Synthesis, characteristics and luminescent properties of a new europium(III) organic complex applied in near UV LED

A novel indane based β-diketone with trifluorobutane in the contraposition, 5-acetylindane-4,4,4-trifluorobutane-1,3-dione (HAITFBD) and its europium(III) ternary complex, Eu(AITFBD)₃phen, were designed and synthesized, where phen was 1,10-phenanthroline. The complex was characterized by IR, UV-visible, thermogravimetric analysis (TGA) and photoluminescence (PL) spectroscopy in details. The results show that the Eu(III) complex exhibits high thermal stability, wide and strong excitation bands from 300 nm to 425 nm when monitored at 611 nm, which matches well with the 380 nm-emitting InGaN chips. The complex exhibits intense red emission under excitation of near UV light due to the f-f transitions of the central Eu³⁺ ion. Based on the emission spectrum, the CIE chromaticity coordinates of the LED are calculated as x = 0.63 and y = 0.34, which is suitable to be used as an efficient red phosphor in fabrication of white LEDs. The fluorescence lifetime and the luminescence quantum yield were also measured. The lowest triplet state energy of the primary ligand AITFBD was measured to be 17,730 cm⁻¹, higher than that of the lowest excitation state energy level of the central Eu³⁺ ion, ⁵D₀, and this suggests that the photoluminescence of the complex is a ligand-sensitized luminescence process (antenna effect). Finally, a bright red light-emitting diode was fabricated by coating the Eu(AITFBD)₃phen complex onto a 380 nm-emitting InGaN chip. All the results indicate that Eu(AITFBD)₃phen can be applied as a red component for fabrication of near ultraviolet-based white light-emitting diodes.     

Electrochemical copper (II) sensor based on self-assembled 4-amino-6-hydroxy-2-mercaptopyrimidine monohydrate

A 4-amino-6-hydroxy-2-mercaptopyrimidine monohydrate (AHMP)-based self-assembled monolayer (SAM) was formed on the gold electrode surface. Ellipsometric measurements evidenced the SAM formation on the gold electrode surface. The structural integrity of the modified gold electrode was also characterized by insulating properties of the SAM that were detected by cyclic voltammetry. The results of cyclic voltammetry showed that the SAM, which was formed by assembly of AHMP, was stable but did not completely block the redox-activity of ferrocene and K₃[Fe(CN)₆]/K₄[Fe(CN)₆]. In contrast completely blocked redox-activity was observed after the treatment of AHMP-based SAM with saturated solution of 4-formylphenylboronic acid in 1,4-dioxan. The modified electrodes exhibited a selective response towards Cu(II) ions in the presence of some interfering ions such as Cd(II), Co(II), Fe(II), Ni(II) and Pb(II). This study is the first scientific report on the application of AHMP-modified electrode as a selective Cu(II) sensor in the presence of some interfering cations.     

Highly sensitive chemosensor for Cu(II) and Hg(II) based on the tripodal rhodamine receptor

A new flexible tripodal compound 1 linked with three rhodamine groups as fluorophores and recognition sites was synthesized and its sensing behavior toward metal ions was investigated by UV–vis and fluorescence spectroscopy methods. It exhibited excellent selectivity for Cu(II) over miscellaneous metal ions including Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Zn(II), Cd(II), Al(III), Mg(II), Ca(II), Sr(II), Na(I), and K(I). While the fluorescence of the 1-Cu(II) complex could be enhanced significantly upon the addition of Hg(II) compound 1 may therefore be applicable as an OFF-ON fluorescent chemosensor for Cu(II) and Hg(II).     

Ultra trace mercury(II) detection by a highly selective new optical sensor

This paper presents the development and construction of a sensitive new optical sensor that is highly selective to Hg²⁺ ion in aqueous solution. The sensing element, the newly synthesized (1Z,2Z)-N′¹,N′²-dihydroxy-N¹,N²-dipyridin-2-ylethanediimidamide, incorporated into a plasticized poly(vinyl chloride) membrane, is capable of determining mercury(II) with a high selectivity over a wide dynamic range from 5.78 × 10⁻⁹ to 1.05 × 10⁻³ M at pH 4.0 with a lower detection limit of 1.71 × 10⁻⁹ M. The optode membrane's response to Hg²⁺ is fully reversible and reveals a very good selectivity towards Hg²⁺ ion over a wide variety of other metal ions in solution. Performance characteristics of the sensor evaluated as good reversibility, wide dynamic range, long life span, long-term response stability, and high reproducibility. The proposed optical sensor gives good results for applications in direct determination of mercury(II) in environmental real samples that are satisfactorily comparable with corresponding data from cold-vapor atomic absorption spectrometry.     

