用于铅离子检测的Cu-MOF电化学传感器构建及性能研究

通过简单的水热反应制备了一种以铜为中心金属，以2-氨基对苯二甲酸为有机配体的金属有机框架材料(MOF)。用X射线衍射仪、傅里叶变换红外光谱仪、气体物理吸附仪和扫描电子显微镜等对其结构、形貌、比表面积等进行了表征分析。以Cu-MOF为活性材料构建电化学传感器，利用差示脉冲阳极溶出伏安法对样品中Pb²⁺进行检测，系统考察了沉积电位、沉积时间、pH、扫描速率等对目标物检测的影响。实验发现，在最佳条件下，Cu-MOF对3nmol/L～7mmol/L范围内的铅离子表现出良好的线性关系，Pb²⁺的检测限为0.025nmol/L。同时，还研究了传感器的抗干扰能力及对真实样品的检测效果。实验结果表明，Cu-MOF对Pb²⁺的检测显示出良好的灵敏度、选择性、再现性，以及较宽的线性检测范围和较低的检测限，是一种极具应用潜力的电化学传感器活性材料。     

ITO玻璃电致化学发光微流控芯片的低温键合

研究了一种利用商品化的氧化铟锡ITO）玻璃制作一次性电致化学发光微流控芯片的方法．采用光刻和湿法腐蚀ITO（氧化铟锡）层制作微电极;利用同样的方法,在另一片Cr板玻璃上湿法腐蚀微沟道．在玻璃之间夹入PE薄膜作为间质实现芯片的低温键合,采用开孔和预压处理PE薄膜,解决了键合气泡和储液池边缘变形问题．该方法解决了ITO玻璃不耐高温的问题,在120～125℃实现了微通道的有效封接,芯片的键合强度达到0．7MPa．     

一种基于用溶胶凝胶法固定葡萄糖氧化酶的化学发光型葡萄糖传感器

本文利用硅酸乙酯(TEOS)的溶胶凝胶过程对葡萄糖氧化酶(GOD)进行了固定,并制备了不同载体下的GOD酶柱。实验结果表明,GOD可在SiO_2的溶胶凝胶中保持较高的活性。将此酶柱用于流动注射化学发光分析体系,可实现对葡萄糖的在线检测,测定的线性范围为10—1000μmol/L,检出限为0.8μmol/L,RSD为1.6％。此传感器的使用寿命长,测定结果与新国标方法—酶-比色法的测定结果相吻合。     

铅离子对电镀锌钢板黑变的影响

采用实验室的方法，就Ｐｂ＾２＋对电镀锌钢板黑变现象的影响进行了研究，同地利用ＳＥＭ，ＸＲＤ，ＸＰＳ及电化学测试方法对镀锌层的特性和表面膜结构进行了测试，分析，结果表明，Ｐｂ＾２＋对电镀锌钢板黑变的影响极大；为表面膜的主要成分是ＺｎＯ１－Ｘ，本文还讨论了Ｐｂ６３＋对电镀锌钢板黑变影响的机制。     

离子液体电沉积制备Cu掺杂NiO电致变色薄膜及其性能EI北大核心

NiO是一种常见的电致变色材料,元素掺杂改性是改善NiO薄膜电致变色性能的重要方法。以离子液体为介质,采用电沉积法制备Cu掺杂NiO薄膜,并研究Cu元素掺杂对NiO薄膜电致变色性能的影响。结果表明:Cu掺杂NiO薄膜的电致变色性能相较于纯NiO薄膜有明显提升。Cu掺杂含量为6%(原子分数,下同)时,薄膜光调制范围最大,为54.7%,着色效率最高,为61.54 cm^(2)/C,Cu掺杂含量为12%时,薄膜的着褪色响应时间最短,分别达到2.7 s与2.6 s。薄膜的物相结构为面心立方晶相Ni_(1-x)Cu_(x)O,由纳米粒子堆积而成,表面存在大量利于离子扩散的孔隙。     

