determination of three trace quinolones in fish and shrimp samples. UiO-66-(OH)₂, a hydroxyl-functionalized zirconium metal-organic framework, has been coated on frosted glass rods by an in situ growth method. The product, UiO-66-(OH)₂ modified frosted glass rods, has been characterized and key parameters have been optimized in combination with ultra-high-performance liquid chromatography. The detection limits of enoxacin, norfloxacin, and ciprofloxacin were 0.48–0.8 ng ml⁻¹, and the detection concentrations were in the range of 10–300 ng ml⁻¹, showing a good linear relationship. This method was used for the determination of three quinolones in aquatic organisms, and the recoveries in spiked fish and shrimp muscle tissue samples were 74.8%–105.4% and 82.5%–115.8%, respectively. The relative standard deviations were less than 6.9%. The established method combined stir-bar sorptive extraction based on UiO-66-(OH)₂ modified frosted glass rods with ultra-high-performance liquid chromatography, has good application prospects for the detection of quinolone residues in fish and shrimp muscle samples.     

一种镉基金属有机骨架材料对丙酮和Fe3+的荧光检测

以 1,3,5-三(4-羧基苯基)苯(H₃BTB)为配体,通过溶剂热法得到一种三维四重穿插结构的镉基金属有机骨架材料：(Me₂NH₂)[Cd(BTB)(DMF)]·DMF·H₂O(Cd-MOF)。通过单晶X射线衍射、粉末X射线衍射、红外分析、元素分析和热重分析表征了其组成和结构。荧光研究结果表明：Cd-MOF在含有丙酮或 Fe³⁺离子的溶液中均表现出荧光猝灭现象,其检测限(体积分数和浓度)分别为0.6%和0.89 μmol·L^-1,线性检测范围分别为2.0%~2.8%和0~0.05 mmol·L^-1。时间响应实验和可循环利用实验显示Cd-MOF可长时间、稳定且高效地检测丙酮和Fe³⁺离子。     

Facile synthesis of enzyme functional metal-organic framework for colorimetric detecting H2O2 and ascorbic acid

In this work,a metal-organic frameworks material MIL-88 was prepared easily using solvent-thermal method,and was first found to have catalytic activities similar to those of biological enzymes such as catalase and peroxidase.The material was characterized by XRD,SEM,TEM,EDX,FT-IR techniques and an N_2 adsorption method.It exhibited peroxidase-like activity through catalytic oxidation of the peroxidase substrate 3,3',5,5'-tetramethylbenzidine(TMB) in the presence of H_2O_2,producing a blue-colored solution.Under optimal conditions,the absorbance at 652 nm is linearly correlated with the concentration of H_2O_2 from 2.0×10~(-6) mol/L to 2.03×10~(-5) mol/L(R~2=0.981) with a detection limit of 5.62×10~(-7) mol/L(S/N=3).More importantly,a sensitive and selective method for ascorbic acid detection was developed using this material as a catalyst.The analytical method for ascorbic acid detection was observed to have a linear range from 2.57×10~(-6) mol/L to 1.01×10~(-5) mol/L(R~2=0.989) with a detection limit of 1.03×10~(-6) mol/L(S/N=3).This work suggests MOFs have advantages of preparing biomimetic catalysts and extends applications of the functional MOFs in the field of biosensor.     

Two alkynyl functionalized Co(II)-MOFs as fluorescent sensors exhibiting selectivity and sensitivity for Fe3+ and nitroaromatic compounds

Two alkynyl functionalized 3D frameworks with different structures were successfully synthesized for selective and sensitive detection of Fe³⁺ ions and nitroaromatic compounds through fluorescence quenching.     