聚邻苯二胺在传感器中的应用

根据最新研究文献,系统论述了聚邻苯二胺在生物传感器、湿度传感器、重金属离子传感器等领域的应用.指出聚邻苯二胺具有很好的酶固定性能、离子选择透过性能和耐腐性能等,在分析探测领域显示出广阔的应用前景.     

Designing of MIP-based QCM sensor for the determination of Cu(II) ions in solution

A novel quartz crystal microbalance (QCM) sensor with a high selectivity and sensitivity has been developed for the determination of Cu(II) ions, based on the modification of Cu(II) ion-imprinted polymer (Cu(II)-IIP) film onto a quartz crystal. The performance of the developed MIP-QCM sensor was evaluated and the results indicated that a sensitive MIP-QCM sensor could be fabricated. The obtained MIP-QCM sensor presents high-selectivity monitoring of Cu(II) ions, better reproducibility, shorter response time (6 min), wider linear range (0.001–50 μM) and lower detection limit (8 × 10⁻⁴ μM). The practical analysis of the MIP-QCM sensor confirms the feasibility of Cu(II) determination in wastewater.     

卟啉传感器检测挥发性有机化合物的研究进展

卟啉与金属卟啉具有优良的气敏性能,是检测挥发性有机化合物(VOCs)的理想敏感材料。卟啉与金属卟啉传感器已成功地应用于VOCs的检测。基于不同类型传感器的传感原理,对目前国内外用于VOCs检测的几类卟啉传感器的研究进展进行了分类介绍,并对卟啉传感器在VOCs检测领域的研究方向和发展前景做了展望。     

Fabrication of a highly selective Eu(III) membrane sensor based on a new S–N hexadentates Schiff''s base

A novel potentiometric membrane Eu (III) ion sensor is described based on a new S–N hexadentates Schiff's base, bis(thiophenol)butane2,3-dihydrazone (SNSB). The sensor exhibited a Nernstian response over a concentration range of 1.0 × 10⁻⁵ to 1.0 × 10⁻² M, with a detection limit of 5.0 × 10⁻⁶ M. The best performance was achieved with a membrane composition of 30% PVC, 63% o-nitrophenyloctyl ether (NPOE), 5% SNSB, and 5% (0.010 mmol) potassium tetrakis(p-chlorophenyl) borate (KTpClPB). It was found that in the pH range of 3.0–8.5, the potential response of the sensor was not affected by the pH. Furthermore, the electrode presented satisfactory reproducibility, very fast response time (<5 s), and relatively good discriminating ability for Eu(III) ions with respect to many common cations and lanthanide ions, including sodium, potassium, magnesium, calcium, copper, nickel, cobalt, zinc, lead, lanthanum, cerium, gadolinium, samarium, ytterbium, presidium, terbium, neodymium, holmium, erbium, thulium, lutetium, dysprosium, iron and chromium metal ions. The sensor was applied to the determination of fluoride ions in two mouth wash preparations and binary mixtures.     

基于DPCA方法的传感器故障检测与诊断

针对多传感器的相关时序测量数据,在假设只存在传感器故障的前提下,提出了一种基于动态主成分分析（DPCA）的传感器故障检测方法。根据测量数据建立传感器的DPCA模型,在该模型基础上利用T2和SPE统计量进行传感器的故障检测。同时,将基于主成分分析（PCA）模型的传感器有效度指标SVI推广应用于DPCA模型中。通过对污水处理系统中重要传感器的故障诊断仿真实验表明：该方法能有效地检测和识别出故障传感器。     

Fabrication of a highly selective and sensitive Gd(III)-PVC membrane sensor based on N-(2-pyridyl)-N′-(4-nitrophenyl)thiourea