基于Cu3(HHTP)2薄膜的离子液体电致变色电极

室温离子液体具有宽电化学窗口和良好的环境稳定性, 是电致变色器件的理想电解质。然而传统电致变色材料的晶格间隙较窄, 限制了离子液体中大尺寸离子的扩散, 且大离子反复脱/嵌会破坏传统电致变色材料的结构, 导致性能衰减。金属有机框架材料(MOFs)是一种具有拓扑结构的多孔晶态材料, 有望为离子液体中大尺寸离子的传输提供通道。本工作在导电玻璃表面制备了三亚苯类Cu₃(HHTP)₂ (HHTP=2,3,6,7,10,11-六羟基三苯并菲) MOF薄膜, 并研究了Cu₃(HHTP)₂薄膜在离子液体电解质中电化学和电致变色行为和性能。结果表明, 相对于传统的LiClO₄/PC和NaClO₄/PC电解质, Cu₃(HHTP)₂薄膜在离子液体[EMIm]BF₄中表现出更低的接触电阻和更高的离子扩散效率, 电极的着色/褪色速度得到了显著提高(着色时间由10.3 s缩短至8.0 s, 褪色时间由23.6 s缩短至5.2 s)。同时, Cu₃(HHTP)₂薄膜在[EMIm]BF₄中也具有更高的光调制范围和着色效率。这项工作展现出MOFs/离子液体电化学体系在电致变色领域中的潜在应用价值。     

电致变色材料及器件的研究进展

电致变色材料被认为是目前最有应用前景的智能材料之一,在过去几十年里被广泛研究,相关的电致变色器件也已经上市。本文在总结了各种电致变色材料的变色机理及其成膜方法(重点介绍了本实验室采用射频溅射制备的WO3膜和NiO3膜)的基础上,研究了材料的应用及器件的组装，并对器件组装中所需要的部分其它关键材料进行了介绍。最后对未来电致变色材料及其应用进行了展望。     

电致变色器件用聚合物电解质材料的研究进展

阐述了电致变色器件的工作原理、各层材料组成及其特点，着重讨论了聚合物电解质层的种类和其性能特点，评述了电致变色器件用聚合物电解质材料的最新研究进展，并展望了其应用前景和发展方向。     

固态电致变色薄膜器件的发展现状

本文较系统地综述了固态电致变色薄膜和电致变色薄膜器件的研究发展，过程及现状。并了电致变色薄膜器件所存在的有关问题。     

MWCNTs催化Ru(bpy)_3^(2+)阴极电致化学发光EI北大核心CSCD

采用多壁碳纳米管(MWCNTs)修饰的玻碳(GC)电极作为工作电极(MWCNTs/GC),检测Ru(bpy)2+3水溶液的电致化学发光(ECL)现象。研究发现:当循环伏安(CVs)曲线扫描还原至+0.3V时,可观察到Ru(bpy)2+3的阴极ECL。利用MWCNTs/GC的催化性质可以检测溶液中多巴胺(DA)的含量,其检测限可达1.2×10-11 M。提出MWCNTs在电化学还原过程中产生的中间体可以引发Ru(bpy)2+3的阴极ECL强度。     

Electrochemical DNAzyme sensor for lead based on amplification of DNA-Au bio-bar codes

