基于石墨烯修饰的铜离子印迹电化学传感器研制与应用

以铜离子为模板离子,多巴胺为功能单体,采用电聚合法在石墨烯修饰碳电极表面成功制备对铜离子有高选择性和高灵敏性的印迹电化学传感器。采用差分脉冲伏安法和循环伏安法对该印迹传感器的电化学行为进行详细研究。优化检测条件,该印迹电化学传感器的响应电流与铜离子浓度的负对数在5×10_-6~5×10_-11 mol/L的浓度范围内呈良好的线性关系,最低检测限为1.0 × 10_-11mol/L。该印迹电化学传感器成功用于实际水样中的微量铜离子分析。     

铜离子印迹传感器的制备及其性能研究

以铜离子为模板,邻苯二酚为功能单体,在玻碳电极表面进行电聚合,成功制备了铜离子印迹聚合物膜,并采用差分脉冲伏安法对铜离子电化学传感器的性能进行了分析研究。铜离子浓度在1.0×10^-7 ～1.0×10^-4 M时,与峰电流呈良好的线性关系,其线性回归方程为y=0.2347 x+3.1227,其相关系数为0.9939,检出限为1.0×10^-8 M。此印迹电极可用于环境水样中的微量铜离子的检测。     

多肽荧光传感器检测铜离子

基于铜离子对罗丹明B标记的多肽的荧光猝灭作用, 构建了一种用于铜离子检测的荧光传感器. 利用共振光散射分析、 紫外-可见吸收光谱、 荧光寿命测试和圆二色光谱研究了铜离子检测的传感机理, 发现铜离子的加入诱导多肽结构发生变化而使罗丹明B荧光团彼此靠近, 从而导致铜离子与多肽之间发生聚集诱导荧光猝灭. 实验结果表明, 该传感器检测铜离子的线性范围为5×10^?4~1×10^?2 μmol/L和0.1~7 μmol/L, 检出限为0.29 nmol/L, 且拥有良好的选择性, 能用于湖水样品中铜离子的检测.     

含萘基团对铜离子具有高选择性的化学荧光传感器

设计合成了一种新的含萘和二吡啶甲基胺基团的荧光化学传感器,并利用氢核磁波谱和质谱对其结构进行了表征.新合成的化合物在乙腈和水的混合溶液中表现出了对二价铜离子具有很高的选择性,与铜离子的键合增强了其荧光强度.荧光和激发光谱滴定表明传感器分子与二价铜离子形成了1∶2的配合物.化合物中的N与铜离子的配位阻止了电子从分子中的N...     

基于环糊精配体骨架化合物的铜离子电化学行为及其检测

采用绿色环保、生物兼容的寡糖(γ-环糊精)配体,与钾合成新型金属有机骨架化合物K+-CDMOFs,并对其进行透射电镜、傅立叶红外光谱和X射线衍射表征。用循环伏安法和差分脉冲伏安法研究了铜离子在K+-CD-MOFs修饰玻碳电极上的电化学行为,并对电解液、p H值和扫速进行优化。结果显示,在p H 5.0醋酸缓冲溶液,扫描范围-0.4~0.4 V,扫速0.1 V/s的条件下,铜离子浓度在0.1~91.7 mg/L范围内与其峰电流呈良好线性关系,检出限(S/N=3)为0.018 mg/L,表明这种新型材料有较好的电化学活性。同时考察了钙、锌、镁、铅、镉、汞离子对铜离子测定的影响,结果显示合成材料表现出良好的选择性,除汞离子外,其他阳离子对峰电流无明显影响。该方法灵敏度高、重现性好、稳定性高,具有一定的抗离子干扰能力,可快速、准确用于工业废水中铜离子的测定。这种新型有机骨架材料制备的电化学传感器在重金属检测中具有一定的应用潜力。     

镍-氧化镍/铜-氧化亚铜复合纳米粒子修饰玻碳电极测定过氧化氢

在含镍离子和铜离子的溶液中用循环伏安法在玻碳电极(GCE)表面电化学沉积一层镍-氧化镍及铜-氧化亚铜纳米粒子 ( Ni /NiO、 Cu/Cu₂O),在-0.3 V电位条件下,该传感器能催化还原H₂O₂。用安培法测定H₂O₂的响应电流与浓度在2.5×10^-6 ~2.8×10^-3 mol/L范围内呈线性关系,研究了各种实验条件对H₂O₂传感器性能的影响。该传感器制作简单, 使用寿命长,在实际试样的回收率测定中,结果满意。     

基于铜离子与DNA相互作用的铜离子检测

利用铜离子(Cu~(2+))可与DNA分子中的碱基相互作用形成络合物的性质,将Cu~(2+)富集在DNA修饰电极表面,进而采用微分脉冲伏安法(DPV)实现了铜离子的检测.此外,由于乙二胺四乙酸(EDTA)对Cu~(2+)具有更强的络合能力,富集于DNA修饰电极表面的Cu~(2+)很容易被洗脱液中的EDTA络合,从而实现修饰电极的再生和重复利用.实验结果表明,在最佳实验条件下,Cu~(2+)浓度在2.0×10-6~1.0×10-5mol/L和2.0×10-5~1.0×10-4mol/L范围内与其相对还原峰电流强度(I-I0)呈良好的线性关系,且该传感器简单、稳定,可循环使用.     