In this work we report the development of a highly selective and sensitive Gd(III) membrane based on N-(2-pyridyl)-N′-(4-nitrophenyl)thiourea (PyTu4NO₂) as an excellent neutral ion carrier. The Gd(III) sensor exhibits a Nernstian slope of 19.95 ± 0.3 mV per decade over the concentration range of 3.0 × 10⁻⁷ to 1.0 × 10⁻¹ M, and a detection limit of 3.0 × 10⁻⁷ M of Gd(III) ions. The potentiometric response of the sensor is independent of the solution pH in the range of 4.0–9.0. It manifests advantages of low detection limit, fast response time (10 s), and most significantly, very good selectivity with respect to a number of lanthanide ions (La, Ce, Sm, and Eu ions). It can be used at least for a period of 8 weeks without any significant divergences in its potential response. To assess its analytical applicability the proposed Gd(III) sensor was successfully applied as an indicator electrode in the titration of Gd(III) ion solutions with EDTA and for the determination of the fluoride ion in two mouth wash preparations. It was also used for the direct monitoring of Gd(III) ions in binary mixtures.     

Polyphenol-modified glassy carbon electrodes for copper detection

The present work reports the preparation of electrochemically polymerized flavone - luteolin and flavonol - kaempferol modified glassy carbon (GC) electrodes (PolyLut/GC and PolyKae/GC, respectively). Electrochemical polymerization was performed by electrochemical oxidation of luteolin and kaempferol by potential cycling in aqueous media. Cyclic voltammograms of luteolin on the GC electrode indicated one clear oxidation peak at +475 mV, which can be assigned to the oxidation of 3′-hydroxyl and 4′-hydroxyl groups in the B-ring of the luteolin molecule. The cyclic voltammograms of kaempferol on the GC electrode contained two oxidation peaks, one at about +390 mV, which is assigned to the oxidation of 4′-hydroxyl and 3-hydroxyl groups of the B-ring and C-ring of the kaempferol molecule, and second oxidation peak at about +710 mV, which is assigned to the 7-hydroxyl group of the A-ring. The interaction of PolyLut/GC and PolyKae/GC electrodes with copper(II) (Cu(II)) ions were investigated by differential pulse voltammetry (DPV). It was determined that PolyLut/GC and PolyKae/GC electrodes showed sensitivity towards Cu(II) with good reproducibility and stability of analytical signal. The effect of the interfering ions on the voltammetric measurements of Cu(II) was examined.     

多OFC-SAW传感器敏感信息同时提取方法

讨论了多正交频率编码声表面波(OFC-SAW)传感器敏感信息同时提取的方法,设计了多OFC-SAW传感器敏感信息同时提取系统.通过相同中心频率叠加信号片测量值与每个反射OFC信号的关系方程组计算每个OFC反射信号的幅度和延时,通过反射信号的延时差提取敏感信息.经过仿真分析验证了该方法的正确性和有效性.     

Hg2 + 离子传感器的最新研究进展

综述了汞离子传感器的最新研究进展，主要介绍了利用光化学传感器、离子选择电极和生物传感器检测汞离子的状况，重点分析比较了功能材料和传感器特性。在此基础上，介绍了我们的研究情况，通过两个阶段的固相反应合成了汞离子传感器，并且通过激光脉冲沉积(PLD)技术把靶材(汞离子传感器)制备在光寻址电位传感器(LAPS)的表面上，形成薄膜，实现了汞离子传感器的微型化。     

A hybrid biogeography-based optimization algorithm for job shop scheduling problem

In this paper, a hybrid biogeography-based optimization (HBBO) algorithm has been proposed for the job-shop scheduling problem (JSP). Biogeography-based optimization (BBO) is a new bio-inpired computation method that is based on the science of biogeography. The BBO algorithm searches for the global optimum mainly through two main steps: migration and mutation. As JSP is one of the most difficult combinational optimization problems, the original BBO algorithm cannot handle it very well, especially for instances with larger size. The proposed HBBO algorithm combines the chaos theory and “searching around the optimum” strategy with the basic BBO, which makes it converge to global optimum solution faster and more stably. Series of comparative experiments with particle swarm optimization (PSO), basic BBO, the CPLEX and 14 other competitive algorithms are conducted, and the results show that our proposed HBBO algorithm outperforms the other state-of-the-art algorithms, such as genetic algorithm (GA), simulated annealing (SA), the PSO and the basic BBO.     

