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研制了一种新型在柱式微流控芯片电导检测装置,利用电解质介导连接分离样品和检测电极,避免了电极的污染和中毒.在芯片的分离通道上设有双T型通道和十字型通道,分别用于进样和检测.检测电极分别置于十字通道口两端的储液池中,电极与芯片相互独立,简化了实验装置,便于电极的更换和清洗.采用缓冲溶液作介导电解质,减小了因两者浓度或种类不同而导致的基线漂移.与非接触电导接触相比,本装置在较低的检测电压(2.5~4.0 V)和频率(700~1700 Hz)范围即可获得相对灵敏的信号.在15 mmol/L MES-His(pH 5.8)的缓冲体系下,K+与Na+的检出限分别为0.5和0.1 μmol/L. 相似文献
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Ludivine Ferey 《Separation & Purification Reviews》2016,45(3):193-226
One of the current trends of separation techniques in analytical chemistry is miniaturization. The aim of miniaturization is to attain better performance, shorter analysis time, and reduced reagent consumption. Capillary Electrophoresis (CE) microchips, the first generation of micro-total analysis systems, are the most used microsystems in food analysis. The scope of this review is to gather and discuss the different applications of such miniaturized devices in this field. Various analytes of food significance such as natural antioxidants, amino acids, proteins, dyes, vanilla flavors, DNA probes, heavy metals, toxins, allergens etc. have been successfully monitored using CE-microchips, either to assess food quality or to ensure food safety. Also, to deal with the high complexity of food matrices, the integration of sample preparation steps onto the chip and the use of new tools from nanotechnology for the detection step have been reported. 相似文献
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An original and simple methodology based on microchip electrophoresis (MCE) in a continuous frontal analysis mode (named frontal analysis continuous microchip electrophoresis, FACMCE) was developed for the simultaneous determination of the binding parameters, i.e. ligand-site dissociation constant (k(d)) and number of binding sites on the substrate (n). This simultaneous determination was exemplified with the interaction between an aptamer and its target. The selected target is a strongly basic protein, lysozyme, as its quantification is of great interest due to its antimicrobial and allergenic properties. A glass microdevice equipped with a fluorescence detection system was coated with hydroxypropylcellulose, reducing the electroosmotic flow and adsorption onto the channel walls. This microdevice allowed the continuous electrokinetic injection of a mixture of fluorescently labelled aptamer and non-labelled lysozyme. By determining the concentration of the free fluorescently labelled aptamer thanks to its corresponding plateau height, mathematical linearization methods allowed to determine a k(d) value of 48.4±8.0 nM, consistent with reported results (31 nM), while the average number of binding sites n on lysozyme, never determined before, was 0.16±0.03. These results seem to indicate that the buffer nature and the SELEX process should influence the number and affinity of the binding sites. In parallel it has been shown that the binding between lysozyme and its aptamer presents two sites of different binding affinities. 相似文献
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A dynamic coating using methylcellulose (MC) and a nonionic detergent (polysorbate 20) was developed, which controlled protein adsorption onto the surface of microchannels on a microchip made of poly(methyl methacrylate) (PMMA). Optimum concentration of polysorbate 20 in combination with the range of MC concentrations controlled the protein adsorption onto the microchannel surface, and increased the solubility of the protein samples while facilitating the injection of high concentrations of MC solutions into the microchannels. Higher concentrations of nonionic detergent increased the EOF mobility as opposed to the electrophoretic mobility and caused the electrophoresis to fail. Nondenaturing microchip electrophoresis of protein samples with molecular masses ranging from 20 to 100 kDa were completed in 100 s. Also, successful separation of a BSA sample and its complex with anti-BSA mAb ( 220 kDa) was achieved on a PMMA microchip. The separation exhibited high reproducibility in both migration time (RSD = 1%) and peak area (RSD = 10-15%). 相似文献
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This review summarizes recent developments and applications of capillary and microchip electroseparation methods in proteomic and peptidomic analyses since the year 2015 to ca. mid 2018. Sample preparation procedures for the removal of interfering components or for pre‐fractionation and preconcentration of proteins and peptides of interest are discussed. The innovations in coupling of capillary or microchip electroseparation methods with different modes of mass spectrometry detection are covered. In addition, significant recent applications of capillary electromigration methods in both bottom‐up and top‐down proteomics as well as in determinations of post‐translational modifications of proteins are presented. Moreover, several examples of the utilization of capillary electromigration methods coupled with mass spectrometry detection for clinical proteomics and peptidomics are described. 相似文献
