Bis(2-hydroxyacetophenone)ethylenediimine as a neutral carrier in a coated-wire membrane electrode for lead(II).

A coated-wire ion-selective electrode (CWISE), based on a Schiff base as a neutral carrier, was successfully developed for the detection of Pb(II) in aqueous solution. CWISE exhibited a linear response with a Nernstian slope of 29.4 +/- 0.5 mV/decade within the concentration range of 1.0 x 10(-5) - 1.0 x 10(-1) M lead ion. CWISE has shown detection limits of 5.0 x 10(-6) M. The electrode exhibited good selectivity over a number of alkali, alkaline earth, transition and heavy metal ions. This sensor yielded a steady potential within 10 to 20 s at a linear dynamic range. The electrode was suitable for use in aqueous solutions in a pH range of 2.0 to 5.0. Applications of this electrode for the determination of lead in real samples and as indicator electrode for potentiometric titration of Pb2+ ion using K2CrO4 are reported.     

中性载体可咯化合物应用于银离子电位传感器的研究

研制了一种以5,10,15-三(五氟苯基)可咯[H_3(tpfc)]为活性组分物质、以邻硝基苯辛醚o-NPOE为增塑剂、以四苯硼钠为亲脂性大阴离子添加剂的PVC膜电极(4种物质的质量比为3:3:62:32),电极能斯特斜率为54.8 mV/decade、工作浓度范围为5.1×10~(-6)～0.1 mol/L,pH为4.0～8.0,响应时间不超过30 s,该电极对银离子能抵抗来自Hg~(2+)、Pb~(2+)等离子干扰,表现出较高的选择性.这种传感器可用于对实际矿石样品进行检测.     

Thermal and acid labile polyurethanes as a new class of responsive materials in polymeric nanoparticles and nanocapsules

A new class of polyurethanes has been designed, containing tertiary carbamate groups in the main chain of the polymer, which enable the resulting polymer to degrade completely under acid and thermal treatment. The decomposition temperatures of the polymers were determined by measuring the evolution of carbon dioxide and other decomposition products using TGA‐MS. Until decomposition of the polymer, no glass transition was found. The polymers exhibit excellent solubility in common organic solvents like chloroform and tetrahydrofuran, making them to suitable materials for film formation. From the obtained polymers, nanoparticles were synthesized by the solvent evaporation method combined with the miniemulsion technique. The resulting nanoparticles can be used as intelligent fillers in films and sensors, since they degrade at temperatures of above 180 °C, which can be detected by a color change reaction with ninhydrin. Polymeric nanocapsules were prepared by an interfacial polyaddition reaction from 2,4‐toluene diisocyanate and tertiary diols performed at the droplet's interface in inverse (water‐in‐oil) miniemulsions. These nanocapsules with an encapsulated photoacid generator can act as a release system, whereby an acidic release through irradiation with ultraviolet light can be triggered. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Improved lithium ion-selective electrode based on a lipophilic diamide as neutral carrier

A lithium ion-selective solvent polymeric membrane based on the lipophilic diamide N,N,N',N',-tetraisobutylcyclohexane-cis-l,2-dicarboxylic diamide is described. Selectivity coefficients for lithium ions over other alkali metal ions are greater than 100 and over alkaline earth metal cations are about 1000.     

双水杨醛乙二胺中性载体的锰离子电极的研究

研究以双水杨醛乙二胺[BBG]为中性载体,制备了一种对锰离子(Mn2 )具有优良的电位响应特性的离子选择性电极,其选择性次序为:Mn2 >>Rb ＞Al3 ＞Ca2 ＞Bi3 ＞Cu2 ＞Co2 ＞Fe3 ＞Cd2 ＞Ba2 ＞Ce3 ＞Cr3 ＞La3 ＞Na .该电极在pH 3.0的NaOH-HNO3溶液体系中具有最佳的电位响应,在1.0×10-1mol/L～ 1.0×10-5 mol/L Mn2 浓度范围呈近能斯特响应,斜率为32.0 mV/p Mn2 (25 ℃),检测下限为8.0×10-6 mol/L.采用交流阻抗和紫外光谱分析技术研究了配合物本身的结构对电极电位响应行为的作用机理.将该电极用于实际样品的测定,获得满意的结果.     

