非接触电导检测器的设计与联用技术进展

毛细管电泳中的非接触电导检测技术自1998年问世以来受到了广泛的关注。随着理论研究的深入,检测器的设计不断改进以提高其响应灵敏度,同时使它更便于和已有的仪器设备联用,并应用于微流控芯片电泳中。分析对象也从最初的小无机离子拓展到有机组分和生物大分子,随着商品化检测器的出现,该技术趋于成熟。该文侧重介绍近年来有关该传感器的设计改进、与其它检测器联用、与样品富集技术联合方面的研究和应用进展。     

电泳芯片上非接触电导检测器的研究

非接触电导检测器克服了接触电导检测器的缺点,避免了电极污染,结构简单,易于集成化、微型化,适合芯片毛细管电泳检测.介绍了芯片上非接触电导检测器发展现状,检测原理以及检测池等效电路,并对信号处理电路做初步探讨.     

高效毛细管电泳紫外线与荧光检测器的研究

提出两种可从根本上改变高效毛细管电泳紫外检测器光路状况的方法，使用凹面镜反射式聚光或用组合透镜聚光，使光线在进入毛细管时基本呈垂状态，可使光线以最大光程通过毛细管内的样品溶液。     

微流控电泳芯片微电导检测器的研制

结合电导测量原理以及计算机智能控制技术,设计了一种适合微流控电泳芯片电容耦合非接触电导检测器.文中具体介绍了该检测器硬件组成以及工作原理.该检测器的原理清楚,结构简单,易于微型化、集成化,不污染检测电极,在微型全分析系统中具有十分重要的应用价值.同时,该检测器的信号调理电路不仅可应用于微电导检测,还可配上不同的传感器用于其它测量微弱电流信号的场合.     

毛细管非接触电导检测电极结构对检测性能的影响

毛细管非接触电导检测的检测性能与检测池的电极结构密切相关。目前,电极对检测性能的影响主要从实验的角度进行讨论,缺乏理论分析。本文提出了一种新的非接触电导检测池的等效电路模型。通过对检测池等效电路的仿真,发现检测灵敏度与电极的有效长度有关;屏蔽电极能够很好的消除高激发频率下低待测溶液电导值的输出电流幅值/溶液电导曲线的非线性,提高了待测溶液电导的均匀性和最低检测限,使输出电流幅值/激发频率曲线形成稳定的平台区,很好的提高了检测系统的抗干扰能力。本文对提高非接触电导检测的灵敏度具有一定的理论指导作用。     

集成毛细管电泳芯片的设计

利用ANSYS软件对集成毛细管电泳芯片微沟道内样品流动情况进行模拟,获得了不同进样模式下微沟道的结构与流体流速之间的关系,并以此为依据对芯片整体结构参数进行设计:毛细管沟道最终尺寸为宽度16μm,深度10μm,有效分离长度为3.5cm的圆角转弯形沟道,从而确定整个芯片设计。     

基于ARM的微型毛细管电泳检测仪的设计

设计了基于ARM嵌入式微处理器的毛细管芯片分析仪。系统采用了Linux操作系统,具有在线分析、USB接口、网络传输、小巧轻便、强大的数据采集和处理功能等特点,为毛细管电泳仪的广泛应用提供依据,具有广泛的应用前景。     

毛细管电泳数据工作站的研制及应用

毛细管电泳数据工作站由数据采集卡和系统软件二部分组成，由于在软件中采用了最新的分析化学计量学方法（实时、非实时小波分析，样条最小二乘法等）。因此对较大强度的噪声干扰起到了委好的抑制作用。应用了安培检测器的毛细管电泳数据记录结果表明，工作站比常用函数记录仪的信噪比提高近２０倍，具有良好的应用前景。     

非接触电能传输系统电容补偿机理研究

基于磁耦合谐振非接触电能传输系统中几种不同的电容补偿方式,分析了接收端采用不同补偿方式时反射阻抗与频率的关系,探讨了发射端补偿电容的优化条件,推导了不同补偿方式下系统传输功率的表达式,进一步分析了补偿方式对传输功率的影响。理论分析与仿真结果表明,发射端采用串联补偿、接收端采用并联补偿时,非接触电能传输系统性能最佳。     

毛细管区带电泳的紫外可见光吸收检测

利用紫外可见光吸收方法完成毛细管区带电泳的检测工作，本文就实验装置，实验结果进行了讨论。     

Dual confocal laser-induced fluorescence/moveable contactless conductivity detector for capillary electrophoresis microchip

A new dual simultaneous detector was developed for capillary electrophoresis microchip. Confocal laser-induced fluorescence (LIF) and moveable contactless conductivity detection (MCCD) were combined together for the first time. The two detection systems shared a common detection cell and could respond simultaneously. They were mutually independent and advantageous in analyses of mixtures containing organic and inorganic ions. The confocal LIF had high sensitivity and the MCCD could move along the separation channel and detect in different positions of the channel. The detection conditions of the dual detector were optimized. Rhodamine B was used to evaluate the performance of the dual detector. The limit of detection of the confocal LIF was <5 nM, and that of the MCCD was 0.1 μM. The dual detector had highly sensitivity and could offer response easily, rapidly and simultaneously.     

