香豆素-3-羧酸分子印迹聚合物复合膜对底物的结合及渗透选择性质的研究

在光照和引发剂的作用下, 模板分子香豆素-3-羧酸、 功能单体丙烯酰胺和交联剂乙二醇二甲基丙烯酸酯(EDMA)或三甲氧基丙烷三甲基丙烯酸(TRIM)在聚偏氟乙烯(PVDF)微孔滤膜表面聚合形成分子印迹聚合物复合膜. 用高效液相色谱仪测定了分别以TRIM和EDMA为交联剂制备的分子印迹聚合物膜在不同溶剂中对混合底物的结合和渗透选择性. 结果表明, 以TRIM为交联剂的印迹膜对模板分子具有更高的结合和渗透选择性. 另外, 以乙腈或乙腈/水作为溶剂对分子印迹膜所作的实验和讨论有助于为从复杂样品中分离模板分子奠定理论和实验基础.     

疾病标记物分子印迹技术在分离传感分析中的应用

疾病标记物分子印迹聚合物以疾病标记物为模板分子,可实现低浓度和基底复杂的疾病标记物的高效分离和富集。以疾病标记物分子印迹聚合物为敏感元件构建的传感器,可用于对威胁人类健康的高发病率和高死亡率疾病进行筛查和诊断。本文介绍了分子印迹技术的原理和方法,重点介绍了疾病标记物分子印迹中常用的印迹方法、印迹材料、以及疾病标记物分子印迹聚合物在疾病标记物分离及传感中的应用。     

分子存储材料的设计和思路探讨

从低年级本科生的视角对新型分子存储材料的设计提出设想,尝试以超分子光切换器件为核心构造存储功能分子,结合超分子光化学、超分子光转化和能量转移器件以及超分子电活性材料等方面的知识研究了信息在分子尺度上的传递、记录和表达。并对该方案的可行性、理论模型及其读写过程以何种方式完成进行了分析与探讨。     

分子印迹整体柱快速分离烟酰胺及烟酸

以药物烟酰胺为模板分子,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,甲苯和正十二醇的混合溶液为致孔剂,采用原位聚合法制备了具有特定识别性能和分离能力的分子印迹聚合物,并将其作为高效液相色谱固定相,实现了模板分子与烟酸在2 min内的快速分离。在规格为50 mm×4.6 mm i.d.色谱柱上,以纯水为流动相（流速为7.0 mL/min）、操作温度为室温的色谱条件下,模板分子与烟酸的分离度达1.8。讨论了流动相中有机溶剂含量、醋酸及碱含量和流速对分离的影响。结果表明,原位聚合法制备的整体分子印迹聚合物在以纯水作流动相时对模板分子与其类似物有快速分离能力,这对于体内药物的分离富集研究具有很好的应用前景。     

咪草烟分子印迹聚合物的制备及其选择性吸附性能的研究

以丙烯酸为聚合单体,TMPTA为交联剂,AIBN为引发剂,咪草烟为模板分子,采用在低温光聚合的方法,制备了对咪草烟分子具有选择性识别能力的分子印迹聚合物．通过IR和HPLC表征,咪草烟分子印迹聚合物对咪草烟分子具有良好的识别作用．     

农药丙溴磷分子印迹聚合物微球的制备与结合性能研究

采用分子印迹技术,以丙溴磷为模板分子,分别以α-甲基丙烯酸和丙烯酰胺为功能单体,在乙腈溶液中合成了2种对丙溴磷具有选择性结合能力的分子印迹聚合物.紫外光度法研究表明,模板分子丙溴磷与α-甲基丙烯酸之间的作用强于其与丙烯酰胺之间的作用;扫描电镜的研究则表明以α-甲基丙烯酸为功能单体合成的分子印迹聚合物呈微球形,粒径约为0.5 ～2 μm;利用平衡结合实验研究了不同功能单体制备的聚合物对模板分子的结合能力及其对底物的选择性,经Scatchard模型分析,求出了聚合物的最大表观结合量(Qmax)和平衡离解常数(Kd)分别为49.44 μmol/g 和1.05 mmol/L.研究表明以α-甲基丙烯酸为功能单体合成的分子印迹聚合物对丙溴磷表现出更强的结合能力和更高的选择性.     

