Ricinus communis agglutinin I functionalisation of poly(methyl methacrylate) (PMMA) as a substrate for microfluidic device

We report a functionalisation strategy which is able to generate Ricinus communis agglutinin I (RCA 120) modified PMMA microfluidic device for binding and culturing living cells. The functionalisation is achieved by standard amine-aldehyde (Schiff base) reaction through the cross-linker, glutaraldehyde. To prove the ability of the RCA 120 modified PMMA surface, the PC 12 cell line (rat pheochromocytoma cells) has been captured and cultured by the microfluidic device. In the presence of tunicamycin, the dose/time-dependence on decreasing of binding affinity of RCA 120 modified device with PC 12 cell is also observed. The experimental results demonstrate that the lectin-functionalized microfluidic device can be employed as efficient cell culturing platform, and has a great promise of being used as a powerful tool for monitoring the interaction of drug with living cell.     

基于十八烷基三甲基溴化铵修饰的磁性粒子在线磁性固相萃取-高效液相色谱法测定水样中磺酰脲类农药

采用溶胶-凝胶法制备表面修饰了十八烷基三甲基溴化铵的磁性粒子作为萃取剂，研制了一种在线磁性固相萃取（on-line MSPE）装置，建立了on-line MSPE与高效液相色谱联用测定水样中两种磺酰脲类农药（氯磺隆、苄嘧磺隆）的方法。实验优化了在线磁性固相萃取条件并进行方法学考察，证明该方法具有良好的线性关系（两种目标物的线性相关系数均≥ 0.9997）和较低的检出限（两种目标物的检出限分别为0.32和1.12 μg/L）。将此法用于3种环境水样中两种磺酰脲类农药的检测，水样中均检出氯磺隆，均未检出苄嘧磺隆。两种目标物加标回收率为70.0%~113.4%。该方法高效、简便，在分离富集环境水样中磺酰脲类农药方面有一定的应用前景。     

耐压多样品微量衍生反应装置在气相色谱-质谱联用法分析极性杂环胺中的应用

设计并制作了耐压多样品微量衍生反应装置。在该装置中采用N-(叔丁基二甲基硅烷基)-N-甲基三氟乙酰胺(MTBSTFA,含1%叔丁基二甲基氯硅烷)硅烷化试剂高温衍生极性杂环胺,衍生产物可以直接在气相色谱-质谱联用仪上分析。使用该装置,既可以在比试剂沸点高的温度下实现衍生反应,也可以实现多个微量样品的同时衍生。着重考察了衍生化过程中反应瓶的顶空体积、试剂蒸发面积、温度、时间等实验条件的影响。结果表明,在90 ℃衍生时,与普通衍生装置相比,使用耐压衍生装置可以有效地减小挥发损失,显著增大衍生产量;在150 ℃衍生时,由于试剂挥发损失严重导致普通衍生装置无法使用,而采用耐压衍生装置却可以实现定量衍生,但通过加温加压方式来加快衍生反应速率的效果并不十分明显。     

PNA-Modified Magnetic Nanoparticles and Their Hybridization with Single-Stranded DNA Target: Surface Enhanced Raman Scatterings Study

A 4-pyridyldithiol-derivatized peptide nucleic acid (PNA), which was designed to recognize a specific gene, was attached to 3-mercapropropyloxysilane coated magnetic nanoparticles (MNPs) via a thiol-disulfide exchange reaction. Subsequently, PNA-functionalized magnetic nanoparticles (PMNPs) were prepared. Sequentially the PMNPs were challenged with non-complementary and perfect-match DNA targets. The entire procedure was monitored using surface-enhanced Raman scattering (SERS). The results showed that the PMNPs were able to efficiently hybridize with the perfect-match ssDNA target and showed no affinity towards non-complementary DNA. This approach may provide a means of direct and label-free gene analysis.     

丁烯醛与聚乙烯醇的缩醛化反应机理

化学分析法及碳核磁共振研究表明 ,作为不饱和醛的α 丁烯醛 (巴豆醛 )与聚乙烯醇在水溶液中进行缩醛化时存在着 1,2 加成与 1,4 加成两种反应方式 .此机理不同于只有 1,2 加成方式的聚乙烯醇缩饱和醛化反应 .1,4 加成主要导致聚乙烯醇缩丁烯醛的交联 .还提出了根据化学分析结果计算聚乙烯醇缩丁烯醛的缩醛度以及这两种加成方式的分率的方法     

Synthesis and Spectral Characterization of Some Complexes Derived From N-Benzoyl-N′-Carboxylmethylthiopropylidine Thiourea (Bcmt)