An electrochemical DNAzyme sensor for sensitive and selective detection of lead ion (Pb(2+)) has been developed, taking advantage of catalytic reactions of a DNAzyme upon its binding to Pb(2+) and the use of DNA-Au bio-bar codes to achieve signal enhancement. A specific DNAzyme for Pb(2+) is immobilized onto an Au electrode surface via a thiol-Au interaction. The DNAzyme hybridizes to a specially designed complementary substrate strand that has an overhang, which in turn hybridizes to the DNA-Au bio-bar code (short oligonucleotides attached to 13 nm gold nanoparticles). A redox mediator, Ru(NH3)6(3+), which can bind to the anionic phosphate of DNA through electrostatic interactions, serves as the electrochemical signal transducer. Upon binding of Pb(2+) to the DNAzyme, the DNAzyme catalyzes the hydrolytic cleavage of the substrate, resulting in the removal of the substrate strand along with the DNA bio-bar code and the bound Ru(NH3)6(3+) from the Au electrode surface. The release of Ru(NH3)6(3+) results in lower electrochemical signal of Ru(NH3)6(3+) confined on the electrode surface. Differential pulse voltammetry (DPV) signals of Ru(NH3)6(3+) provides quantitative measures of the concentrations of Pb(2+), with a linear calibration ranging from 5 nM to 0.1 microM. Because each nanoparticle carries a large number of DNA strands that bind to the signal transducer molecule Ru(NH3)6(3+), the use of DNA-Au bio-bar codes enhances the detection sensitivity by five times, enabling the detection of Pb(2+) at a very low level (1 nM). The DPV signal response of the DNAzyme sensor is negligible for other divalent metal ions, indicating that the sensor is highly selective for Pb(2+). Although this DNAzyme sensor is demonstrated for the detection of Pb(2+), it has the potential to serve as a general platform for design sensors for other small molecules and heavy metal ions.     

Heptadentate Schiff-base based PVC membrane sensor for Fe(III) ion determination in water samples

Tests performed using heptadentate Schiff's base ((tris(3-(thiophenal)propyl)amine (TTA)) toward Fe(III) ions indicated that it could be used as an Fe(III) selective ionophore to be used in a plasticized polymeric membrane sensor. The resulting sensors were found to produce a linear response range of five orders of magnitude with a slope of 19.8 ± 0.3 mV decade^− 1 with a detection limit is 8.3 × 10^− 9 mol L^− 1. The sensor could be used in a pH window of 2.4-4.3 and the response time of the sensor was below 10 s, in addition to its very good Fe(III) selectivity over many mono-,di- and trivalent transition and heavy metal ions. The life time of the electrode was found to be at least 10 weeks.     

Di-tert-butylazodicarboxylate based PVC membrane sensor for Fe(III) ion measurement in pharmaceutical formulation

Preliminary solution study shows the selectivity of di-tert-butylazodicarboxylate (TBADC) toward Fe(III) ions. Due to this selectivity, it was applied as an ionophore for construction of a Fe(III) sensor. The proposed sensor exhibits a wide linear response range with a Nerstian slope of 19.4 ± 0.4 mV decade^− 1 and detection limit of 4.8 × 10^− 8 mol L^− 1. The sensor response is pH independent in the range of 2.3-3.4 and has a fast response time of < 10 s. It also shows very good selectivity to Fe(III) ion over many mono-,di- and trivalent transition and heavy metal ions. The life time of the electrode was at least 10 weeks. The application of the TBADC-based sensor to analysis of Fe(III) ion in a pharmaceutical formulation, and also to the monitoring of Fe(III) ion in mixtures of two, three and four different ions showed satisfactory results.     

Room temperature sensor based on carbon nanotubes and nanofibres for methane detection

Carbon nanotubes and nanofibres deposited by an electrodeposition technique were utilized to fabricate sensor material for the detection of methane. Carbon nanotubes (CNT) and nanofibres were grown on Si(0 0 1) substrate using acetonitrile (1% v/v) and water as electrolyte at an applied d.c. potential ∼20 V. Sensing properties were studied with as-deposited CNT films. It was found that the films showed good sensing properties at room temperature.     

An electric sensor based on the electrogyration effect in a lead tungstate crystal

We present original results of an investigation of the specific features of optical electrochirality (electrogyration) in a lead tungstate crystal. Since this crystal exhibits neither the Pockels effect nor the inverse piezoelectric effect, the electrogyration effect can be used to create a fast-response electric sensor for remote monitoring of high-speed processes in high-voltage electric networks. A fiber-optic sensor prototype has been manufactured using optical elements intended for fiber communications.     

