An Optical Chemical Sensor Based on Swellable Dicarboxylate Functionalized Polymer Microspheres for pH Copper and Calcium Determination

An optical chemical sensor based on polymer swelling and shrinking has been studied by way of optical transmission. Polyvinylbenzyl chloride cross-linked with divinylbenzene and derivatized as the dicarboxylate was dispersed as microspheres in a hydrogel membrane. The absorbance was measured vs. the wavelength upon exposing the modified membrane to solutions of varying pH (3.0–9.0). At low pH (3.0), the absorbance had the highest value (1.34), while the absorbance decreased significantly (1.10) when the pH was increased to 9.0, indicating polymer swelling.The modified membrane was also used for sensing metal ions, in particular calcium and copper. Complex formation with the dicarboxylate functionality caused the polymer to shrink. This resulted in an increase in absorbance for a concentration ranging from 1.0×10^–3 to 4.0×10^–3M.     

Broad-Range Optical pH Sensor Based on Binary Mixed-Indicator Doped Sol-Gel Film and Application of Artificial Neural Network

Abstract

In this article, we constructed a pH optical sensor based on m-cresol purple/bromocresol green mixed indicators. The sensor possessed different behaviors at various pH values from ?1.04 to 8.70. The observed behaviors were modeled by means of a PC-feed-forward artificial neural network (ANN) with back-propagation training algorithm. The resulting ANN model was used to predict pH values of new measured spectra from unknown solutions. The results showed very good agreement between true and predicted pH values. The sensor revealed no leaching and excellent reversibility. Other advantages of the sensor include rapid response time, long-term stability, reversibility, high sensitivity, and little hysteresis effect.     

模式滤光光纤pH传感器的研究

采用溶胶-凝胶法将邻苯二酚紫涂覆在光纤上,然后将涂好的光纤插入毛细管中,构建新型的模式滤光光纤pH传感器.该传感器的模式滤光信号随pH的增加而降低,且在pH=6.0～9.0范围内有良好的线性关系(R=0.999),响应时间(t95％)为168 s,相对标准偏差为1.95％(n=6);而涂层中未加邻苯二酚紫的光纤传感器对...     

Optical Sensor Arrays Based on Microtiterplate Dimensions

 Multi-analyte and multi-sample sensing requires highly parallel analysis. This paper compares biomolecular interaction analysis based on direct optical detection, with microtiterplate-based assays using labelled reagents. Depending on the method and the application, assays in either a homogeneous or a heterogeneous phase are possible. Their feasibility in different applications is discussed. Two approaches with highly parallel detection devices are demonstrated in the area of environmental analysis as well as in high-throughput screening of drugs. An outlook on the limits of detection using affinity reactions is given. First results of the transfer to nanotiterplates are presented. Received July 14, 1998. Revision November 10, 1998.     

Optical Gas Sensor Fabrication Based on Porphyrin-Anchored Electrostatic Self-Assembly onto Tapered Optical Fibers

Tapered optical fibers with nano-assembled coatings of thicknesses of order tens of nanometres were used for the detection of ammonia gas. The film coating was composed of alternate layers of tetrakis-(4-sulfophenyl) porphine (TSPP) and poly(allylamine hydrochloride) (PAH), which were deposited using the electrostatic self-assembly process (ESA). Exposure of a PAH/TSPP nano-assembled non-adiabatic tapered optical fiber with a waist diameter of 10 µm to ammonia induced significant optical changes in the transmission spectrum of the optical fiber. The fiber optic sensor showed a linear sensitivity to the concentration of ammonia in the range of 10–100 ppm, with response and recovery times less than 100 and 240 sec, respectively. The 3σ limit of detection (LOD) was estimated to be ca. 2 ppm.     

基于表面等离子体激元共振的葡萄糖光化学传感器的研究

采用自行设计组装的表面等离子体激元共振光化学传感器实验装置，在不加其它化学试剂的条件下，研究了传感器对葡萄糖溶液的响应特性。实验结果表明，此传感器测定葡萄糖溶液的稳定性，可逆性良好，响应迅速，使用寿命长。     

Construction of Strontium PVC-Membrane Sensor Based on Salicylaldehyde Thiosemicarbazone

Abstract

This work introduces a unique ionophore for the selective determination of Sr²⁺ ions. The ionophore, salicylaldehyde thiosemicarbazone (ST), presented a high affinity toward the strontium cations. The demonstrated characteristics of the sensor included a linear dynamic range between 1.0 × 10^?6 and 1.0 × 10^?2 M with a near Nernstian slope of 29.4±0.5 mV per decade, a detection limit of 4.8 × 10^?7 M, and a very good selectivity for Sr²⁺ over other cations in a wide pH range (2.8–10.4). The sensor possessed the advantages of short conditioning time, fast response time (< 10 s), and, especially, good selectivity toward the transition and heavy metal ions as well as some mono, di, and trivalent cations. Concerning the electrode lifetime, no considerable potential divergence was noticed for at least 10 weeks. The developed sensor was successfully used as an indicator electrode in the Sr²⁺ titration with EDTA from binary mixtures, and the Sr²⁺ monitoring in mixtures of three and five different ions.     