Microfluidic chips for capillary electrophoresis with integrated electrodes for capacitively coupled conductivity detection based on printed circuit board technology

A simple and low budget microfabrication method compatible with mass production was developed for the integration of electrodes for capacitively coupled contactless conductivity detection (C4D) in Lab on a Chip devices. Electrodes were patterned on a printed circuit board using standard processing. This was followed by lamination-photolithography-lamination to cover the electrodes in dry film photoresist (DFR) using an office laminator. This resulted in a flush, smooth surface on top of the detection electrodes, enabling subsequent integration of a microfluidic network at a distance dictated by the thickness of the DFR (17 μm, 30 μm and 60 μm were used in this work). This process was applied to create two types of detectors, re-usable detectors to be used in combination with a separate microfluidic network and integrated detectors where the microfluidic network is irreversibly sealed to the detector. A poly(dimethylsiloxane) (PDMS) slab containing the microfluidic network was positioned on top of the re-usable detectors to create the PDMS hybrid devices. The integrated DFR devices were created by patterning and sealing the microchannel in DFR using subsequent lamination and lithographic steps. The sensitivity of the C4D made using this new technology for small inorganic cations was between 6 and 20 μM, which is comparable with devices made using significantly more advanced technologies. Where the 17 μm film slightly improved the sensitivity, the use of 30 μm thick insulating films was preferred as these did not impose significant restrictions on the applicable field strengths.     

微型热导检测器温控模块研究

作为微型气相色谱仪(Micro GC)的关键部件的微型热导检测器(Micro TCD),其噪声主要来自于温度波动和气流抖动等因素.从理论上分析了Micro TCD噪声的主要来源,使用COMSOL仿真得到了温度波动对系统噪声的影响,并详述了Micro TCD加热模块的电路部分和算法部分.测试表明:Micro TCD的温度波动约为0.09℃,达到了商用GC控温精度的标准.     

线阵电极电泳芯片与单片机控制系统

介绍了用于生化分析的一种微全分析控制系统,包括电泳芯片的设计制作、微机控制系统以及初步实验结果。新型电泳芯片基于线性阵列电极,可灵活设定分离时间、长度、电压等电泳的各项条件,满足多种分离需求。以C8051F020单片机为控制核心,扩展出大量并行I/O口,并与高压系统实现良好的控制与衔接。突出了单片机系统的高度集成、低功耗、高扩展性等特点,给出了扩展大量I/O口并灵活控制多路高压器件的实例。     

毛细管电泳专家系统知识库的研制与应用

报道了采用Visual Basic6．0研制毛细管电泳专家系统知识库。知识库的构建采用了关系型Access动态数据库和ActiveX数据对象技术(ADO),不仅可大容量收集文献资料,同时支持用户对知识库的即时更新,为分析工作者提供了互动式的在线知识查询和更新平台。对构建知识库所涉及的主要组件进行了详细讨论。     

基于小波变换识别去除毛细管电泳中的奇异峰

提出了一种基于小波变换识别去除毛细管电泳中奇异峰的新方法。电泳图预先去噪,再通过选择合适小波分解,奇异峰可很方便地用一级水平细节识别,然后将其投射到时域中的相应位置去除,去除后的区域采用多项式插值代替。该方法不仅消除了奇异峰,而且有效地降低了背景噪声,正常峰的强度仍保持在90％以上,从而提高了信噪比,降低了检测限。     

Improvement of capillary electrophoresis property for microchannels fabricated by deep X-ray lithography

We fabricated the electrophoresis microchips using the UV polymerization technique. We employed plastic substrates that were suitable for rapid prototyping instead of glass and quartz. A thick UV negative photo resist was used to form molds and poly-dimethylsilozane (PDMS) was polymerized by a thermal curing process on the mold to obtain replica microchips. Electroosmotic flow (EOF) was measured to evaluate the surface. Characteristic differences between UV-fabricated and SR-fabricated microchips were evaluated by electro osmotic flow (EOF) measurement. It was observed that microchannels fabricated by SR lithography show constant peak heights and FWHMs. We also investigated the effect of the change of the channel width along the EOF direction. It is demonstrated that broadening width channel significantly restricts the sample diffusion towards the EOF direction and leads to the high resolusion separation on the PDMS microchips. Thus the advantage of the application of SR lithography to the mold fabrication is also demonstrated.