Abstract

New metal complexes derived from the reaction of N-benzoyl-N′-carboxyl methylthiopropylidine thiourea (BCMT) with Cu(II), Co(II), Ni(II), and Fe(III) chloride and/or acetate salts have been synthesized and characterized using elemental analyses, molar conductance, spectral (IR, UV-Vis., mass, ¹H NMR), thermal (TGA, DTG), and magnetic measurements. The IR results showed the modes of coordination in case of mononuclear and binuclear metal complexes. Different types of geometries are suggested on the basis of the spectral and the magnetic data. Also, the ligand field parameters for the metal complexes were calculated. The amounts of the solvents as well as the mechanism of decomposition were proposed using thermal measurements. The results of biological activity of the ligand give us the promise to be effective in tumors treatment.     

INFLUENCE OF TRACES OF WATER ON THE SYNTHESIS AND ELECTROLUMINESCENCE PROPERTIES OF POLY(2-METHOXY, 5- (2'''' -ETHYLHEXYL OXY)- 1, 4-PHENYLENE VINYLENE)

It was found that traces of water in the reaction medium would result in a great increase of gel and a decrease ofmolecular weight of the poly(2-methoxy, 5-(2'-ethylhexyloxy)-1, 4-phenylene vinylene) during the polymerization, whichultimately led to inferior film qualities and device properties. The device (ITO/PEDOT/MEH-PPV/Ba/Al) with MEH-PPVprepared under dry conditions has an external quantum efficiency of above 2.0%.     

New bis(N‐heterocyclic carbene) palladium complex immobilized on magnetic nanoparticles: as a magnetic reusable catalyst in Suzuki‐Miyaura cross coupling reaction

A new bis(N ‐heterocyclic carbene) (NHC) palladium complex supported on silica coated magnetic nanoparticles (MNPs) was prepared using the reaction of synthesized Pd‐NHC complex with MNPs. The Pd‐NHC complex was prepared using the reaction of a hydroxyl‐functionalized bis‐imidazolium ionic liquid. The Pd‐NHC organometallic complex was used as a heterogeneous recyclable and active catalyst in the Suzuki‐Miyaura reaction and various aryl halides were coupled with arylboronic acids in order to synthesize diverse biaryls in good to excellent yields. The prepared catalyst was characterized by use of some different microscopic and spectroscopic techniques including elemental analysis, FT‐IR spectroscopy, diffuse reflectance UV–Vis spectrophotometery, scanning electron microscopy (SEM), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and X‐ray diffraction (XRD). The Pd‐NHC catalyst system is a magnetic reusable catalyst and it can be separated from the reaction mixture using an external magnetic field. The catalyst was reusable in the Suzuki‐Miyaura coupling reaction at least for 6 times without significant decreasing in its catalytic activity.     

大气颗粒物滤膜中极性有机物在线衍生装置的设计与应用

设计制作了一套用于气相色谱-质谱(GC-MS)分析极性有机物的在线衍生装置,并将其应用于大气颗粒物样品中极性有机物的检测.将大气颗粒物滤膜样品置于GC-MS进样口,通过使用套针组件,匀速引入气态衍生试剂N-甲基-Ⅳ-(三甲基硅烷)三氟乙酰胺(MSTFA),使其在衬管内于310℃下与待测物接触,10 min即可完成硅烷化...     

SYNTHESIS AND CHARACTERIZATION OF METAL COMPLEXES WITH AMPICILLIN

Abstract

The reaction, in water, of Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) ions with sodium ampicillinate at room temperature has allowed isolation of dimers with the following general formula [M(amp)Cl]₂ × nH₂O (n = 1.5?3.2). The complexes were characterized by elemental analyses, conductivity measurements, magnetic susceptibilities and spectroscopic methods (IR, Raman, EPR and UV-Visible). A dinuclear structure based on octahedrally coordinated metal ions is proposed.     

SYNTHESIS OF 1,2-DIHYDROXYIMINO-l-PHENYL-3,7-DIAZA-9,10-O-BENZALOCTANE AND ITS COMPLEXES WITH Co(II), Cu(II) AND Ni(II)

Abstract

A novel dioxime, 1,2 dihydroxyimino-3,7-diaza-9,10-O-benzaloctane (LH₂) was prepared by reaction of l,2-0-benzylidene-4-aza-7-aminoheptane and anti-phenylchloroglyoxime in absolute ethanol. Mononuclear complexes with a metal-ligand ratio of 1:2 were prepared with Co(II), Cu(II) and Ni(II). To elucidate the structures of the ligand and complexes, elemental analyses, IR, ¹H NMR and ¹³C NMR spectral data and magnetic susceptibility measurements have been examined.     