聚苯胺修饰碳纤维针型复合微pH传感器

由电聚合法用聚苯胺修饰碳纤维电极作为ＰＨ敏感电极。把Ｋ３Ｆｅ（ＣＮ）６／Ｋ４Ｆｅ（ＣＮ）６体系填入医用注射针头内成为参比电极。把经聚苯胺修饰的碳纤维电极安置入该针型参比电极内构成复合针型微ｐＨ传感器。在ＰＨ ２～１２范围内，该传感器呈现超Ｎｅｒｎｓｔ响应，斜率为－７８ ｍＶ／ｐＨ；响应时间<１ｍｉｎ。该传感器成功地应用于在体ｐＨ测定以及水果内微区ｐＨ测定。     

荧光熄灭的苦味酸光化学传感器

苦味酸对固定于聚氯乙烯 (PVC)膜中的N ,N′ 二苄基 3 ,3′,5 ,5′ 四甲基联苯二胺 (TMBD)有可逆荧光猝灭作用 ,据此研制成测定苦味酸浓度的荧光化学传感器。该传感器敏感膜最佳组成为 :5 0mgPVC、1 0 0mg癸二酸二异辛脂 (DOS)和 6.0mgTMBD。在 0 .1 2mol LH2 SO4底液中测定苦味酸 ,其线性响应范围为 2 .1 0×1 0 - 7～ 4 .0 0× 1 0 - 4 mol L ,检出限为 7.8× 1 0 - 8mol L ,其响应时间小于 4 0s。该传感器具有良好的重现性、可逆性和选择性 ,其它常见阴离子和阳离子不干扰测定。本方法用来直接测定合成水样中的苦味酸及间接测定药物辛可宁的含量 ,结果与文献方法一致     

Potentiometric pH response of membranes prepared with various aminated-poly (vinyl chloride) products

The preparation and potentiometric pH response properties of membranes formulated with various aminated-poly(vinyl chloride) (PVC-NH₂) products are described. Products containing secondary and/or primary amino functional groups are obtained by modifying PVC with mono- and/or diamines, respectively. Blank membranes prepared with either type of aminated-polymer exhibit nearly Nernstian potentiometric pH responses over different pH ranges. In general, membranes based on diamino products exhibit pH response over a wider range (5–10.5) than membranes formulated with monoamino products (<8.0). These potentiometric results are used to estimate the basicity of the various primary and secondary amino sites in the membrane phases.Dedicated to Professer W. Simon on the occasion of his 60th birthday     

基于酚藏花红掺杂有机改性溶胶-凝胶膜的亚硝酸盐光学传感器

利用溶胶-凝胶法,研制出基于有机改性溶胶-凝胶膜的亚硝酸盐光学传感器.以甲基三乙氧基硅烷为有机交联剂,与正硅酸乙酯进行水解和缩聚,制备了酚藏花红包埋的有机-无机硅酸盐杂化材料,并采用旋涂法将其涂抹在显微镜载玻片上,形成薄膜.在酸性条件下,NO<'-><,2>与酚藏花红掺杂的溶胶-凝胶膜发生作用,使溶胶-凝胶膜从红色变为...     

All Solid‐State pH Electrode Based on Titanium Nitride Sensitive Film

Titanium nitride was used as pH‐sensitive material to fabricate all solid‐state pH electrode. The fabrication and the response performance of the pH electrode were described in the paper. The TiN film electrode showed a linear response in the pH range of 2–12 with a near‐Nenstian response (?55 mV/pH). The response time was within 1 min, and the electrode had good reproducibility, stability and low sensitivities for different species. Compared with the glass pH electrode, the electrode exhibited some advantages, for example, without activation, rapid response and high mechanical strength. In addition, the electrode performed excellently in a corrosion medium containing F^?(1 M). Electrochemical behaviors of TiN electrode in Britton‐Robinson buffers were studied with Electrochemical Impedance Spectroscopy (EIS).     