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自行设计开发了一套便于与电泳芯片集成的一体式柱端安培检测池系统.该系统由整块透明有机玻璃精密加工而成,包括电泳芯片支架和安培检测池两部分,芯片可通过芯片插槽和不锈钢夹具固定在芯片支架上,各种检测用电极可直接通过螺母固定在安培检测池中.以100μmol/L的DA为模式分析物,分别采用直径为100、300和500μm的铂金圆盘电极与表观直径为240μm的碳纤维电极作为工作电极均在该装置上实现了良好组装和高灵敏检测.采用碳纤维工作电极对该系统的检测参数进行了优化.测试结果表明该系统在电化学清洗程序下连续六次测定100μmol/L多巴胺的峰电流相对标准偏差为3.2%,保留时间相对标准偏差为0.5%,DA的检测限为0.4μmol/L(按照S/N=3计).该系统体积小巧,测试稳定,检测灵敏度较高,工作电极更换方便,适合作为芯片电泳柱端安培检测通用平台. 相似文献
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该文基于微芯片电泳-化学发光检测(MCE-CL)平台,以辣根过氧化酶标记的DNA(HRP-DNA)作为信号探针,利用HRP催化鲁米诺和双氧水化学发光反应及目标分子与DNA的杂交反应,结合T7Exo酶辅助信号放大,建立了一种MCE分离辅助双循环化学发光信号放大的新方法。结果显示:优化实验条件下,在1.0×10-14~5.0×10-9mol/L范围内,HIV-DNA的浓度对数值与HIV-DNA的化学发光强度呈良好的线性关系,检出限(S/N=3)为1.6×10-15mol/L,在0.10、0.25、1.0、10(×10-12mol/L)4个加标水平下的回收率为93.0%~103%,相对标准偏差(RSD)为0.50%~3.7%,方法具有较好的准确度,可应用于人血清中HIV-DNA的高灵敏检测。 相似文献
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《Analytical letters》2012,45(18):2883-2891
A capillary electrophoresis microchip coupled with a confocal laser-induced fluorescence (LIF) detector was successfully constructed for the analysis of trace amounts of heavy metals in environmental sources. A new fluorescence dye, RBPhOH, synthesized from rhodamine B, was utilized in a glass microchip to selectively determine copper with high sensitivity. A series of factors including running buffer concentration, detection voltage, and sample loading time were optimized for maximum LIF detector response and, hence, method sensitivity. 相似文献
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In this work, the synergy of one mature example from \"lab-on-chip\" domain, such as CE microchips with emerging miniaturized carbon nanotube detectors in analytical science, is presented. Two different carbon electrodes (glassy carbon electrode (GCE) 3 mm diameter, and screen-printed electrode (SPE) 0.3 mm x 2.5 mm) were modified with multiwalled carbon nanotubes (MWCNTs) and their electrochemical behavior was evaluated as detectors in CE microchip using water-soluble vitamins (pyridoxine, ascorbic acid, and folic acid) in pharmaceutical preparations as representative examples. The SPE modified with MWCNT was the best electrode for the vitamin analysis in terms of analytical performance. In addition, accurate determination of the three vitamins in four different pharmaceuticals was obtained (systematic error less than 9%) in only 400 s using a protocol that combined the sample analysis and the methodological calibration. 相似文献
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CHEN ZhiFeng GAO YunHua WANG Li CHU XiaoGang Chinese Academy of Inspection Quarantine Beijing China Technical Institute of Physics Chemistry Chinese Academy of Sciences Beijing Beijing Institute of Labour Protection Beijing 《中国科学:化学》2010,(1)
A set of integrated end-column amperometric detection system has been developed,onto which an electrophoresis microchip can be conveniently integrated.Finely machined by a piece of transparent organic glass,the system consists of an electrophoresis microchip platform and an amperometric detection reservoir,in which the microchip can be fixed onto the platform by microchip grooves and with stainless steel fixture.Each detection electrode can be directly fixed in the amperometric detection reservoir by screws... 相似文献
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《Journal of separation science》2017,40(7):1583-1588
A fast and effective method was developed to detect domoic acid based upon microchip electrophoresis combined with laser‐induced fluorescence detection. Through study of the gated injection process on the cross channel of the microchip, the low‐voltage mode with relatively longer sample loading time was adopted to reduce the sample discrimination and improve the signal sensitivity. Fluorescein isothiocyanate was used as the derivatizing reagent for domoic acid. Under the optimized conditions, domoic acid was completely separated in 60 s with separation efficiency of 1.35 × 105 m−1. The calibration curve was obtained in the range of 1.0 × 10−9 to 1.0 × 10−7 mol/L, and the detection limit reached 2.8 × 10−10 mol/L. This developed method was successfully applied to analyze domoic acid in real samples. 相似文献