Microfluidic device capable of sensing ultrafast chemiluminescence

Based on the principle of liquid core waveguide, a novel microfluidic device with micro-scale detection window capable of sensing flashlight emitted from rapid 1,1′-oxalyldi-4-methylimidazole (OD4MI) chemiluminescence (CL) reaction was fabricated. Light emitted from OD4MI CL reaction occurring in the micro-dimensional pentagonal detection window (length of each line segment: 900.0 μm, depth: 50.0 μm) of the microfluidic device with two inlets and one outlet was so bright that it was possible to take an image every 1/30 s at the optimal focusing distance (60 cm) using a commercial digital camera. Peaks obtained using a flow injection analysis (FIA) system with the micro-scale detection window and OD4MI CL detection show excellent resolution and reproducibility without any band-broadening observed in analytical devices having additional reaction channel(s) to measure light generated from slow CL reaction. Maximum height (H_max) and area (A) of peak, reproducibility and sensitivity observed in the FIA system with the microfluidic device and OD4MI CL detection depends on (1) the mole ratio between bis(2,4,6-trichlorophenyl) oxalate and 4-methyl imidazole yielding OD4MI, (2) the flow rate to mix OD4MI, H₂O₂ and 1-AP in the detection window of the microfluidic device, and (3) H₂O₂ concentration. We obtained linear calibration curves with wide dynamic ranges using H_max and A. The detection limit of 1-AP determined with H_max and A was as low as 0.05 fmole/injection (signal/background = 3.0).     

核壳结构的萘夫西林磁性分子印迹聚合物微球的制备及性能

以表面修饰双键的Fe₃O₄@SiO₂纳米颗粒为基体,以萘夫西林(nafcillin)为模板,甲基丙烯酸(MAA)为单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,偶氮二异丁腈(AIBN)为引发剂,采用三步升温聚合法合成了核壳结构的萘夫西林磁性分子印迹聚合物。采用傅里叶变换红外光谱仪(FT-IR)、透射电子显微镜(TEM)、X射线衍射仪(XRD)和振动样品磁强计(VSM)对制备的印迹聚合物微球进行了表征,得到的磁性印迹聚合物微球的粒径在320 nm左右,大小均匀,分散性较好,可以在外加磁场下与溶剂实现快速分离。对磁性印迹和非印迹聚合物进行了吸附性能研究,结果表明该印迹聚合物微球对模板分子具有很高的吸附容量(50.7 mg/g),特异性识别性能良好(印迹因子为2.46),有望应用于实际样品中萘夫西林残留量的富集分析。     

Poly(basic ionic liquid) coated magnetic nanoparticles: High-loaded supported basic ionic liquid catalyst

A novel poly(ionic liquid) (PIL) coated magnetic nanoparticle was synthesized by distillation-precipitation-polymerization of 1-vinyl-3- ethyl imidazolium in the presence of surface modified magnetic nanoparticles. The resulting catalyst was used as magnetic heterogeneous base catalyst for the synthesis of 4H-benzo[b]pyrans in water. The separation of the catalyst from the reaction mixture was readily achieved by simple magnetic decantation and the catalyst could be easily recycled without appreciable loss of catalytic activity. Because of polymer layers coated the surface of the magnetic nanoparticles, the catalyst has a high loading level of ionic liquid.     

A miniature chemiresistor sensor for carbon dioxide

A carpet-like nanostructure of polyaniline (PANI) nanothin film functionalized with poly(ethyleneimine), PEI, was used as a miniature chemiresistor sensor for detection of CO₂ at room temperature. Good sensing performance was observed upon exposing the PEI–PANI device to 50–5000 ppm CO₂ in presence of humidity with negligible interference from ammonia, carbon monoxide, methane and nitrogen dioxide. The sensing mechanism relied on acid–base reaction, CO₂ dissolution and amine-catalyzed hydration that yielded carbamates and carbonic acid for a subsequent pH detection. The sensing device showed reliable results in detecting an unknown concentration of CO₂ in air.     