一种镉基金属有机骨架材料对丙酮和Fe3+的荧光检测

以1,3,5-三（4-羧基苯基）苯（H₃BTB）为配体,通过溶剂热法得到一种三维四重穿插结构的镉基金属有机骨架材料：（Me₂NH₂）[Cd（BTB）（DMF）]·DMF·H₂O（Cd-MOF）。通过单晶X射线衍射、粉末X射线衍射、红外分析、元素分析和热重分析表征了其组成和结构。荧光研究结果表明：Cd-MOF在含有丙酮或Fe³⁺离子的溶液中均表现出荧光猝灭现象,其检测限（体积分数和浓度）分别为0.6%和0.89 μmol·L^-1,线性检测范围分别为2.0%~2.8%和0~0.05 mmol·L^-1。时间响应实验和可循环利用实验显示Cd-MOF可长时间、稳定且高效地检测丙酮和Fe³⁺离子。     

A high-efficiency and low-cost AEE polyurethane chemo-sensor for Fe3+ and explosives detection

An aggregation enhanced emission (AEE) polyurethane named STMPU-211 containing 0.13% mole concentration of 4,4′-((1Z,3Z)-1,4-diphenylbuta-1,3-diene-1,4-diyl) dibenzaldehyde (TABDAA) in the soft segments was synthesized and proved to be sensitive to Fe³⁺ and nitroaromatic explosives. The fluorescence of the AEE polyurethane was reduced in the presence of Fe³⁺, and almost quenched when 5000?μM Fe³⁺ was added. Meanwhile, the fluorescence intensity of STMPU-211 solution in DMF/water mixture was decreased when explosives like 2,4,6-trinitrophenol (PA) and 3-nitro-1,2,4-triazol-5-one (NTO) were applied. Especially, the quenching coefficient K_SV value of PA was 5.7?×?10⁶?M^?1, confirming that the polyurethane STMPU-211 could be a highly sensitive sensor for the detection of PA. Therefore, AEE polyurethanes with low concentration of TABDAA have promising applications in biological probe, environment monitoring and antiterrorism fields.     

功能性三价铕离子的金属有机骨架选择性荧光识别芘

成功设计并通过水热法合成了一种具有功能性三维结构的镧系金属有机骨架 Eu-4L,其配体为二苯胺四羧酸衍生物(H₄L)。Eu-4L 的骨架中含有 3D 空腔,且其比表面积较高。Eu-4L 不仅热稳定性较高,且在 pH 为 3~11 的范围内稳定性良好。Eu-4L可以作为荧光探针选择性识别稠环芳烃芘,其检测限为5 μmol·L^-1,具有较高的灵敏度,且具备可循环重复利用的特性。Eu-4L荧光识别芘的作用机理为稳态荧光识别机理。此外,对Eu-4L的荧光识别选择性、竞争能力也进行了详细地讨论。     

11-Mercaptoundecanoic acid functionalized gold nanoclusters as fluorescent probes for the sensitive detection of Cu2+ and Fe3+ ions

Metal ions are physiologically essential,but excessive metal ions may cause severe risk to plants and animals.Here,we prepared gold nanoclusters(Au NCs) protected by 11-mercaptoundecanoic acid(11-MUA),which have excellent fluorescence properties for the detection of metal ions.The results showed that the copper ions(Cu~(2+)) and iron ions(Fe~(3+)) in the solution have obvious quenching effect on the fluorescence intensity of Au NCs.The detection range of Fe~(3+) was 0.8–4.5 mmol/L(R~2= 0.992) and 4.5–11.0 mmol/L(R~2= 0.997).And Cu~(2+) has a lower linear range(0.1–1.0 mmol/L,R2= 0.993).When EDTA was added into the reaction system,it was observed that the quenching effect of Cu~(2+) and Fe~(3+)on Au NCs showed different phenomenon.Then,the effect of metal ions on the fluorescence of Au NCs was investigated.The selective detection of Cu~(2+) was achieved by EDTA masking of Fe~(3+).In addition,we realized the metal ions detection application of Au NCs in the serum     