基于荧光猝灭的铜传感器研究

研究了过渡金属离子对荧光分子 1 萘胺二乙酸钠 (NADA)的荧光猝灭现象及其猝灭机理 ,并基于此建立铜离子传感体系。该铜离子传感器的检测限为8.2 7× 1 0 - 6mol/L ,定量检测范围为 2 .6 9× 1 0 - 5～ 1 .2 0× 1 0 - 4 mol/L。     

碘离子对铜阳极溶出的影响

本文用阳极溶出伏安法直接在玻璃电极上测定铜。在Ｈ２ＳＯ４介质中加入微量碘离子使灵敏度大大提高，可测定１ｎｇ／ｍＬ铜。该方法用于人体血清中铜的测定，结果令人满意，证明在碘离子存在下，铜溶出时生成了碘化亚铜沉淀，加速了溶出反应的进行，利用溶度积的关系来提高阳极溶出伏安法的灵敏度，是一种有效的方法。     

非常规铜离子敏感碳糊电极的研究

非常规铜离子敏感碳糊电极的研究胡效亚,冷宗周（扬州大学师范学院化学化工系,扬州,２２５００２）关键词电位法,碳糊电极,铜离子,铜离子选择性铜离子选择电极的研究已有大量报道［１～３］,并被广泛用于各种样品的分析［４～６］,但它的响应斜率都在３０ｍＶ／ｄ...     

A Fiber-Optic iron Sensor with Deae Sephadex as a Substrate

Abstract

A fiber-optic sensor for iron (III) has been developed, based on the reflectance intensity change on DEAE sephadex at 460nm. The response time is 10 seconds, the sensor has good sensitivity as well as good reversibility.     

The Rapid and Practical Route to Cu@PCR Sensor: Modification of Copper Nanoparticles Upon Conducting Polymer for a Sensitive Non-Enzymatic Glucose Sensor

In this work, rapid, sensitive, practical, and economical strategy for non-enzymatic glucose sensor has been reported based on a modification of copper nanoparticles upon conducting polymer with high surface area (Cu@PCR). Firstly, PCR conducting polymer electrode (PCR) has been successfully fabricated by electrochemical polymerization of a specially synthesized and characterized star-shaped carbazole derivative. Then copper nanoparticles have been successfully electrodeposited on the PCR as a practical method with cyclic voltammetry. The morphologies of the synthesized materials have been characterized by scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) measurements. The Cu@PCR sensor platform has been displayed a synergistic effect of high catalytical properties of copper nanoparticles and high electroactive properties of PCR towards the glucose oxidation in alkaline medium. The Cu@PCR sensor platform has shown high sensitivity of 847 μAmM⁻¹cm⁻², good stability (10 weeks), a low detection limit of 0.043 μM, and a fast response of 3 s for the non-enzymatic electrochemical detection of glucose. This organic−inorganic hybrid composite sensor is a promising candidate for the fabrication of a highly sensitive and rapid glucose-sensing with the simple preparation procedure and use of a low-cost precursor.     

Fabrication of an optical sensor based on the immobilization of Qsal on the plasticized PVC membrane for the determination of copper(II)

A novel optical sensor has been proposed for sensitive determination of Cu(II) ion in aqueous solutions. The copper sensing membrane was prepared by incorporating Qsal (2-(2-hydroxyphenyl)-3H-anthra[2,1-d]imidazole-6,11-dione) as ionophore in the plasticized PVC membrane containing tributyl phosphate (TBP) as plasticizer. The membrane responds to Cu(II) ion by changing color reversibly from yellow to dark red in acetate buffer solution at pH 4.0. The proposed sensor displays a linear range of 6.3 × 10^?7?1.00 × 10^?4 M with a limit of detection of 3.3 × 10^?7 M. The response time of the optical sensor was about 3?C5 min, depending on the concentration of Cu(II) ions. The selectivity of the optical sensor to Cu(II) ions in acetate buffer is good. The sensor can readily be regenerated by hydrochloric acid (0.1 M). The optical sensor is fully reversible. The proposed optical sensor was applied to the determination of Cu(II) in environmental water samples.     