Potentiometric detection of chromium (III) on the carbon fiber electrode modified by n-hexyl calix[4]resorcinarene

This study was carried out to develop the application of modified carbon fiber electrode in environmental detection, by which chromium (III) ion in water could be electrochemically detected. The modified carbon fiber electrode manifested a linear response within the range of 1.9 × 10⁻⁶–4.6 × 10⁻⁴ mol L⁻¹ (R = 0.9939) and the detection limit was 7.9 × 10⁻⁷ mol L⁻¹. The effect factors were studied to reveal the optimal conditions in the detection of chromium (III) in water, such as pH of total ionic strength adjustment buffer, the concentration of calix[4]resorcinarene, sweep cycles, and so on. The modified carbon fiber electrode, the diameter of which was about 7 μm, was characterized by field emission scanning electron microscopy and electrochemical impedance spectroscopy. Also, the proper mechanism was discussed. The identification of chromium (III) was mainly attributed to the cavity of the calix[4]resorcinarene that the chromium (III) ion could enter into the inner of calix[4]resorcinarene because of the particular structure of calix[4]resorcinarene.     

Development of a new fluorescent sensor based on a triazolo-thiadiazin derivative immobilized in polyvinyl chloride membrane for sensitive detection of lead(II) ions

A new sensor membrane based on a novel triazolo-thiadiazin derivative immobilized in polyvinyl chloride has been developed for the determination of Pb(II) ions that displays excellent performance. The parameters involved in the preparation of the optode and determination of Pb(II) were optimized. Under the optimal conditions, the proposed sensor displays a calibration response for Pb(II) over a wide concentration range of 5.0 × 10⁻⁸ to 3.8 × 10⁻⁴ M with the detection limit of 2.2 × 10⁻⁸ M. In addition to high reproducibility and reversibility of the fluorescence signal, the sensor also exhibits good selectivity over common metal ions. The optode membrane developed is easily prepared, stable, rapid, and simple for the determination of Pb(II). The accuracy of the proposed sensor was confirmed by analyzing standard reference materials of natural water and surface water. The sensor was successfully used for the determination of Pb(II) ions in water samples with satisfactory results.     

Functional testing and characterisation of (bio-)chemical sensors on wafer level

An automated computer-assisted system for the functional testing and characterisation of (bio-)chemical sensors on wafer level is developed and integrated into a commercial prober station. The system enables the identification and selection of “good” sensors on wafer level and thus, allows to avoid further expensive bonding, encapsulation and packaging processes for defective or non-functioning sensor structures. Moreover, a specifically designed flow-through electrochemical microcell offers the possibility of wafer-level characterisation of (bio-)chemical sensors in terms of sensitivity, drift, hysteresis and response time at an early process stage. The system has been exemplarily tested using wafers combining pH-sensitive capacitive electrolyte-insulator-semiconductor structures as well as ion-sensitive field-effect transistors with different geometrical sizes and gate layouts.     

基于分布式光纤传感器的输气管道泄漏检测方法

针对传统方法难以精确诊断输气管道泄漏的难题,提出采用准分布式光纤B ragg光栅(FBG)传感技术实现天然气管道泄漏的在线监测技术。利用一条FBG光缆作为传感器,并行铺设在天然气管道附近,拾取管道由于泄漏、附近机械施工和人为破坏等事件产生的压力和振动信号,通过匹配光栅法和自动识别技术检测管道泄漏并进行定位。实验结果表明:该方法可以实现对天然气管道泄漏进行诊断并定位。     

SAW传感器对神经性毒剂及模拟剂的检测进展

基于压电效应和化学特异选择性的有机敏感材料的声表面波(SAW)传感器,因其具有体积小、响应时间快、选择性好、可集成度高等优点而成为对气体实时、在线检测的重要手段之一。介绍了SAW传感器在神经性毒剂及其模拟剂检测中的应用,重点从SAW传感器测试电路、敏感膜材料、成膜方法及信号处理等方面介绍此领域的研究现状,并对发展趋势进行了展望。     

A device for skin moisture and environment humidity detection

Water content detection is important for our daily life. For environmental detection, the relative humidity is an index for comfortable living atmosphere. For skin health, the water content in stratum corneum is a parameter to diagnose the skin condition. This paper mainly describes a moisture sensor for determination of human skin moisture. The skin moisture sensor is based on the conventional humidity sensor structure (interdigital capacitance, IDC), and the moisture sensor is also sensitive to the environmental humidity. Therefore, the effects of the environment, temperature and humidity, are discussed to find the appropriate operation conditions for skin moisture detection. Besides, the application of the moisture sensor for the environment detection is also described. The IDC structure is fabricated by using printed circuit board (PCB) technology which simplifies the bonding technique and reduces the cost.