均三嗪衍生物应用于Fe3+和Cu2+的选择性识别研究

合成了2,4-二甲基-6-(4’-N,N-二甲氨基苯乙烯基)-1,3,5-均三嗪(1)和2-苯乙烯基-4,6-二甲基-1,3,5-均三嗪(2)两种化合物,并对其进行了1H NMR,MS,元素分析等表征.采用吸收光谱法研究了金属离子与化合物间的相互作用,结果显示:化合物1对Fe3+和Cu2+表现出高选择性光谱响应,其最大吸收波长由393 nm分别红移至525 nm和513 nm,溶液颜色由黄色变为粉红色.化合物1与Fe3+结合形成1∶1型配合物,其结合常数为1.8×104L mol-1;与Cu2+结合形成2∶1型配合物,其结合常数为2.6×1010L mol-1.化合物2仅对Fe3+呈现显著的光谱变化,其最大吸收波长由304nm红移至357 nm,而Cu2+的加入未引起光谱明显变化,2与Fe3+亦形成1∶1型配合物,结合常数为1.0×105L mol-1.结果表明Fe3+可能与化合物1和2中三嗪N配位,而Cu2+与化合物1中甲氨基中的N配位.同时考察了其它金属离子如Li+,K+,Mg2+,Ca2+,Co3+,Ni2+,Ag+,Cd2+,Hg2+和Zn2+等离子对化合物1和2吸收光谱的影响,结果显示两者光谱均无明显变化,据此提出了高选择性Fe3+,Cu2+的识别体系.     

Cu2＋和Fe3＋与明胶的相互作用

利用荧光猝灭法, 研究了不同温度、酸度下, Cu2＋和Fe3＋与明胶的相互作用.计算了猝灭常数和结合常数.紫外光谱和显微红外光谱的测定结果表明, Cu2＋、Fe3＋与明胶分子中的酰胺键发生了作用.探讨了猝灭机理.计算出的热力学函数表明,在Cu2＋、Fe3＋与明胶的相互作用过程中熵变起主要的作用.     

基于硼-二吡咯亚甲基二聚体的红光三价铁离子探针的合成与性质

在硼-二吡咯亚甲基(BOIDPY)的β-β(2/6)位偶联得到一种新型的红光二聚体BODIPY荧光探针1,该探针可以发生高效的能量转移,假斯托克斯位移可以达到222nm.探针1能够专一性地识别三价铁离子,不受其它常见金属离子的干扰,可以作为检测三价铁离子的高选择性的探针.     

Fe3+和Fe2+对原代培养的成骨细胞增殖、分化和矿化功能的影响

采用噻唑蓝(MTT)法、碱性磷酸酶(ALP)比活性测定、油红O染色和茜素红染色及定量分析,研究了不同浓度的Fe3+和Fe2+对原代培养的成骨细胞增殖、分化及矿化功能的影响.结果表明:浓度为1×10-9～1×10-4 mol·L-1的Fe3+和Fe2+促进成骨细胞增殖,但是在较高浓度1×10-3 mol·L-1时,它们则抑制成骨细胞增殖.与成骨细胞作用48 h,浓度为1×10-8～1×10-4 mol·L-1的Fe3+和Fe2+抑制其分化,但在较低的浓度1×10-9 mol·L-1时则对其分化没有影响:进一步延长作用时间为72 h,Fe3+对成骨细胞分化没有影响,除1×10-6mol·L-1浓度的Fe2+促进成骨细胞分化外,其他浓度的Fe2+则抑制其分化;测试浓度下的Fe3+对成骨细胞向脂肪细胞的横向分化表现为抑制或没有影响,而Fe2+的影响则依赖于浓度和作用时间.在1×10-8～1×10-5mol·L-1浓度范围内,Fe3+和Fe2+对矿化结节的影响表现出相反的效应.在较高浓度(1×10-4mol·L-1)下,它们促进矿化节结的形成,而在较低浓度(1×10-9mol·L-1)下,Fe3+抑制矿化节结的形成,Fe2+则没有影响.结果提示:浓度.作用时间和铁离子的价态都是影响Fe3+和Fe2+生物效应(从毒性到活性,从损伤到保护,从上调到下调)转变的关键因素.     