咖啡酸分子印迹聚合物的制备及其用于咖啡酸的高效液相色谱分离

以咖啡酸为模板分子,丙烯酰胺为功能单体,在水溶液中合成了咖啡酸分子印迹聚合物,制备了分子印迹聚合物色谱分离柱。试验结果表明:聚合物对印迹分子具有很好的亲和性和特异选择性,以甲醇-水(25+75)混合溶液为流动相,咖啡酸与其相似物绿原酸的分离度达到1.91。     

单氮杂冠醚的合成及性质研究(Ⅱ)──两亲分子的合成及在水溶液中的自组织行为

以酰氯或酸酐与N-(3′-氨苯基)氮杂冠醚反应合成了一系列含长脂链基团的单氮杂冠醚两亲分子。电镜观测结果表明:系列两亲分子在稀溶液中均能自组织稳定的以双分子膜为基本结构的囊泡,其大小为30～150nm,泡壁厚度为5～25nm;并用UV-Vis和微量差示扫描量热研究了双分子膜中分子的聚集态和相变过程。     

环丙沙星分子印迹聚合物的合成及识别性能研究

采用分子印迹技术合成了以环丙沙星为印迹分子,以甲基丙烯酸和4-乙烯基吡啶同时为功能单体的分子印迹聚合物。运用平衡结合实验研究了印迹聚合物的吸附特性和选择识别能力。Scatchard分析表明,在所研究的浓度范围内,分子印迹聚合物中形成了两类不同的结合位点。底物选择实验表明,这种聚合物对环丙沙星呈现高的选择结合能力。     

基于电化学方法研究以铜和银为电极的对苯二甲酸单分子结电导

利用基于电化学跳跃接触的扫描隧道显微镜裂结法(ECSTM-BJ), 通过现场形成金属电极, 对以Cu和Ag为电极的对苯二甲酸单分子结电导进行了测量. 研究结果表明: 利用该方法对所有数据直接线性统计即可得到很好结果; 两种电极下都存在两套高和低电导值, 其中以Cu为电极的单分子结电导高低值分别为11.5和4.0 nS, 而以Ag为电极的单分子结电导分别为10.3和3.8 nS, 高值都约为低值的3倍, 且以Cu为电极的单分子结电导要略大于以Ag为电极的电导, 可归结于电极和分子的耦合不同造成的. 与同样条件下测量得到的烷基链羧酸单分子结电导只存在一套值相比,对苯二甲酸表现出两套电导值, 反应了分子内主链对分子结电导的影响.     

Integrated isotachophoretic preconcentration with zone electrophoresis separation on a quartz microchip for UV detection of flavonoids

A quartz microchip integrated isotachophoretic (ITP) preconcentration with zone electrophoresis (ZE) separation was fabricated using a novel multi-point pressure method featured in normal temperature and lower pressure during bonding process. ITP followed by subsequential ZE of two flavonoids, quercetin and isorhamnetin on the microchip was performed consecutively on the homemade microfluidic workstation with UV detection, resulting in a decreased detectable concentration of 32-fold, compared to the ZE mode only, and their detection limits decreased down to 0.2 microg/mL and 1.2 microg/mL, respectively.     

Coupling microchip electrophoresis with MALDI-TOF-MS based on a freezing technique

A freezing technique protocol was proposed for coupling microchip electrophoresis with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALD1-TOF-MS).The microfluidic flow was frozen immediately after electrophoresis on microfluidic chip and the separated analyte molecules were kept in their zone pattern in the electrophoresis.Then,the frozen-chip was lyophilized and sent into TOF-MS instrument as a MALDI target,and the analyte molecules in the microfluidic channels were subjected to analysis by mass spectrometry.This approach could eliminate sample cross-contamination, providing a new interface for microchip electrophoresis and MALDI-MS.     

Quantitative determination of dopamine in single rat pheochromocytoma cells by microchip electrophoresis with only one high‐voltage power supply

We developed a method for the direct identification of dopamine in single cultured rat pheochromocytoma cells by capillary electrophoresis using an end‐channel carbon fiber nanoelectrode amperometric detector. The operation mode was designed to achieve single‐cell injection and lysis in microfluidic chip electrophoresis with only one high‐voltage power supply. The separation and detection conditions were optimized. Four catecholamines were baseline‐separated and determined with this system, and the cell density and liquid height of the reservoirs were accommodated for single cell loading, docking and analysis. The microchip capillary electrophoresis system was successfully applied to determine dopamine in single cultured rat pheochromocytoma cells.     

