Application of Sodium Ion Sensor Based on the SnO_2/ITO Glass in the Detection of Rinsing Solution for Contact Lenses

This paper presents the studying results of the sodium ion sensor device based on the SnO_2/ITO glass structure in the detection of rinsing solution for contact lenses.The selective membrane contains poly (vinyl chloride) (PVC),bis (2-ethylhexyl) sebacate (DOS),(12-crown-4) methylmalonate (B12C4),and sodium tetrakis (4-fluoropbenyl) borate dehydrate (NaTFBD). The final weight ratios are PVC:DOS:B12C4:NaTFBD=33:66:2:2.In this condition,the sensor has performances with linear sensitivity,short response time,good repeatability and selectivity.The sensor was used to measure the rinsing solution for the contact lenses.Because the experimental results show close to the accurate value for four commercial products,this sensor can preliminary be used in detecting the rinsing solution for the contact lenses.Using this structure and sodium-sensing membrane to construct the sodium sensor is proven successfully in this application.

Electrodeposited Cobalt-Iron Alloy Thin-Film for Potentiometric Hydrogen Phosphate-Ion Sensor

A cobalt-iron alloy thin-film electrode-based electrochemical hydrogen-phosphate-ion sensor was prepared by electrodepositing on an Au-coated Al2O3 substrate from an aqueous solution of metal-salts. The use of a cobalt-iron alloy electrode greatly improved the hydrogen-ion sensor response performance, i.e., the sensor worked stably for more than 7 weeks and showed a quick response time of several seconds. Among the cobalt and iron alloy systems tested, the electrodeposited Co58Fe42 thin-film electrode showed the best EMF response characteristics, i.e., the sensor exhibited a linear potentiometric response to hydrogen-phosphate ion at the concentration range between 1.0 × 10–5 and 1.0 × 10–2 M with the slope of –43 mV/decade at pH 5.0 and at 30℃. A sensing mechanism of the Co-based potentiometric hydrogen-phosphate ion sensor was proposed on the basis of results of instrumental analysis.

Highly Concentrated,Conductive,Defect-free Graphene Ink for Screen-Printed Sensor Application

Conductive inks based on graphene materials have received significant attention for the fabrication of a wide range of printed and flexible devices.However,the application of graphene fillers is limited by their restricted mass production and the low concentration of their suspensions.In this study,a highly concentrated and conductive ink based on defect-free graphene was developed by a scalable fluid dynamics process.A high shear exfoliation and mixing process enabled the production of graphene at a high concentration of 47.5 mg mL^(−1)for graphene ink.The screen-printed graphene conductor exhibits a high electrical conductivity of 1.49×10^(4)S m^(−1)and maintains high conductivity under mechanical bending,compressing,and fatigue tests.Based on the as-prepared graphene ink,a printed electrochemical sodium ion(Na^(+))sensor that shows high potentiometric sensing performance was fabricated.Further,by integrating a wireless electronic module,a prototype Na^(+)-sensing watch is demonstrated for the real-time monitoring of the sodium ion concentration in human sweat during the indoor exercise of a volunteer.The scalable and efficient procedure for the preparation of graphene ink presented in this work is very promising for the low-cost,reproducible,and large-scale printing of flexible and wearable electronic devices.

1-Pyrenecarboxaldehyde thiosemicarbazone:A novel fluorescent molecular sensor towards mercury(Ⅱ) ion

A novel and simple fluorescent molecular sensor,1-pyrenecarboxaldehyde thiosemicarbazone（Hpytsc）,was synthesized.Its higher sensitivity and selectivity to mercury（Ⅱ） ion were studied through absorption and emission channels.The UV-vis spectra show that the increasing mercury（Ⅱ） ion concentrations result in the decreasing absorption intensity.The fluorescence monomer emission of Hpytsc is enhanced upon binding mercury（Ⅱ） ion,which should be due to the 1：1 complex formation between Hpytsc and metal ion.

Two-Dimensional pH Mapping of a Histamine-Stimulated Gastric Mucosa by Using an Ion Image Sensor in the Guinea Pig

In order to examine the hydronium ion （proton）-releasing functions in cells, [pH]out （extracellular pH） was measured using an ion image sensor composed of a 2D （two-dimensional） array of potential sensitive pixels. Using gastric tissues prepared from the stomach, pH distribution was observed during the histamine stimulation. The 2D distribution of [pH]out in the gastric tissues showed clear differences between the mucosal sides and the serous side. Even before the histamine stimulation, the mucosal side of the gastric mucosa showed a slightly lower pH than that of serous side. In the mucosal side, [pH]out decreased after the onset of the stimulation. The ion image sensor was capable of visualizing [pH]out in the gastric tissues. The present chemical-sensing technique realized a label-free microscopic assessment of the 2D distributions of biologically interesting substances, and consequently, [pH] out imaging via chemical microscopy has a future potential in medical fields for endoscopic analysis of gastric ulcers.