Cold fiber solid-phase microextraction device based on thermoelectric cooling of metal fiber

A new cold fiber solid-phase microextraction device was designed and constructed based on thermoelectric cooling. A three-stage thermoelectric cooler (TEC) was used for cooling a copper rod coated with a poly(dimethylsiloxane) (PDMS) hollow fiber, which served as the solid-phase microextraction (SPME) fiber. The copper rod was mounted on a commercial SPME plunger and exposed to the cold surface of the TEC, which was enclosed in a small aluminum box. A heat sink and a fan were used to dissipate the generated heat at the hot side of the TEC. By applying an appropriate dc voltage to the TEC, the upper part of the copper rod, which was in contact to the cold side of the TEC, was cooled and the hollow fiber reached a lower temperature through heat transfer. A thermocouple was embedded in the cold side of the TEC for indirect measurement of the fiber temperature. The device was applied in quantitative analysis of off-flavors in a rice sample. Hexanal, nonanal, and undecanal were chosen as three off-flavors in rice. They were identified according to their retention times and analyzed by GC-flame ionization detection instrument. Headspace extraction conditions (i.e., temperature and time) were optimized. Standard addition calibration graphs were obtained at the optimized conditions and the concentrations of the three analytes were calculated. The concentration of hexanal was also measured using a conventional solvent extraction method (697+/-143ng/g) which was comparable to that obtained from the cold fiber SPME method (644+/-8). Moreover, the cold fiber SPME resulted in better reproducibility and shorter analysis time. Cold fiber SPME with TEC device can also be used as a portable device for field sampling.     

Development and characterization of "push-pull" sampling device with fast reaction quenching coupled to high-performance liquid chromatography for pharmaceutical process analytical technologies

A push-pull sampling system interfaced on-line to high-performance liquid chromatography (HPLC) was developed for micro-volume real-time monitoring of reaction mixtures. The device consists of concentric tubes wherein sample was continuously withdrawn through the outer tube and reaction quenchant continuously delivered through a recessed inner tube. The device allowed sampling rates of 0.1-6.0 μL/min from a reaction vessel and stopped the reaction by passive mixing with quenchant to preserve the conditions observed in the reaction vessel. A finite element model of the system showed that reaction mixtures could be completely mixed with quenchant within 4.3s at a flow rate of 1.0 μL/min. The model also showed that an offset distance of 1mm between the push capillary and sample capillary tips is sufficient to avoid leakage of quenchant/diluent into the bulk sample for push flow rates up to 95% of the pull flow rate. The maximum relative push flow rate was determined to be 90% of the pull flow rate experimentally. Delay between sampling and delivery to the HPLC was from 111±3s to 317±9s for pull flow rates from 1.0 to 3.0 μL/min in agreement with expected delays based on tubing volume. Response times were from 27±1s to 52±6s over the same flow rate range. The sampler was tested to determine the effects of sample viscosity. The sampler was also used to demonstrate periodic sampling capabilities. As a test of the system, it was used to monitor the base-catalyzed hydrolysis of aspirin for 1.5h, demonstrating its utility for monitoring an ongoing reaction.     

Organic light‐emitting device dark spot growth behavior analysis by diffusion reaction theory

Dark spot growth rate tracing experiments performed on an organic light‐emitting device show that moisture entering into the device is relatively properly fitted by Fick's diffusion equation in the substrate/indium tin oxide (ITO)/hole transport layer (HTL)/silver (Ag) structure. It is believed that the moisture is dissolved into the polymer layer, which results in a decrease in the diffusion coefficient in the device with the substrate/ITO/HTL/electroluminescent (EL) polymer/Ag structure. The diffusion and chemical reaction occurring in the cathode layer further decreases the diffusion coefficient in the device with the substrate/ITO/HTL/EL polymer/calcium/Ag structure. Useful parameters, such as diffusion and solubility constants, describing possible mechanisms happening during dark spot growth on organic light‐emitting diode devices are extracted. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 1697–1703, 2001     

Comparison of magnetic properties of DNA-cetyltrimethyl ammonium complex with those of natural DNA

We prepared the DNA-cetyltrimethyl ammonium complex, as well as the same complex intercalated with stable organic free radicals, and studied their magnetic properties by electron magnetic resonance (EMR) spectroscopy and by measuring the magnetization on a superconducting quantum interference device (SQUID). The UV-vis and CD spectra of DNA-quaternary alkyl ammonium complex (DNA--Q+) in organic solvent clearly demonstrated that it retained the double helical B-form conformation. The interhelical spacing of double strand DNA (dsDNA) increased when the counter ions (Na+) of phosphate groups of the natural DNA were replaced with the long alkyl quaternary ammonium groups. The inter-helical distance of DNA-cetyltrimethyl ammonium (CTMA) was 39.1  as confirmed by X-ray diffractometry. In general, the magnetization of the DNA-CTMA complex solid was found to be significantly lower than that of natural DNA. Moreover, intercalation of the complex with stable organic free radicals did not improve magnetization, which again was in marked contrast to natural DNA. EMR spectroscopic behavior of the complex in the solid state also was quite different from that of natural DNA: The unique broad EMR signal of natural DNA in the low field region with g-value greater than 10 disappeared in the DNA-CTMA complex.