On-chip chiral separation based on bovine serum albumin-conjugated carbon nanotubes as stationary phase in a microchannel

A novel method of chiral separation based on protein-stationary phase immobilized in a poly(methyl methacrylate) microfluidic chip was developed. BSA conjugated with the shortened carboxylic single-walled carbon nanotubes (SWNTs) was employed as the chiral selector. Successful separation of tryptophan enantiomers was achieved in less than 70 s with a resolution factor of 1.35 utilizing a separation length of 32 mm. This is the first example of chiral separation based on SWNTs-BSA conjugates as stationary phase immobilized in microchip channel. The stability of the stationary phase in the channel was examined by microchip electrophoresis with laser-induced fluorescence detection. Factors that influenced the chiral separation resolution were examined. Under the optimized conditions, the proposed modified chip revealed adequate repeatability concerning run-to-run. These results show that the use of SWNTs-BSA conjugates within microfluidic channels hold great promise for a variety of analytical schemes.     

集成毛细管电泳芯片研究进展

 介绍了一种多功能化的快速、高效、高灵敏度和低耗的微型装置集成毛细管电泳芯片的发展和最新研究动向 , 39篇。     

整体柱富集技术在微流控芯片系统中的应用

样品预处理技术是微流控芯片技术发展的瓶颈之一。整体材料是近几年在色谱领域发展起来的一种新型色谱填料,具有结构均匀、传质速度快、通透性好、制备过程简单等优点,被广泛用于微流控芯片系统中。该文综述了整体柱富集技术在微流控芯片系统中的应用进展,引用文献80篇。     

Integrated electrokinetically driven microfluidic devices with pH‐mediated solid‐phase extraction coupled to microchip electrophoresis for preterm birth biomarkers

Integration in microfluidics is important for achieving automation. Sample preconcentration integrated with separation in a microfluidic setup can have a substantial impact on rapid analysis of low‐abundance disease biomarkers. Here, we have developed a microfluidic device that uses pH‐mediated solid‐phase extraction (SPE) for the enrichment and elution of preterm birth (PTB) biomarkers. Furthermore, this SPE module was integrated with microchip electrophoresis for combined enrichment and separation of multiple analytes, including a PTB peptide biomarker (P1). A reversed‐phase octyl methacrylate monolith was polymerized as the SPE medium in polyethylene glycol diacrylate modified cyclic olefin copolymer microfluidic channels. Eluent for pH‐mediated SPE of PTB biomarkers on the monolith was optimized using different pH values and ionic concentrations. Nearly 50‐fold enrichment was observed in single channel SPE devices for a low nanomolar solution of P1, with great elution time reproducibility (<7% RSD). The monolith binding capacity was determined to be 400 pg (0.2 pmol). A mixture of a model peptide (FA) and a PTB biomarker (P1) was extracted, eluted, injected, and then separated by microchip electrophoresis in our integrated device with ∼15‐fold enrichment. This device shows important progress towards an integrated electrokinetically operated platform for preconcentration and separation of biomarkers.     

Monolithic media in microfluidic devices for proteomics

Considerable effort has been invested in the development of integrated microfluidic devices for fast and highly efficient proteomic studies. Among various fabrication techniques for the preparation of analytical components (separation columns, reactors, extractors, valves, etc.) in integrated microchips, in situ fabrication of monolithic media is receiving increasing attention. This is mainly due to the ease and simplicity of preparation of monolithic media and the availability of various precursors and chemistries. In addition, UV-initiated photopolymerization technique enables the incorporation of multiple analytical components into specified parts of a single microchip using photomasks. This review summarizes preparation methods for monolithic media and their application as microfluidic analytical components in microchips.     

Fabrication of SU-8 based microchip electrophoresis with integrated electrochemical detection for neurotransmitters

A new SU-8 based microchip capillary electrophoresis (MCE) device has been developed for the first time with integrated electrochemical detection. Embedded electrophoretic microchannels have been fabricated with a multilayer technology based on bonding and releasing steps of stacked SU-8 films. This technology has allowed the monolithic integration in the device of the electrochemical detection system based on platinum electrodes. The fabrication of the chips presented in this work is totally compatible with reel-to-reel techniques, which guarantee a low cost and high reliability production. The influence of relevant experimental variables, such as the separation voltage and detection potential, has been studied on the SU-8 microchip with an attractive analytical performance. Thus, the effective electrical isolation of the end-channel amperometric detector has been also demonstrated. The good performance of the SU-8 device has been proven for separation and detection of the neurotransmitters, dopamine (DA) and epinephrine (EP). High efficiency (30,000-80,000 N/m), excellent precision, good detection limit (450 nM) and resolution (0.90-1.30) has been achieved on the SU-8 microchip. These SU-8 devices have shown a better performance than commercial Topas (thermoplastic olefin polymer of amorphous structure) microchips. The low cost and versatile SU-8 microchip with integrated platinum film electrochemical detector holds great promise for high-volume production of disposable microfluidic analytical devices.