一种提高检测长周期光纤光栅折射率灵敏度的方法

本发明公开了一种提高检测长周期光纤光栅折射率灵敏度的方法。通过液相沉积在长周期光纤光栅表面快速可控地制备合适厚度的二氧化锆或五氧化二钽纳米薄膜,提高检测灵敏度。本发明无需昂贵的仪器设备,操作过程简便,节约了调控长周期光纤光栅灵敏度的时间,提高了长周期光纤光栅对折射率的调控效率,降低了制作高灵敏度长周期光纤光栅传感器的成本。     

基于氧荧光猝灭速率法的生化需氧量检测

利用氧荧光猝灭速率的方法,结合自行构建的BOD光纤传感装置进行海水中生化需氧量(BOD)含量检测。考察了四种筛选的海洋耗氧菌种在四甲基硅氧烷(TMOS)、二甲基二甲氧基硅烷(Di Me-DMOS)和聚乙烯醇(PVA)包埋固定情况下,对不同浓度的葡萄糖-谷氨酸(GGA)标准溶液的荧光响应情况。BOD敏感膜的荧光响应在0·2~30mg/L浓度范围内呈良好的线性关系,对2mg/L标准溶液测定的相对标准偏差为2·5%(n=6),响应时间(t95%)为4·0min,BOD敏感膜使用寿命大于12个月。实际海水样品检测表明,利用BOD敏感膜检测得到的结果与国标BOD5方法之间存在较好的一致性。     

一种新的席夫碱敏感膜Cu（Ⅱ）离子选择电极

用对氨基苯甲酸与2-羟基-1-萘甲醛合成了一种新的配体,并制成了高效的敏感膜铜离子选择电极。该电极在含有许多阳离子的情况下对铜离子表现出良好的选择性和灵敏度。它的主要特点是快速响应,在整个过程中响应时间均小于1min。该电极可成功应用于废水中铜离子的检测。     

pH值与湿度的光纤传感器研究

本文采用溶胶凝胶法和包埋法分别将对pH值和湿度敏感的指示剂修饰在光纤纤芯表面,制成了具有较宽检测范围的光纤pH传感器和光纤湿度传感器。通过X射线能谱仪(EDX)对所制备的pH和湿度敏感膜的表面成分进行了分析,并采用光功率计对敏感膜进行了光学检测。结果表明:当pH值在4.5~13的范围内变化时,光输出功率与pH值近似呈线性变化规律;当相对湿度(RH)在25%~80%的范围内变化时,光输出功率与RH值近似呈线性变化规律,并且二者在其检测范围内均具有良好的可逆性。     

温度敏感水凝胶包覆长周期光纤光栅传感器研究

以N-异丙基丙烯酰胺(NIPAM)为单体、N,N'-亚甲基双丙烯酰胺(MBAA)为交联剂、安息香二甲醚(DMPA)为引发剂,利用紫外光引发聚合制备了一系列温度敏感性聚(N-异丙基丙烯酰胺)(PNIPAM)水凝胶,并对其性能进行了测定.结果表明,PNIPAM水凝胶的平衡膨胀比随着交联程度的变化而改变.当交联程度适当时,水凝胶可具有最大的溶胀比.在此研究基础上,利用浸渍提拉法在长周期光纤光栅(LPFG)包层外制备了PNIPAM水凝胶薄膜包覆层.研究了得到的LPFG传感器对温度和湿度的响应性,该类型传感器表现出对温度的灵敏响应性.     

基于纳米CuZSM-5分子筛的传感器用于沙林检测的研究

将纳米ZSM-5或CuZSM-5分子筛作为敏感膜,结合石英晶体微天平(QCM)制备了对神经毒剂沙林(GB)敏感的传感器,研究了硅铝摩尔比和铜离子修饰对毒剂检测性能的影响.结果表明,硅铝摩尔比为25的纳米CuZSM-5分子筛对GB响应最好,并可对GB进行连续多次检测,其灵敏度为19.1 Hz/(mg·m-3),检出限达1.1 mg·m-3(S/N＝3);线性范围为1.5 ～20.0 mg·m-3,线性相关系数为0.995 8,在毒剂检测中具有较强的应用前景.     