An ionic liquid supported CeO_2 nanoparticles-carbon nanotubes composite-enhanced electrochemical DNA-based sensor for the detection of Pb^(2+)

An electrochemical sensor incorporating a signal enhancement for the determination of lead （II） ions （Pb2＋） was designed on the basis of the thrombin-binding aptamer （TBA） as a molecular recog- nition element and ionic liquid supported cerium oxide （CeO2） nanoparticles-carbon nanotubes compo- site modification. The composite comprises nanoparticles CeO2, multi-waU carbon nanotubes （MWNTs） and hydrophobic room temperature ionic liquid （RTIL） 1-ethyl-3-methylimidazolium tetrafluoroborate （EMIMBF4）. The electrochemical sensors were fabricated by immersing the CeOa-MWNTs-EMIMBF4 modified glassy carbon electrode （GCE） into the solution of TBA probe. In the presence of Pb2＋, the TBA probe could form stable G-quartet structure by the specific binding interactions between Pb2＋ and TBA. The TBA-bound Pb2＋ can be electrochemically reduced, which provides a readout signal for quantitative detection of Pb2＋. The reduction peak current is linearly related to the concentration of Pb2＋ from 1.0 ＊ 10-8 M to 1.0 ＊ 105 M with a detection limit of 5 ＊ 109 M. This work demonstrates that the CeOz-MWNTs-EMIMBF4 nanocomposite modified GCE provides a promising platform for immobi- lizing the TBA probe and enhancing the sensitivity of the DNA-based sensors.

Studies on Non-potentiometric Piezoelectric Sensor System for Determination of Vitamin B_1

A piezoelectric sensor responsive to vitamin B 1 was fabricated based on the vitamin B 1 tetraphenylborate ion pair. The general performance characteristics of the sensor are presented here. The proposed sensor showed a wide working pH range, a good sensitivity and selectivity. The response range is between 1 0×10 -7 -4 9×10 -5 mol/L with a detection limit of 8×10 -8 mol/L at pH 4 0. The selectivity should be attributed to the preferential adsorption of the component ion on the membrane/solution interface. The adsorption behavior of vitamin B 1 on the crystal surface was investigated with a quartz crystal impedance(QCI) system.

Chemiluminescence flow Sensor for determination of the Ammonium ion

A novel chemiluminescence (CL) sensor for NH4+ combined with flow injection analysis is presented in this paper. It is based on the inhibition effect of NH4+ on the CL reaction between luminol, immobilized electrostatically on an anion-exchange column, and hypochlorous acid electrogenerated on-line. The sensor responds linearly to NH4+ concentration in 1.0x10(-6)-4.0x10(-9) g/ml range. A complete analysis could be performed in 1 min. The system is stable for 200 determination.

基于QCM的工业废水中重金属检测

锌离子(Zn^(2+))的检测涉及到食品,水土环境,人体病理等多方面人类安全问题,越发受到国内外学者的关注。为方便且准确地检测排放污水中Zn^(2+)是否达标,采用涂覆能够特异性吸附Zn^(2+)的含醚键离子交换树脂薄膜到石英晶体微天平(QCM)电极上,制备了重金属传感器。通过测量QCM的共振频移,研究了传感器的选择特性,检测精度,检测响应时间和重复性。实验结果表明:制备的涂覆含醚键树脂薄膜石英晶体传感器频率随Zn^(2+)的含量变化明显,检测精确度约为95%,可重复多次检测,检测时长适度。该传感器研究成果在重金属实际检测方面中有潜在的应用前景。

氨基化石墨烯电化学传感器在重金属离子检测中的运用分析

本研究旨在探讨氨基化石墨烯电化学传感器在重金属离子检测中的应用,特别是针对Cd^(2+)和Pb^(2+)的检测。研究内容主要包括氨基化石墨烯(NH_(2)-rGO)、壳聚糖(CS)和聚谷氨酸(Glu)复合材料修饰电极的制备,以及其在电化学检测中的性能评估。通过对不同修饰电极的表征与性能分析,本研究揭示了NH_(2)-rGO/CS/Glu复合材料修饰电极在提高检测灵敏度和选择性方面的显著效果。研究结果表明,相比于裸电极和单一材料修饰电极,NH_(2)-rGO/CS/Glu修饰电极对Cd^(2+)和Pb^(2+)展现出了更高的灵敏度和优异的选择性。此项研究为开发新型高效电化学传感器提供了有价值的参考,对于环境监测和重金属污染控制具有重要意义。