Silica-encapsulated nanomagnetic particle as a new recoverable biocatalyst carrier

Enzymes are versatile biocatalysts with major advantages of ultrahigh reaction selectivity and specificity under mild conditions, which currently find increasing applications. However, their applications are often hampered by difficulties in recovery and recycling. As a result, we carried out detailed investigations on the synthesis and characterization of silica-encapsulated iron oxide magnetic nanoparticles of controlled dimension as an enzyme carrier. It is shown that the relatively smaller sized silica-coated magnetic nanoparticle prepared by the microemlusion technique can a carry bulky enzyme, beta-lactamase, via chemical linkages on the silica overlayer without severely blocking the enzymatic active center (which is commonly encountered in conventional solid supports). An activity study by Michalis-Menten kinetics reflects that this new type of immobilization allows enzyme isolation with accessibility as good as free enzyme. The recovery and reusability of the nanoparticle-supported enzyme upon application of magnetic separation are also demonstrated.     

Cyclic peptide nanocapsule as ion carrier for halides: a theoretical survey

In this work, the encapsulations of halide ions including F^?, Cl^?, and Br^? by cyclic peptide nanocapsule as ion carrier (F^?, Cl^?, and Br^? @(Ala4...Ala4)) were investigated using the dispersion corrected density functional theory (DFT) employing CAM-B3LYP functional and the 6–311?+?G (d, p) basis set in the gas phase. The electronic binding energy (E_bind), binding enthalpy (H_bind), and binding Gibbs free energy (G_bind) for each anion were calculated and showed that the stability order of the complexes based on their calculated E_bind is F^??>?Cl^??>?Br^? @(Ala4...Ala4). The calculated value of G_bind for F^? @(Ala4...Ala4) was ??29.77 kcal/mol showing the formation of this complex is thermodynamically favorable while the formation of Br^? @(Ala4...Ala4) is 14.35 kcal/mol which shows that the encapsulation of Br^? is not possible. The calculated value of G_bind for Cl^? @(Ala4...Ala4) was ??0.57 kcal/mol which shows that Cl^? ion can be reversibly stored inside the nanocapsule. The NBO analysis was also performed to investigate the charge transfer between two cyclic peptides in the complexes and also between the anion and the nanocapsule. The NBO analysis showed that the strongest hydrogen bonds between two cyclic peptides are in the complex.     

Heterocirculenes as a new class of organic semiconductors

We report a fabrication of field-effect transistors using the new organic semiconductors octathio[8]circulene and tetrathiotetraseleno[8]circulene . The maximum hole mobility of 9 x 10(-3) cm(2) V(-1) s(-1) is, most likely, limited by one-dimensional growth of and in thin films.     

A PVC membrane pH-sensitive electrode based on methyldioctadecylamine as neutral carrier

A pH-sensitive PVC membrane electrode based on methyldioctadecylamine as neutral carrier has been prepared. It gives linear response over the pH-range 3.0-11.0 and a slope of - 58.4 +/- 0.3 mV/pH (at 20 degrees). The electrode has fairly low resistance and good potential reproducibility. The selectivity and other characteristics of the electrode have been studied.     

Molecular rotors as a class of generally highly active ion transporters

We describe here a class of unconventional ion transporters,molecular rotors that transport ions through a rotating function rather than via traditional carrier...     

异双席夫碱配合物中性载体碘离子电极的研究

研究了以乙二胺、乙酰丙酮缩水杨醛异双席夫碱合钴(Ⅱ)为栽体的PVC膜电极,该电极对I-具有优良的电位响应特性并呈现反Hofmeister选择性行为,其选择性次序为I->Sal->SCN->ClO4->SO32->Br->NO2>Cl->Ac->NO3->SO42-.在pH 2.0的磷酸盐缓冲体系中,对I-在1.0×10-1～1.0×10-7mol/L.浓度范围内呈近能斯特响应,斜率为-50.7 mV/dec(26℃),检出限为3.9×10-8mol/L.采用交流阻抗技术和紫外可见光谱技术研究了电极的响应机理,结果表明配合物中心金属原子的结构以及载体本身的结构与电极的响应行为之间有非常密切的构效关系.将电极初步应用于药物和食盐中碘的分析.     

Dihydropyridazine-appended dibenzosuberenones as a new class of fluorophores: Application to fluoride sensing

Highly fluorescent, novel dihydropyridazine-appended dibenzosuberenone type dye molecules were obtained in a single step from simple compounds using Diels-Alder chemistry. This new fluorophore structure can be used for the construction of fluorescent chemosensors, as exemplified by selective and sensitive fluoride ion sensing. The –N–H protons in these structures are acidic enough to allow for fluoride-induced deprotonation, leading to a significant color change as well as a concomitant fluorescence quenching. These fluorophores possess large Stokes shifts, high quantum yields, and long fluorescence lifetimes; therefore, this study potentially paves the way for the construction of novel dye molecules for use in fluorescent dye applications.     