功能肽段介导的铜离子荧光传感器的构建及应用

铜离子是导致多种疾病(如阿尔茨海默病、朊病毒病和肌萎缩性侧索硬化症等)的重要因素。当前已有针对铜离子检测的相关报道,但基于多肽与铜离子相互作用的荧光传感器鲜有关注。该文依据淀粉样蛋白与铜离子特异性结合的特点,利用已知的淀粉样蛋白组成单元,设计出能与铜离子有序配位的多肽分子(DDAEGHARHCR)。同时,借助于“多肽-铜离子-钙黄绿素”三元竞争体系,构建出铜离子的荧光恢复性传感器。铜离子能有效地猝灭钙黄绿素的荧光信号。而当向钙黄绿素-铜离子体系引入功能肽段时,肽段凭借更强的结合能力将铜离子夺取出来,极大地恢复体系的荧光信号,进而完成对铜离子的传感检测。在对体系的反应温度、反应时间、pH值、钙黄绿素浓度等实验参数进行优化后,实现了对环境水样中铜离子的高灵敏检测。该方法对铜离子检出限为127 nmol/L,线性范围为0.12~13 μmol/L,具有简单、快速、高效、稳定性好等特点,满足环境水样的检测需求,在水体中铜离子含量的监测与分析方面展现出良好的应用潜力。     

基于三维纳米银修饰电极的硝酸根微型传感芯片研究

研制一种基于金叉指微电极阵列(IDA)的电流型硝酸根离子(NO-3)微传感电极芯片.基于微机电系统(Micro-Electro-Mechanical Systems,MEMS)工艺制备金IDA微电极,通过电化学沉积技术在IDA微电极表面修饰三维枝状结构纳米银敏感膜,利用敏感膜对硝酸根离子良好的电催化还原性能,采用脉冲方波伏安(SWV)电化学测量方法,实现对硝酸根离子在25～1000μmol/L浓度范围内的快速检测,灵敏度达9.5 nA/(μmol/L),线性度为99.98%,检测下限为10μmol/L.考察水体中常见的NO-2,F-,3PO 4-,SO 42-,2CO3-,NH+4,Na+和K+等离子对该传感芯片的干扰性能,传感芯片表现出较好的抗干扰性能.制备的三维枝状结构纳米银修饰IDA微电极可实现水环境(pH 5.0～9.0)中NO-3的电化学检测,对应用于自然水环境中硝酸根离子的现场检测具有积极意义.     

以Sephadex为基质的光纤铜传感器的研究

本文发展了一种新的光纤铜传感器, 用DEAE Sephadex为基质, 通过电价键固定亚硝基红盐作为指示剂, 该传感层在520nm波长下, 反射光强度的变化与铜离子的浓度呈函数关系。用流动法和平衡法对传感器特性进行了研究, 响应时间为5秒,且可逆性好, 已成功应用于自来水和废水中痕量铜离子的直接测定。     

双链铜纳米簇用于铅离子的超灵敏非标记检测

利用聚AT-TA的双链DNA为模板合成铜纳米簇,并作为荧光探针开发了一种荧光生物传感方法用于铅离子的检测。该方法设计是基于铅离子能有效地猝灭铜纳米簇的荧光,当有铅离子存在时,铜纳米簇的荧光强度减弱从而实现对铅离子的灵敏检测。方法用于铅离子的检测,检测时间只需15 min,检出限为5.2 pmol/L,特异性好(没有其它金属离子的干扰)。     

Preparation of electrically conducting particles consisting of a polymer core and a metallic copper shell