ZIF-8封装AuNCs荧光传感器用于铁离子的检测

介绍一个适合于本科教学使用的综合创新实验,设计合成了一种荧光传感器Au NCs@ZIF-8,并将其用于铁离子(Fe^(3+))的检测。MOFs具有高效吸附、聚集检测物的特点,因此选择将Au NCs封装到ZIF-8中,从而实现目标物的定量检测。封装后,由于Au NCs具有AIE特性,所以Au NCs@ZIF-8的荧光强度明显增强。ZIF-8是一种多孔材料,加入Fe^(3+)后,Fe^(3+)能够进入ZIF-8内部,导致Au NCs的荧光被Fe^(3+)猝灭,成功用于实际水样中Fe^(3+)的检测。尽管该实验步骤复杂并涉及新型纳米材料的合成和表征,但它成功地整合了无机化学、分析化学以及材料化学的相关知识,且操作难度适宜。这为提升学生的动手能力和科技前沿理解提供了一次宝贵的机会。

基于5-氨基烟酸的锰金属有机框架的合成、结构及荧光传感性质

室温下,通过溶液法将5-氨基烟酸(5-Hana)与MnCl_(2)反应,成功合成了一例新的三维Mn(II)金属有机框架[Mn_(2)(5-ana)_(4)(H_(2)O)]n(命名为Mn-MOF)。通过X射线单晶衍射、X射线粉末衍射、元素分析、红外光谱、热重分析、紫外-可见光谱和荧光光谱法对配合物的结构和性质进行表征。结构分析表明,配合物属单斜晶系,具有双节点(2,8)-c配位网络结构,其中[Mn_(2)(CO_(2))_(2)(H_(2)O)]二聚单元作为8-连接节点,5-ana-配体作为2-连接节点。分子范德瓦耳斯表面静电势(ESP)分析表明,5-ana-配体的第一反应位点在羧基氧原子附近,ESP最小值为-143.37 kcal·mol^(-1),第二和第三反应位点分别位于吡啶环和氨基氮原子附近。Mn-MOF常温下具有良好的热稳定性。荧光光谱测试显示配合物在256 nm光激发下的最大发射波长为402 nm。更重要的是,Mn-MOF可以通过荧光猝灭实现对Fe^(3+)的选择性识别,且猝灭效率达到98.71%,可作为潜在的荧光探针分析水溶液中的Fe^(3+)。

锂离子电池热失控气体毒性风险分析方法

为研究锂离子电池热失控气体中主要有毒物质的危害程度,提出一种基于风险评估理论的锂离子电池热失控气体毒性风险分析方法。以点燃参数表征锂离子电池热失控发生概率,利用2种有效剂量分数(FED)方程与气体传感器阵列检测结果,建立锂离子电池热失控气体毒性动力学模型,进而表征气体毒性造成的后果,分析不同荷电状态(SOC)下三元锂离子电池热失控气体的毒性风险。结果表明:高SOC锂离子电池更易进入热失控状态,热失控释放的CO、HF及气体总量随SOC的增加而增加;锂离子电池SOC越高,热失控释放气体毒性风险越大,100%SOC锂离子电池毒性风险约为25%SOC锂离子电池的8倍,需要11倍的新鲜空气稀释才能达到安全浓度。研究结果可为锂离子电池热失控早期预警及气体毒性评价提供数据参考。

循环老化三元锂离子电池热失控气体毒性研究

为研究高能量密度锂离子电池循环老化过程中热失控特性变化及释放气体的毒性危害,对不同循环老化程度的三元锂离子电池进行热滥用实验,利用气体传感器阵列,基于有效剂量分数模型对热失控气体毒性危害进行定量分析。结果表明,高镍含量三元锂离子电池循环性能差,200次循环老化后,电池健康状态低于70%。老化电池更容易进入热失控状态,热失控反应更剧烈但释放能量少,释放气体燃烧效率低。在密闭空间内,电池热失控释放窒息性气体危害性比刺激性气体更高,150次循环老化电池的窒息性气体毒性累积效应比新鲜电池早638 s达到临界值1。随老化程度增加,最终电池的刺激性气体毒性即时效应与气体致死毒性即时效应降低,与新鲜电池相比,100次循环老化后,电池的刺激性气体毒性即时效应降低0.34,气体致死毒性即时效应降低0.19。研究结果可为老化电池安全性评估及热失控预警提供数据支撑。