Copper(II)-selective electrode using 2,2'-dithiodianiline as neutral carrier

Poly(vinyl chloride) membrane electrode, that is highly selective and sensitive to Cu(II) ions, was developed by using 2,2'-dithiodianiline and dibutyl phthalate as carrier and plasticizer, respectively. The electrode exhibits good potentiometric response for Cu(II) over a wide concentration range (5.0x10(-2)-7.0x10(-7) mol l(-1)) with Nernstian slope of 30+/-1 mV per decade. The response time of the electrode is 10 s and it has been used for a period of one month and exhibits good selectivity towards Cu(2+) in comparison to alkali, alkaline earth, transition and heavy metal ions, with no interference caused by Pb(2+), Cd(2+) and Fe(+2) which are known to interfere with many other copper electrodes.     

Novel oxazabicycles as a new class of photochromic colorants

A new photochromic colorant with an oxazabicyclic moiety has been synthesized by an efficient method. It turns pale red upon UV irradiation and undergoes reverse reaction while being heated. This work may open an exciting new avenue for future development of the photochromic dyes with novel molecular structures.     

5,10,15-Tris(pentafluorophenyl)corrole as highly selective neutral carrier for a silver ion-sensitive electrode

A new highly selective silver(I) electrode was prepared with a PVC membrane using 5,10,15-tris(pentafluorophenyl)corrole as an electroactive material, 2-nitrophenyl octyl ether (o-NPOE) as a plasticizer and sodium tetraphenylborate (NaTPB) as an additive in the percentage ratio of 3:3:62:32 (corrole:NaTPB:o-NPOE:PVC, w:w). The electrode exhibited linear response with a near Nernstian slope of 54.8 mV/decade within the concentration range of 5.1 × 10⁻⁶ to 1.0 × 10⁻¹ M silver ions, with a working pH range from 4.0 to 8.0, and a fast response time of <30 s. Selectivity coefficients for Ag(I) relative to a number of interfering ions were investigated. The electrode is highly selective for Ag(I) ions over a large number of mono-, bi-, and tri-valent cations. Common interferents like Hg²⁺ and Cd²⁺ show very low interfering effect on the silver assay, which is valuable property of the proposed electrode. Several electroactive materials and solvent mediators have been compared and the experimental conditions were optimized. The sensor was applied to the determination of silver in real ore samples with satisfied results.     

Bis-dimethylaminobenzaldehyde Schiff-base cobalt(II) complex as a neutral carrier for a highly selective iodide electrode.

A new solvent polymeric membrane electrode based on N,N'-bis-(dimethylaminobenzaldehyde)-glycine cobalt(II) [Co(II)-BDMABG] as a neutral carrier is described, which displays a preferential potentiometric response to iodide ion and an anti-Hofmeister selectivity sequence in the following order: I- > ClO4- > Sal- > SCN- > NO2- > Br- > NO3- > Cl- > SO3(2-) > SO4(2-). The electrode exhibits a near-Nernstian potential linear range of 9.0 x 10(-7)-1.0 x 10(-1) M with a detection limit of 6.8 x 10(-7) M and a slope of -53.0 mV/decade in pH 2.0 of a phosphate buffer solution at 20 degrees C. The response mechanism is discussed in view of the A.C. impedance technique and the UV spectroscopy technique. The electrode was successfully applied to the determination of iodide in Jialing River and Spring in Jinyun Mountains with satisfactory results.     

混合溶剂中性载体镁离子选择性微电极的研究

用氯化石腊和邻硝基苯辛醚为混合溶剂制备中性载体ETH5214的镁离子选择性微电极,相对于钾离子的电位选择性系数较单独以邻硝基苯辛醚为溶剂的ETH5214镁微电极改善0.9个数量级。在纯MgCl~2和在含细胞内典型离子背景的MgCl~2溶液中,响应斜率为Nernst响应,检测下限分别为4×10^-^7mol.dm^-^3和2×10^-^5mol.dm^-^3。在pH3.5-9.5范围内,氢离子对电极的电位响应无影响。测量的重现性良好。电极的实用响应时间(t~9~5)≤3s,有效寿命长于5天。