Facile Synthesis and Characterization of 5-[(3-Methylthiophene-2-yl-methyleneamino)]-2-mercaptobenzimidazole and Its Potentiometric Sensor Application in a Polyvinyl Chloride Membrane for the Determination of Copper(II)

A novel Schiff base designated as 5-[(3-methylthiophene-2-yl-methyleneamino)]-2-mercaptobenzimidazole was synthesized and characterized. A polyvinyl chloride-membrane potentiometric copper(II)-selective sensor was prepared by using the synthesized 5-[(3-methylthiophene-2-yl-methyleneamino)]-2-mercaptobenzimidazole compound. The prepared polyvinyl chloride-membrane copper(II)-selective sensor exhibited very good selectivity and sensitive potentiometric response towards copper(II) ions compared to a wide variety of other cations. The sensor had a fast response time of <5?s, and showed a linear Nerstian behavior to copper(II) ions over a wide concentration range from 1.0?×?10^?5 to 1.0?×?10^?1 mol L^?1 with a slope of 29.2?±?0.7 and correlation coefficient of 0.9998. The prepared polyvinyl chloride-membrane copper(II)-selective sensor was used for 14 weeks without any significant change in its potentiometric response. The potentiometric response of the developed sensor was highly repeatable. Additionally, the developed sensor was used as an indicator electrode for the potentiometric titration of copper(II) ion with ethylenediaminetetraacetic acid. The sensor was also successfully applied to the direct determination of copper(II) ions in tap water, river water, and dam water samples.     

Electrophysical properties of nanocomposites based on poly(p-xylylene) and copper nanoparticles

Poly(p-xylylene)-based nanocomposites containing various amounts of copper have been prepared by vacuum codeposition on a cooled substrate. On the basis of the relationship between the electrical conductivity of composites and the volume content of copper, the percolation threshold has been estimated as 10%. This value coincides with the corresponding parameter derived from the concentration dependence of the electrical resistance temperature coefficient. It has been shown that the conductivity of the nanocomposites increases with the moisture content and their moisture sensitivity decreases with an increase in the content of copper from a concentration of 4%. An analysis of the kinetics of the sensor response measured for various moisture contents has shown that the capacity structure of the samples rearranges during adsorption of water. According to the advanced model, the value of the sensor response is determined by a reduction in the height of the potential barrier between nanoparticles and a change in the fractal characteristics of nanocomposites that results from the adsorption of water molecules.     

长白山白眉蝮蛇蛇毒精氨酸酯酶1的研究Ⅰ.纯化、分子量测定及纯度鉴定

利用离子交换 (DEAESephadexA - 50 )和凝胶过滤层析 (SephadexG - 75)技术首次从长白山白眉蝮蛇蛇毒 (AgkistrodonblomhoffiiUssurensis)中纯化得到了一种精氨酸酯酶纯品。经SDS -聚丙烯酰胺凝胶电泳(SDS -PAGE)以及基质辅助激光解吸电离飞行时间质谱 (MALDI/TOF/MS)鉴定为单一纯蛋白 ,分子量为2 991 8.5± 1 5Da ,为进一步研究其结构与功能提供了可靠的依据。     

A rapid method for isolation and purification of an anticoagulant from Whitmania pigra

Whitmania pigra is common in China and has been used as a traditional Chinese anticoagulant medicine for years, but its effective components are unknown to scientists. In this article we report a rapid method for isolation and purification of an anticoagulant from W. pigra for the first time. An acetone-water extract of W. pigra was subjected to anion-exchange chromatography on a Sephadex DEAE A-50 column, and gel permeation chromatography on Sephadex G-25 and Sephadex LH-20 columns successively, which afforded a fraction with potent anticoagulant activity. An anticoagulant was isolated and purified from this fraction by reversed-phase high-performance liquid chromatography (RP-HPLC). It was identified as a single pure substance by RP-HPLC and sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE). This component was named whitmanin and its molecular weight was determined as 8608 Da by matrix-assisted laser desorption ionization/time-of-flight mass spectrometry (MALDI-TOF-MS).     

普鲁兰多糖的分离纯化及结构鉴定

采用Ｓａｖａｇｅ法，ＤＥＡＥ－纤维素离子交换层析法及Ｓｅｐｈａｄｅｘ Ｇ－１００凝胶过滤法提纯普鲁兰多糖。纯化的普鲁兰多糖的结构经过薄层层析，红外光谱及核磁共振光谱加以鉴定。     

热处理对高温煎煮和低温酶法提制绿茶多糖的影响

采用复合酶法提取和二乙基氨基乙基（DEAE）-纤维素52（DE-52）柱层析纯化制得茶多糖复合物TPC-1;采用煎煮提取、Sephadex G-200柱层析纯化获得茶多糖(TPC)复合物TPC-2。 高效液相凝胶渗透色谱 蒸发光散射检测表明,TPC-1和TPC-2经98 ℃水浴处理5 h后,TPC-1的主要均一性组分TPC-1a裂变为TPC-1a-1和TPC-1a-2 2个组分;圆二色（CD）谱显示TPC-1在194 nm呈现1个正Cotton效应峰,热处理后在216 nm处增加1个正Cotton效应峰;TPC-2经热处理后其中2种均一性组分TPC-2a和TPC-2b未变化,CD谱显示TPC-2在203、215和272 nm处均呈现显著的的正Cotton效应峰,经热处理后前2个峰消失。 98 ℃水浴热处理改变了低温复合酶法提制的茶多糖复合物TPC-1溶液构象和均一性组分的分布,未改变沸水煎煮提制的TPC-2的均一性组分的分布和凝胶色谱行为,但影响了其溶液构象。