A New Chiral Binaphthalene‐Based Fluorescence Polymer Sensor for the Highly Enantioselective Recognition of Phenylalaninol

A new (S)‐binaphthalene‐based polymer ( P ‐ 1 ) was synthesized by the polymerization of 5,5′‐((2,5‐dibutoxy‐1,4‐phenylene)bis(ethyne‐2,1‐diyl))bis(2‐hydroxy‐3‐(piperidin‐1‐ylmethyl) benzaldehyde ( M ‐ 1 ) with (S)‐2,2′‐dimethoxy‐(1,1′‐binaphthalene)‐3,3′‐diamine ( M ‐ 2 ) through the formation of a Schiff base; the corresponding chiral polymer ( P ‐ 2 ) could be obtained by the reduction of polymer P ‐ 1 with NaBH₄. Chiral polymer P ‐ 1 exhibited a remarkable “turn‐on” fluorescence‐enhancement response towards (D )‐phenylalaninol and excellent enantioselective recognition behavior with enantiomeric fluorescence difference ratios (ef) as high as 8.99. More importantly, chiral polymer P ‐ 1 displays a bright blue fluorescence color change upon the addition of (D )‐phenylalaninol under a commercially available UV lamp, which can be clearly observed by the naked eye. On the contrary, chiral polymer P ‐ 2 showed weaker enantioselective fluorescence ability towards the enantiomers of phenylalaninol.     

Gold Nanoparticle-based Colorimetric Sensor for pH Sensing

We present a newly designed colorimetric sensor sensitive to pH value based on a gold nanocomposite composed of gold nanoparticles and pH-sensitive polymer{dodecylthioether end functionalized poly[2-（diethylamino） ethyl methacrylate], poly（DEAEMA）-DDT}. We have shown that this design can produce stable GNP precipitate under weakly basic condition（pH=7.5） and this precipitate can be dispersed in acidic solution（pH=4.0）, due to the 2-（diethylamino） ethyl methacrylate protonated by H＋. The precipitation-dispersion process is reversible and accompanied by distinct color change that are clearly visible to the naked eye. This development may have application in the controlled fabrication of reversible pH-sensitive nanostructures and/or devices.     

盐酸林可霉素分子印迹膜电化学传感器的制备及应用

本文以盐酸林可霉素为目标分子,邻苯二胺为功能单体,采用循环伏安(CV)法,在玻碳电极表面成功制备了盐酸林可霉素聚合膜传感器。应用差分脉冲伏安(DPV)法和CV法对所制传感器的性能进行了研究。实验结果表明,该传感器具有良好的稳定性、重现性、选择性及准确性。用DPV法测定,盐酸林可霉素浓度在6.604×10~(-8)~1.204×10~(-6) mol/L范围内与其峰电流呈线性关系,相关系数r=0.9959,检出限为5.0×10~(-9) mol/L。该方法可用于实际样品的测定。     

键合法制备高亲水性光化学pH传感器敏感膜及性能研究

采用丙烯酰胺为偶合剂,以Fe2+/H2O2为引发剂,将邻甲酚红通过表面接枝聚合固定于交联聚乙烯醇膜表面,制备了一种可用于光化学pH传感器的pH敏感膜。性能测试表明,此膜具有pH响应范围宽(pH7.97～12.26)、响应时间快(<25s)、耐盐性好、可逆重复性及光和贮存稳定性良好,制备方法简单的优点。实验表明,此膜可用于光化学pH传感器。     

Carbon-Filled Polymer Paste Ion-Selective Probes

Abstract

Inexpensive, disposable, carbon-filled polymer paste electrodes activated by a superficial layer of electro-active powder are reported. Sensors for silver, copper, lead and cadmium, halides, nitrate, pH and redox were thus prepared.     

基于碳纳米管修饰电极/鸟嘌呤电化学体系的固体电位型pH传感器

根据鸟嘌呤在短单壁碳纳米管修饰玻碳电极(S-SWCNT/GCE)上发生的电催化氧化特性,及其氧化电位对支持电解质溶液的pH值具有灵敏的响应,制备了以鸟嘌呤为指示剂的固体电位型pH传感器。在优化各种影响因素后,其电位在pH2.0~12.0范围内具有线性响应,回归方程为Epa(V)=-0.0497pH 0.8931。该传感器制备简单,使用方便,响应时间<20 s。在pH响应范围内待测液中离子强度对测定没有影响。酸碱滴定终点具有明显的突跃。对Na 、K 和Ca2 的选择性系数小。已成功地应用于实际样品的测定。     

光控二芳烯化学传感器及其研究进展

有机光致变色材料由于在光学记忆及分子开关器件等领域具有潜在的应用价值而备受关注。在众多有机光致变色系统中,二芳烯类光致变色化合物具有热稳定性好、耐疲劳、响应速度快和灵敏度高等优点,在光电材料和生物医学领域具有广阔的应用前景。近年来,围绕二芳烯构建可调控光化学传感器已成为功能材料领域的一大研究热点。本文主要介绍以二芳烯作为光调控单元合成具有多重调控功能的化学传感器的研究进展,并展望了该领域的应用前景和研究方向。