Chemiluminometric enzyme-linked immunosorbent assays (ELISA)-on-a-chip biosensor based on cross-flow chromatography

A chemiluminometric biosensor system for point-of-care testing has been developed using an immuno-chromatographic assay combined with an enzyme (e.g., horseradish peroxidase) tracer that produces a light signal measurable on a simple detector. Cross-flow chromatography, a method previously investigated by our laboratory, was utilized in order to accomplish sequential antigen-antibody binding and signal generation. This enzyme-linked immunosorbent assay (ELISA) was effectively carried out on a plastic chip that was redesigned to simplify the fabrication process. To enhance the sensitivity, biotin-streptavidin capture technology was employed in preparing an immuno-strip that was then incorporated onto the chip in order to generate the ELISA-on-a-chip (EOC) biosensor. Samples containing cardiac troponin I (cTnI) were analyzed using the EOC. A chemiluminescent signal proportional to the analyte concentration was produced by adding a luminogenic substrate to the tracer enzyme complexed with the analyte on the chip. The luminescent signal was detected in a dark chamber mounted with a cooled charge-coupled device and the signal was converted to optical density for quantification. This EOC biosensor system was capable of detecting cTnI present in serum at concentrations as low as 0.027 ng mL⁻¹, 30 times lower than those measured using the conventional rapid test kit with colloidal gold as the tracer. In addition, the final data was acquired within 30 s after the addition of the enzyme substrate, which was faster than the detection time required when using a colorimetric substrate with the same tracer enzyme.     

Development of a miniature simultaneous MPT spectrometer

An unique miniature simultaneous microwave plasma torch (MPT) atomic emission spectrometer employing linear UV intensified charge-coupled device (ICCD) array detector has been developed and studied preliminarily. The detection limits and precisions of the spectrometer for Ag, Al, Ba, Ca, Cr, Cu, Fe, Mg, Mn, Sr and V by using different CCD exposure times have been determined. An analysis of a practical sample has been carried out. The preliminary results demonstrate that such simultaneous spectrometer has advantages of saving sample and time, especially suitable for use as detector for chromatography and in combination with flow injection systems. Taking analytical figures of merit and portability into accounts, the miniature simultaneous MPT system will have extended application areas and greater competition potential as compared with commercialized scanning MPT spectrometers.     

用毛细管电泳-激光诱导荧光-增强型电荷耦合检测器测定痕量氨基酸

本文对用毛细管电泳－激光诱导荧光－增强型电荷耦合检测器测定氨基酸衍生物进行了研究。考察了荧光黄异疏氰酸酯衍生氨基酸的各种条件。在优化条件下，10－8～10－6mol／L浓度范围内精氨酸与其衍生物的荧光强度呈良好的线性关系，最小可衍生化的精氨酸浓度为5×10－10mol／L。     

Comparison of procedures for correction of matrix interferences in the multi-element analysis of soils by ICP-AES with a CCD detection system

Three procedures, matrix matching, plasma optimisation and single-point standard-addition, have been evaluated to ascertain the best procedure for simultaneous multi-element analysis of industrial soils by ICP-AES with CCD detection. A standard reference material, CRM143 from the Bureau Communautaire de Réference (BCR), has been analysed for Cd, Cr, Cu, Mn, Ni and Pb using the three different matrix interference correction procedures. All three procedures give comparable results which are in good agreement with the BCR values, except for Cr. The single-point standard addition procedure was chosen, on the basis of economy and ease of implementation, to correct for matrix interferences in the determination of Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Sn and V in soil samples collected from an industrial site in England. Concentrations of some of the elements were found to vary greatly with sampling depth. For example, the concentration of Mn, determined using the atomic line at 279.920 nm, increased from 426 ± 3 g/g at a depth of 18–28 cm to 5996 ± 144 g/g at 60–85 cm.     

二维弥散介质温度场的快速重建

提出了一种利用电荷耦合器件摄像机获取的辐射信息进行二维弥散介质温度场快速重建的新模型. 与现有的温度场重建模型相比,该模型是以逆向Monte Carlo方法为基础,重建速度更快、效率更高,能更好地描述散射介质. 采用了一个精确的二维温度场作为重建对象,结果表明,即使在存在测量误差的情况下,利用此模型重建出的温度场仍能重现原有精确温度场的特征. 关键词： 温度场重建 逆向Monte Carlo 电荷耦合器件摄像机 反问题     

高效毛细管电泳－电荷耦合器件检测器联用技术研究Ⅰ．多波长荧光检测装置

报道了用电荷耦合检测器等设备组成的高效毛细管电泳多波长荧光检测装置。以荧光素和罗丹明Ｂ对其性能进行了评价,得到了具有光谱和时间分辨的三维电泳图,与被测物标准荧光光谱对照,可以直接鉴定被分离的化合物。     

Determination of volumetric shrinkage of thermally cured thermosets using video-imaging

Video-imaging is one method of analyzing the shrinkage of resins. For the measurement, a drop of resin is placed near an illumination source and its contour is imaged from the front with a camera. This paper presents a further development, detailed investigation and verification of this technique to analyze the chemical shrinkage of thermally cured epoxy resins during cure. A new cylindrical sample holder was developed which enables the automated detection of the baseline, as well as defining the scale within the pictures. In a test series, the resin's volume was varied, as well as its contour. The findings confirm that the measured volume shrinkage is independent of the drop shape.Finally, the obtained shrinkage results were verified and evaluated in comparison with values measured by a mercury dilatometer and a rheometer. The shrinkage results of the investigated new method are in good accordance with the more established methods.     

毛细管电泳光学检测器的进展

对毛细管电泳的光学检测器作了简要评述。根据所采用的检测原理。光源检测器可分为紫外检测器，激光诱导荧光检测器、化学肆光检测器、荷耦合器件检测器、折射指数检测器等许多种类，具有简单方便、使用广泛，信息量较大等特点，是一类有良好诉检测器。     

高效毛细管电泳-电荷耦合器件检测器联用技术研究Ⅳ.Monte Carlo模拟

根据毛细管电泳分离受不确定因素影响较多的特点，应用MonteCarlo模拟方法，探讨了电荷耦合器件检测器操作参数，进样、电压、温度等误差因素对检测信号强度、测定准确度和精密度的影响，比较了峰高和峰体积定量计算方法的相对优劣，对进一步开发和应用电荷耦合器件检测毛细管电泳技术有一定意义。     

实验研究大气压多脉冲辉光放电的模式和机理

采用稍不平行电极进行大气压He气介质阻挡多脉冲辉光放电实验,通过增强电子耦合器件相机短时曝光照片,研究大气压多脉冲辉光放电在不同时刻的放电模式.通过气隙放电电流、表面电荷计算,理论分析了表面电荷、空间电荷、外加电压与气隙电场强度的关系,研究大气压辉光放电形成多脉冲的机理.实验结果表明,放电首先在间隙稍窄的电极左端开始;在第一个脉冲电流峰值,电极右端也开始放电;第一个电流脉冲经历了Townsend放电到辉光放电的过程;电流脉冲之间的时间内,间隙一直维持着微弱的辉光放电;随后的每个电流脉冲均是辉光放电.理论分析表明,大气压辉光放电的多个电流脉冲是表面电荷、空间电荷与外加电压共同演化的结果;除放电伊始出现Townsend放电外,同一半周期内的放电电流脉冲中不会再出现Townsend放电.