【作者】 潘建章；

【导师】 方群；

【作者基本信息】 浙江大学 ， 分析化学， 2010， 博士

【摘要】 经过近20年的发展,微流控技术因其强大的微流体自动化操控能力和系统的微型化潜力,被众多学者视为分析仪器微型化、自动化发展最具潜力的革命性技术。然而微流控吸收光度分析系统的发展却遭遇到一些问题,如微系统内检测光程短、灵敏度低,吸光度检测器与电子电路和流体驱动部件的综合集成度不高等。第一章首先综述了微流控长光程吸收光度分析系统的研究现状。然后,对当前微流控领域中适用于现场检测和床边检验的微流体驱动技术和试剂预封装技术进行了介绍。第二章报道了一种基于液芯波导技术的全集成手持式微流控光度计。光度计所有部件包括吸光度检测器、液体驱动装置和电路及电池都被集成在12cm×4.5 cm×2.1 cm的仪器内。该光度计将流通池、取样探针和光耦合器集成加工于一根液芯波导毛细管上,显著简化了吸光度检测器结构。首次提出在液芯波导毛细管上加工U型拐弯光耦合器的方法,实现检测光经毛细管侧壁的导入和导出,显著提高了仪器工作的可靠性。采用两只波长为260 nm和280 nm的紫外发光二极管作为光源,实现了双波长的光度检测。该仪器成功应用于微量脱氧核糖核酸试样的纯度和含量测定,以350 nL的试样消耗获得了约15 mm的有效光程。此外,该仪器还被成功用于血清总胆固醇的分析,初步展示了微型手持光度计在床边检验中的应用潜力。第三章报道了一种基于光反射式流通池的全集成手持式微流控光度计。光度计由一次性使用光反射式流通池、重复使用的光电检测器和按压式微泵三部分构成。反射式流通池由涂覆了镜面漆的毛细管构成,以不到400 nL的检测体积获得了近8 mm的有效光程。毛细管流通池内预封装了以油相间隔的试剂溶液、调零溶液、空白溶液和标准溶液四个液段,配合按压泵,实现了微量试样的准确量取和引入、试样试剂的在线混合和各溶液区段的顺序驱动。各区段溶液顺序通过流通池可以依次完成光度计校正、标准溶液吸光度测定和样品吸光度测定等操作步骤,显著简化了吸光度测定的过程。该光度计成本低廉,用一次性毛细管流通池克服了流通池重复使用带来的试样交叉污染问题,用光电检测器实现了高精度的测量,因此在床边检验领域具有很好的应用前景。更多还原

【Abstract】 After twenty years’development, microfluidics has been perceived as one of the most promising revolutionary technologies for on-site analysis and point of care testing (POCT) for its advantage of low sample consumption, rapid analysis, automation and miniaturization of device. Nevertheless, there are still two challenges in the miniaturization of absorption detection systems, including the short path-lengths in miniaturized systems constraining the detection sensitivity, and the lack of fully-integrated absorption spectrometers involving absorption detector, controlling circuit and fluid-handling device.In Chapter One, the development and the recent progress of long path length microfluidic absorption detection systems are reviewed. The fluid driving techniques and reagent preloading techniques suitable for point of care application are also introduced.In Chapter Two, a fully integrated hand-held photometer based on the liquid-core waveguide (LCW) detection principle for nanoliter-scale samples was developed. All components of the photometer including light-emitting diode (LED) light source, LCW flow cell, photodiode detector, dropper pump, electronic circuit, liquid-crystal display screen, and battery were fully integrated into a small-sized (12 x 4.5 x 2.1 cm) instrument. A bent optical coupler was developed to conduct the detection light into or out of the LCW flow cell through its sidewall. This design allowed the sampling probe, input and output optical couplers, and LCW flow cell to be integrated in a single Teflon AF capillary, which significantly simplified system structure, improved working reliability, and reduced sample consumption. Two UV-LEDs were used as light source in the photometer to achieve dual wavelength detection at 260 and 280 nm, which was applied to assess on-site the quality and quantity of DNA samples. The effective optical path length of the photometer was-15 mm with a sample consumption of only 350 nL. The potential of the photometer applied in POCT was also demonstrated in the measurement of total cholesterol in serum samples.In Chapter Three, a totally-integrated handheld photometer based on multi-reflection principle for POCT was developed. The photometer consists of a disposable multi-reflection flow cell, a permanent absorption detector and a dropper pump. The disposable multi-reflection flow cell was composed of a fused silica capillary with specular paint coating. The effective optical path length of the multi-reflection flow cell was -8 mm with a detection volume less than 400 nL. The capillary was also functioned as a liquid cartridge which was preloaded with plugs of reagents segmented by oil. A series of operations including liquid metering, introducing, mixing and driving were realized using the dropper pump, to achieve photometer calibration, and absorbance measurements of sample and standard solutions. The present photometer has advantages of low cost and no cross contamination between different samples, and has potential in the application of POCT.更多还原