Micron-sized composite particles consisting of spherical polymer cores and metallic copper shells were prepared. Basic cupric carbonate was coated on sulfonated polymer particles by pH-controlled hydrolysis of cupric nitrate. The thickness of the coating layer was controlled by the number of polymer particles. Addition of CO₂ during aging increased the shell thickness. Electrically conducting particles were obtained by reduction with hydrogen of the composite particles obtained. Received: 9 August 2000 Accepted: 17 July 2001     

Synthesis and characterization of a metal chelate-bridged quasi-ladder main chain discotic liquid crystal polymer

A metal chelate-bridged quasi-ladder discotic liquid crystal polymer (DLCP) has been prepared by a controlled chelation reaction of cupric ions with β-diketone groups on two adjacent poly(AADK-HMM) chains, synthesized by the hydrosilylation of a bis-allyl groupterminated β-diketone monomer and 1,1,3,3-tetramethylhydrodisiloxane (HMM). X-ray diffraction patterns of the samples annealed in the mesomorphic state or cooled from the isotropic phase demonstrated the existence of an ordered columnar structure on short or long range scales, respectively. The fact that the molecular weight of the cupric complex is approximately twice that of the parent polymer indicates that the quasi-ladder double chain polymer is the predominant product although some terminal defects are present.     

Cupric sulfate–hydrazine system as an initiator of vinyl polymerization. II. Polymerization of methyl methacrylate in aqueous solution in the absence of oxygen

The cupric sulfate–hydrazine system has been used to initiate the aqueous solution polymerization of methyl methacrylate at pH 9.25 in the absence of oxygen. There is no decomposition of hydrazine on the surface of the reduced cupric hydroxide until a flocculant precipitate is formed (cupric sulfate concentration of about 10^?3 mole/1). Below this concentration, the initiating reaction occurs solely in solution, the rate of polymerization decreasing when the reaction mixture becomes depleted in cupric ions. When a suitable surface area of the precipitated polymer is attained, adsorption and decomposition of hydrazine occurs on its surface, causing further initiation of polymerization.     

自由体积与亲水性对环氧涂层防护性能的影响

报道了涂层聚合物自由体积和亲水性对涂层腐蚀防护性能影响的初步研究结果.实验表明,相对于自由体积,树脂的亲水性是决定树脂吸水率的更主要因素.低亲水性涂层腐蚀防护性能的提高主要源自到达涂层/金属界面的水量的显著降低.但由于采用活性酯固化的环氧树脂涂层中水通道的尺寸相对较大,水合离子扩散较容易,因此该类涂层覆盖下的金属基体被润湿部分的腐蚀趋势反而较一般涂层为大.     

Adsorption of univalent and bivalent metal nitrates on hydrous lead dioxide Adsorption behaviour of potassium, cupric, zinc, cadmium and nitrate ions

The individual adsorption behaviour of potassium, cupric, zinc, cadmium and nitrate ions on hydrous lead dioxide (HLD) was investigated. HLD was found to be an amphoteric ion-exchanger with an equi-adsorption point in the vicinity of pH 4.6. For bivalent metal ions, the amount of adsorption increased with pH (at pH > 3) and there was almost 100% adsorption at pH > 6. Both the adsorption capacity and the adsorption affinity on HLD were in the order copper(II) > zinc(II) > cadmium(II).     

Investigation of the fundamental behavior of long-period grating sensors

A new class of fiber optic sensor, long period gratings (LPG) optical sensors, has been investigated. The characteristics of the bare fiber LPG were studied. The LPG response to different refractive index standards, mixtures of methanol and ethanol were observed. The temperature dependence of LPG sensors was determined. A commercial LPG sensor for copper determination was evaluated.     