电场法土壤水分传感器研究

合适的土壤水分是作物良好生长和获得高产的条件之一,同时合理灌溉也是节约水资源的有效途径。基于电场法原理研制了测试土壤水分含量的传感器,并利用单片机实现自动控制。通过与烘干法对比研究,该传感器在土壤水分含量小于25%时实验误差小于5%,完全能满足农业生产需要。该传感器使用稳定安全,便于携带,能定点实时监测,精度较高,具有实用价值。     

MnO2纳米材料催化Ru（bpy）3^2＋电致化学发光的研究

利用二氧化锰（MnO2）纳米材料新颖的化学、物理特性,研究其对三联吡啶钌（Ru（bpy）3^2＋的电致化学发光（ECL）的催化作用,结果发现,纳米MnO2材料在温和的条件且较正的电位（＋O．4V（VS．Ag/AgCl））下可以催化Ru（bpy）33^2＋产生阴极ECL。同时推导了其催化机理,为制备一种新型的高灵敏度的ECLSensor奠定了理论基础。     

木质素基树脂的制备及其对重金属离子的吸附性能

以木质素磺酸钠为原料,利用反相悬浮聚合技术,成功制备木质素基树脂.研究了木质素基树脂的制备工艺及其对重金属离子Pb2+、Cd2+的吸附性能.结果表明,优化的聚合条件为:液体石蜡与反应水溶液的相比为3:1、分散剂占有机相百分含量为2%、温度为90℃、盐酸浓度为3mol/L、甲醛占木质素磺酸钠百分含量为9%、聚合时间为2h.30℃时,所制备的树脂对Pb2+、Cd2+的饱和吸附量分别达到33.6523mg/g和30.12mg/g.所制备的木质素基树脂有大量羟基和磺酸基等含氧基团存在,非常有利于它对重金属离子的吸附.木质素基树脂的比表面积为0.0963m2/g,孔容为0.002389cm3/g,平均孔径为99.2208nm,表明该树脂具有大孔树脂的结构特点.     

基于MEMS光线引入器的太阳敏感器技术

太阳敏感器是卫星等航天器上的重要姿态测量部件,其原理是测量太阳光线和敏感器本体主轴的夹角,近而确定卫星的指向.随着MEMS技术和高精度图像传感器技术的发展,将MEMS光线引入器阵列和APS(Active Pixel Sensor)图像传感器技术进行组合,在不增加系统的质量和功耗的情况下通过多个成像阵列来降低系统的随机误差,提高成像中心位置的准确性,从而将太阳敏感器的测量精度提高一个量级.同时采用图像预测提取相关算法(Future Extraction and Image Corre-lation-FEIC),提高了系统的鲁棒性,在部分小孔受到堵塞等干扰情况下,依然保证系统正常工作,精度上基本上不受影响.传统的太阳敏感器一般采用单孔式光线引入器和CCD等方案来实现的,精度比较低.这种新设计思路和实现方法为太阳敏感器系统的可靠性提供了重要保障.     

Ultra-sensitive shape sensor test structures based on piezoresistive doped nanocrystalline silicon

This paper describes the manufacture of a thin skin-like piezoresistor strain-sensing membrane and the miniaturization of dense piezoresistive sensor arrays based on n-type hydrogenated nanocrystalline silicon thin-films (nc-Si:H) deposited on flexible polyimide substrates (PI). The nc-Si:H thin-films, prepared by hot-wire chemical vapor deposition, have a piezoresistive gauge factor of −32.2.Six of the sensors batch-processed on the 15-μm thick membrane, were used in a test structure to track the simulated movement of the head of a bedridden patient. The sensors were glued to both sides of a 3-mm thick acrylic rectangular plate, to collect strain data from the tensile and compressive surfaces of the plate upon bending. The electrical output signal of the sensor was obtained by inserting the sensors into Wheatstone bridge circuits and recording the output voltage of the bridge as a function of the sensor/plate deformation. The results using quarter-, half-, and full-bridge configurations were compared.In order to give a further step toward a shape sensitive electronic textile, nine sensors were glued and interconnected using a machine-sewed conductive thread and preliminary tests on their output response under random loading conditions were performed.