Synthesis and thermodynamic properties of a metal-organic framework: [LaCu6(μ-OH)3(Gly)6im6](ClO4)6

A metal-organic complex, which has the potential property of absorbing gases, [LaCu₆(μ-OH)₃(Gly)₆im₆](ClO₄)₆ was synthesized through the self-assembly of La³⁺, Cu²⁺, glycine (Gly) and imidazole (Im) in aqueous solution and characterized by IR, element analysis and powder XRD. The molar heat capacity, C_p,m, was measured from T = 80 to 390 K with an automated adiabatic calorimeter. The thermodynamic functions [H_T − H_298.15] and [S_T − S_298.15] were derived from the heat capacity data with temperature interval of 5 K. The thermal stability of the complex was investigated by differential scanning calorimetry (DSC).     

四种同构镧系金属有机框架的合成、结构和荧光传感Fe3+和盐酸环丙沙星

采用溶剂热法,以含氮四羧酸3,5-二(3′,5′-二羧苯)-1H-1,2,4-三唑(H₄BDT)为配体,成功合成了4种同构镧系金属有机框架(Ln-MOFs)：{[La₃(BDT)₂(HCOO)(H₂O)₅]·0.5H₂O·3DMF}_n (1)、{[Ce₃(BDT)₂(HCOO)(H₂O)₅]·3DMF}_n (2)、{[Pr₃(BDT)₂(HCOO)(H₂O)₅]·3DMF}_n (3)和{[Nd₃(BDT)₂(HCOO)(H₂O)₅]·3DMF}_n (4),并采用单晶X射线衍射、粉末X射线衍射、元素分析、热重、红外、N₂吸附实验和荧光光谱对其进行表征。结果表明,这些Ln-MOFs均为单斜C2/m空间群晶体,是双核为无机建筑单元的三维介孔结构。其中2可选择性荧光检测Fe³⁺离子和盐酸环丙沙星药物分子,检测限分别为4.59和0.77 μmol·L^-1。     

功能性三价铕离子的金属有机骨架选择性荧光识别芘

成功设计并通过水热法合成了一种具有功能性三维结构的镧系金属有机骨架Eu-4L,其配体为二苯胺四羧酸衍生物(H4L)。Eu-4L的骨架中含有3D空腔,且其比表面积较高。Eu-4L不仅热稳定性较高,且在pH为3～11的范围内稳定性良好。Eu-4L可以作为荧光探针选择性识别稠环芳烃芘,其检测限为5μmol·L^-1,具有较高的灵敏度,且具备可循环重复利用的特性。Eu-4L荧光识别芘的作用机理为稳态荧光识别机理。此外,对Eu-4L的荧光识别选择性、竞争能力也进行了详细地讨论。     

用于痕量监测Zr4+、Cr2O72-、Fe3+、HPO42-和指纹识别的功能化Eu3+/Tb3+配位聚合物荧光探针的构筑

采用芳香族π共轭及含氮原子有机连接剂,合成同构铽、铕发光配位聚合物(CPs){[Eu(PLIA)_1.5(H₂O)₂]·H₂O}_n (1)和{[Tb(PLIA)_1.5(H₂O)₂]·H₂O}_n (2),其中H₂PLIA=5-((吡啶-4-基甲基)氧基)苯-1,3-二甲酸。对合成的配合物进行了结构测定、表征和荧光痕量识别实验研究。2个同构配合物具有理想的三维框架结构,π…π堆积及氢键等弱相互作用增强了其化学稳定性;表征显示配位聚合物1和2具有良好的荧光性质、结晶性、热力学稳定性及结构完整性,可作为荧光传感的材料。1和2对水溶液中的Zr⁴⁺、Cr₂O₇^2-和Fe³⁺、HPO₄^2-具有选择性好、灵敏度高的荧光识别能力,其检出限分别为0.139 μmol·L^-1(1,Zr⁴⁺)、0.626 μmol·L^-1(1,Cr₂O₇^2-)、0.430 μmol·L^-1(2,Fe³⁺)、1.36 μmol·L^-1(2,HPO₄^2-)。探究了1和2作为探针的荧光猝灭机理。更有趣的是,1和2具有指纹识别性能,其荧光指纹纹路清晰连贯,细节明显,可被清晰观察。     