Preparation and spectroscopic properties of multiluminophore luminescent oxygen and temperature sensor films

A new luminescent oxygen and temperature sensor has been developed that utilizes two luminescent dyes, 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin platinum(II) (PtTFPP, the oxygen sensor) and tris(1,10-phenanthroline)ruthenium(II) dichloride (Ruphen, the temperature sensor). The two dyes are dispersed in an oxygen-permeable polymer binder consisting of a copolymer of 4-tert-butylstyrene (tBS) and 2,2,2-trifluoroethyl methacrylate (p-tBS-co-TFEM). To alleviate energy transfer and other quenching interactions between the two luminescent dyes in the p-tBS-co-TFEM binder, the Ruphen temperature sensor is encapsulated in polyacrylonitrile (PAN) polymer nanospheres that are prepared by coprecipitation of PAN and Ruphen from N,N-dimethylformamide solution. The temperature and air-pressure response of the emission from the sensor film is fully characterized by using emission spectroscopy. The emission from the two luminescent dyes is spectrally well-separated. The intensity of the Ruphen emission varies strongly with temperature (approximately 1.4% degrees C(-1)), whereas the intensity of the PtTFPP emission varies with temperature and air pressure. The two-dye luminescent coating is useful as a pressure-sensitive paint (PSP), where the emission from the Ruphen temperature sensor is used to correct for the temperature dependence of the pressure response of the PtTFPP sensor. To demonstrate the PSP application, a coupon coated with the sensor was imaged using a CCD camera, and the CCD images were analyzed by intensity ratio methods. Spectroscopic studies were also carried out on a sensor that contains three dyes in order to demonstrate the feasibility of including an intensity reference dye along with the temperature and pressure dyes into the sensor.     

The investigation of the behavior of a long period grating sensor with a copper sensitive coating fabricated by layer-by-layer electrostatic adsorption

Sensors based on changes of refractive index in response to sorption of an analyte on the coating or film of a long period grating fiber (LPG) fiber have recently been reported. In most prior work the coating or film swelled during interaction with the analyte. The swelling mechanism produced a kinetic response that slowed both the sensor's time for steady-state measurement and the reversibility of the sensor. Here, the analytical utility of fabricating these nanometer thin films using the layer-by-layer (LBL) electrostatic assembly method is evaluated using Cu^II as the test analyte and Cibacron Blue as the reagent immobilized in the LBL assembly; a generation-4 poly(amidoamine) dendrimer served as the spacer in the assembly. Detection of 1.3 mg Cu^II L⁻¹ was observed when six bilayers comprised the coating. The stable response was achieved with 0.6 mg L⁻¹ in less than 1 min. When 0.1 M HCl was used as the rinsing solution, this LPG sensor was reversible and the signal to similar concentrations of Cu^II reproducible.     

Electrically conductive composite prepared by template polymerization of pyrrole into a complexed polymer

Electrically conducting polymer composite films have been synthesized by the exposure of poly(4-vinylpyridine) complexed with cupric ions to pyrrole and water vapor. To immobilize a stoichiometric amount of the oxidant inside the polymer matrix, the ratio of poly(4-vinylpyridine)/cupric ion = 1.8 was chosen. Polypyrrole was formed in this tailored structure by a template polymerization process. Opaque polymer composite films with electrical conductivity up to 60 (Ω cm)^?1 have been obtained by this method, However, slightly colored transparent composite thin films with a conductivity as high as 50 (Ω cm)^?1 were also produced. The electrically conducting polymer composite films and the metal-polymer complex have been characterized by XPS and IR spectroscopy, elemental analysis, EDX, and scanning electron microscopy. The polymerization process was also followed by use of a quartz crystal microbalance. © 1994 John Wiley & Sons, Inc.     

Free-standing liposomal nanohybrid cerasomes as ideal materials for sensing of cupric ions

Super-stable and free-standing cerasomes with inorganic polyorganosiloxane surfaces were developed for the sensing of Cu(2+) by encapsulating Nile red (NR) dye as a fluorescence reporter. 1,2-Dimynistoyl-sn-glycero-3-phosphatidylethanolamine (DMPE) was incorporated into the cerasomes to serve as the chelating agent for cupric ions. The intraparticle energy transfer from NR to Cu(2+) caused the fluorescence quenching of NR, showing the prospect of these cerasomes as a fluorescence "turn-off" sensor for the detection of trace copper ions.