基于纸基印迹预富集的痕量镉电化学传感器

重金属镉离子(Cd(Ⅱ))是水体质量评价的重要指标之一,本文提出一种基于纸基印迹预富集的痕量镉电化学传感器构建方法,将离子印迹技术、丝网印刷技术、蜡印法和电化学还原有机结合,合成纸基Cd(Ⅱ)印迹聚合物膜(Cd(Ⅱ)-IIP@paper),获得改性后的纸基电极(rGO/SPCE@paper)。通过优化石墨烯沉积时间、预富集时间、模板离子洗脱时间等实验条件,发现在5~100μg/L浓度范围内Cd(Ⅱ)溶出峰电流与浓度表现出良好的线性关系,检出限为0.91μg/L(S/N=3)。结果表明:Cd(Ⅱ)-IIP@paper具有较好的重复性和稳定性,制备的电化学传感器表现出良好的选择性,将其应用于实际水样中Cd(Ⅱ)的检测,回收率在94.0%~104.4%之间,具有较强的实用价值。

基于复合纳米纤维膜的离子传感器制备及其性能

为开发具有高稳定性、高灵敏度的柔性离子传感器,采用静电纺丝法制备聚偏二氟乙烯(PVDF)/离子液体(IL)复合纳米纤维膜,与电极材料组装成三明治结构的离子传感器。探讨了纺丝液质量分数及IL含量对纺丝工艺和纤维膜形貌的影响;其次利用能量色散X射线光谱仪和红外光谱仪表征了复合纳米纤维膜所含元素分布与化学结构;进一步利用柔性传感器测试系统探究了不同IL含量、不同厚度的纳米纤维膜对于传感器性能的影响。结果表明:在PVDF质量分数为18%~19%,且与离子液体量比为2∶1或3∶1时,复合纳米纤维膜表面规整,串珠少,纤维直径分布均匀,带电离子数量增多且分布均匀;随着PVDF/IL纳米纤维膜的厚度增加,离子传感器的检测范围逐渐增大,灵敏度逐渐降低;在聚偏二氟乙烯质量分数为18%,且与离子液体的量比为2∶1时,离子传感器在0~40 kPa的检测范围内具有32.471 pF/kPa灵敏度的压力感测,在5000次加载-循环中保持突出的力学稳定性,并且可应用于分辨人体关节运动的检测。

铅离子印迹电化学传感器的制备及检测性能研究

重金属因其具有高毒性、致癌性和潜在的生物积累性,引发的环境问题受到广泛关注。为精确监测环境中的重金属污染,结合电化学分析和离子印迹技术的优势,构筑了对铅离子的高灵敏电化学传感器。利用铅离子作为模板,采用3-(γ-氨基乙氨基)-丙基-三甲基硅烷作为功能单体,在介孔硅表面,通过共缩聚法制备了离子印迹聚合物,并将其作为电化学传感器的核心识别元件。经过优化碳糊电极的组成,制备了一系列高选择性的离子印迹电化学传感器,并对其电化学行为进行了分析。测试结果表明,所制传感器对铅离子的检测线性范围为10^(-9)~10^(-6) mol/L,且检出限达到1.3×10^(-11) mol/L(信噪比=3)。在对河水和大米等实际样品的检测中,传感器展现了高灵敏性(相对标准偏差为2.5%~7.4%)和高准确性(回收率为98.8%~102.9%),表明其在环境监测和食品安全检测方面具有应用潜力。

一种用于水相介质中Pd^(2+)检测的新型荧光传感器

设计并合成了一种新型四苯乙烯衍生物(TPE-H),该衍生物在THF/H_(2)O(0.5/9.5,体积比)溶液介质中显示出明亮的红色聚集诱导发射(AIE)特性。TPE-H通过荧光“开-关”策略选择性地鉴别Pd^(2+)。该传感器具有出色的选择性和灵敏度,并在很宽的pH范围(4~10)内显示出出色的稳定性。对Pd^(2+)检测的详细研究表明,Pd^(2+)的检出限为9.81×10^(-8)mol/L。通过核磁共振氢谱、傅里叶红外光谱和质谱等测试确认了传感机理。在传感试纸和真实水样测试中,TPE-H对Pd^(2+)具有良好的传感效果,误差较小。该研究不仅报道了一种有效的Pd^(2+)荧光传感器,而且为在复杂环境中原位和实时传感Pd^(2+)提出良好的应用前景。