两种3D微孔Zn-MOF对水溶液中Fe3+、Cr2O72-和丙酮分子的荧光传感(英文)

通过溶剂热法合成了2种三维微孔锌金属有机框架材料,其分子式为[Zn₃(DBA)(OH)(1,10-phen)₂]_n (1)和{[Zn₂(HDBA)(4,4′-bipy)_1.5]·H₂O}_n (2)(H₅DBA=3,5-二(2′,4′-对羧基苯基)苯甲酸;1,10-phen=1,10-菲咯啉;4,4′-bipy=4,4′-联吡啶)。结构分析表明,配合物1为三核锌基金属单元的三维微孔骨架,配合物2为双核锌基的微孔结构。与2相比,配合物1在水中具有较强的发光性能,可作为检测Fe³⁺、Cr₂O₇^2-和丙酮分子的发光传感器,具有较高的选择性和灵敏度。     

Electrochemical sensor for Cd2+ and Pb2+ detection based on nano-porous pseudo carbon paste electrode

An electrochemical sensor based on self-made nano-porous pseudo carbon paste electrode (nano-PPCPE) has been successfully developed, and used to detect Cd²⁺ and Pb²⁺. The results showed that the electrodes can quantitatively detect trace Cd²⁺ and Pb²⁺, and with satisfied limit of detection, which has great significance in electrochemical analysis and detection.     

Yb3+/Tm3+掺杂的NaY(WO4)2纳米晶的制备及发光特性

以聚乙二醇为配位剂,用水热法制备出纳米级上转换发光粉Yb3+和Tm3+共掺杂的NaY(WO4)2。研究了不同cYb/cTm对上转换发光强度的影响,实验表明当cYb/cTm=5∶1时,上转换发光强度最强。用XRD,SEM确定了Yb3+和Tm3+共掺杂的NaY(WO4)2是四方晶系,其粒径在25~35 nm范围,且分散均匀。用980 nm半导体激光器(LD)对其进行激发,在室温下观察到了365 nm附近紫外发射峰、456 nm,476 nm附近的蓝光发射峰和648 nm附近的红光发射峰,分别对应于Tm3+离子的1D2→3H6,1D2→3F4,1G4→3H6和1G4→3F4的跃迁。根据泵浦功率与发光强度的关系得出紫外发射峰、蓝光和红光发射均为双光子过程。     

[M(phen)3][Ni(mnt)2](M2+=Ni2+，Fe2+；phen=1，10-菲咯啉，mnt2-=马来二腈二硫烯)离子对配合物的合成、晶体结构、电子光谱和磁性质

本文制备了2种新的离子对配合物[M(phen)3][Ni(mnt)2](phen=1,10-菲咯啉,mnt2-=马来二腈二硫烯;M2+=Ni2+,1;Fe2+,2),并进行了结构表征。2种离子对配合物晶体的空间群都为P21/n,具有类似的晶胞参数和堆积结构。紫外可见-近红外光谱显示在近红外区域没有出现明显的吸收峰。在2到400 K的温度范围内,化合物1表现居里-外斯型的顺磁性行为,并在磁性[Ni(phen)3]2+离子之间存在弱的反铁磁作用,而且在八面体配位环境下Ni2+离子自旋基态S=1。化合物2在40 K向上显示抗磁性,意味[Fe(phen)3]2+离子处于低自旋态。低于40 K时,弱居里尾巴可能是由于小部分顺磁性[Ni(mnt)2]-杂质导致的。