硅基电泳芯片非接触电导检测器

研制了一种集成于硅基电泳芯片分离沟道末端侧壁的新型二电极非接触电导检测器.讨论了影响电导检测响应灵敏度的相关因素;采用MEMS分析软件及等效电路模拟仿真,确定了检测器的相关参数,电极长度为550μm,宽度为15μm,间距为80μm,绝缘层厚度为1μm,电导检测工作频率为300 kHz.在加工技术中,选用SOI(sili-con on insulator)基片制作十字形微沟道及集成电导检测电极,采用深刻蚀和隔离技术使检测电极被完全隔离成孤岛,利用硼掺杂技术在分离沟道末端侧壁形成立体电极,获得了集成非接触电导检测电极的硅基电泳芯片.在外加Vpp为10 V、工作频率为300 kHz的正弦波激励下,进行了Na+无机阳离子浓度梯度实验以及Na+和Li+混合无机阳离子的电泳分离检测.结果表明,Na+浓度在1×10-9～1×10-4 mol/L范围内,电导响应信号随着离子浓度的增加而增大,检出限达到1×10-9 mol/L;Na+和Li+混合无机阳离子的分离度达到2.0,实现基线分离.     

W/WO3 pH电极的制备以及表面膜微观分析研究

利用离子交换法制备了WO3的Sol溶液,并应用于H+选择性电极的敏感膜.电极有良好的H+响应,响应pH值范围为2～11,响应灵敏度约为52mV/pH.本文利用TG、DSC、IR、SEM、AFM、XRD等分析手段对WO3膜的组成与形态进行了表征,WO3形貌为龟裂泥土状,膜的组成为WO3、WO3·H2O或WO3·0.33H2O,随着热处理温度的提高,结晶水减少.EIS图谱表明电极的H+响应动力学过程为H+扩散过程控制,H+扩散系数为10-10cm2·S数量级.     

NASICON固体电解质SO2传感器的特性研究

采用溶胶-凝胶法合成NASICON固体电解质材料,并以其为基体材料制作管式SO2传感器,敏感电极采用Na2SO3-30?SO4或者Na2SO4-30?SO4(摩尔比)复合硫酸盐.SO2浓度在(10～100)×10-6体积分数范围内,两种器件的灵敏度分别为81.1和60.6mV/decade.敏感电极为Na2SO3-30?SO4的元件响应和恢复时间分别为28.2 s和57.7 s;敏感电极为Na2SO4-30?SO4的元件响应和恢复时间分别为39.8 s和67.4 s.     

机械可控纳米劈裂法实现单分子电导值的测量

为了获得电子在单分子结中传输的特性,研制了具有高稳定性的机械可控纳米劈裂装置芯片.利用此芯片及相应机械装置,获得了能在皮米级精度上操纵间距的纳米电极对;并实现了稳定的单个金属离子所桥接的分子结(电极-分子-金属离子-分子-电极).在保持配合物不变的前提下,置换不同金属离子,测量了其所桥接的单分子结的电导值,发现Ca2+络合物的电导值>>Zn2+络合物的电导值>Ni2+络合物的电导值.结合密度泛函理论的计算,验证了所得实验装置的可靠性及实验结果的正确性.     

毛细管电泳非接触电导检测器的研制

非接触电导检测法已经成为毛细管电泳芯片中一种通用的物质分离检测方法．本文提出了一种微型化的电容耦合非接触电导分析系统,采用新颖的三明治电极结构减小了电极之间的寄生电容．这种电极结构能够有效地减小电极的长度,克服了非接触电导检测中电极易于折断的缺点．当采用电极宽度1mm、电极间距1mm、MES／His缓冲溶液浓度为20mmol／L和激励电压20Vpp、90kHz的条件时,检测器具有最好的分离效果．在最佳的分离效果,实现了1mmol／L的K^＋和Mg^2＋混合无机阳离子的分离检测．     

基于层层自组装纳米碳管薄膜的应变传感器

以层层自组装单壁碳纳米管网状薄膜为敏感材料,在柔性基底上制作了应变传感器,并对薄膜和器件性能进行了测试。测试结果表明:薄膜组装均匀,电导性良好,电阻随组装层数增加呈指数态下降;器件对应变呈现较好的敏感特性、线性响应和可恢复性,灵敏度为4.25;通过添加防护层屏蔽外界湿度及光照影响,传感器稳定性显著提高。该传感器可用于弯曲表面的应力应变检测。     

Na+掺杂V2O5电极材料的制备及其储锌性能

针对V2O5电子传输慢、离子 扩散受阻以及循环性能不稳定等问题,通过一步水热法制备Na0.4V2O5纳米粉体材料,并作为锌离子电池正极材料。结果表明,Na0.4V2O5电极的倍率性能和循环稳定性均优于V2O5电极。Na+掺杂通过改变V2O5的层状结构,改善V2O5的电子传输和离子扩散,从而提高电极电导特性和结构稳定性。Na0.4V2O5电极是倍率性能和循环稳定性优良的电极材料。     

气相色谱仪检测器性能指标的讨论

灵敏度和检测限是气相色谱仪检测器的主要性能指标,正确理解灵敏度和检测限之间的关系,对气相色谱仪的选购和气相色谱仪的计量检定及准确测量具有重要的意义.本文主要讨论设定合理的检测器参数指标以及如何进行检定和校准.     

介质阻挡放电等离子体检测器在分析气体中微量组分的应用

使用介质阻挡放电等离子体检测器(BID)对几种气体中特殊组分进行了分析方法研究。使用不同类型的色谱柱,在实验条件下,实现目标气体组分的全部分离检测。砷烷、二氧化硫、氨气、氯气、甲醛、水分可以使用TCD检测器进行分析,灵敏度却很低,但是在BID检测器上,这几种物质却表现出很高的响应;含氧有机物和含卤素有机物通常在FID检测器上进行分析,但是在含量很低的时候响应却不理想,BID检测器对于含卤素有机物和含氧有机物有着很高的响应峰面积。含硫化合物一般采用气相色谱FPD和SCD来检测,但是FPD和SCD使用条件限制多,维护繁琐,BID检测器对含硫化合物有着不错的灵敏度和较高的线性范围,通过对以上物质进行分析方法研究,实验结果完全可以满足微量、痕量定量分析的要求。     

新型PVC膜锌离子选择性电极研究

研制以3,5-二溴水杨醛二缩邻苯二胺为中性载体的新型聚氯乙烯(PVC)膜锌离子选择性电极。该电极对Zn2+具有良好的选择性,呈现出近能斯特电位响应,响应线性范围为1.0×10-5¹.0×10-1mol/L,检出限8.0×10-6mol/L,斜率为36.8mV/dec。电极的响应时间为55s,在连续使用一个月后其电位响应性能未见下降。电极的响应机理通过交流阻抗技术进行初步研究,可应用于工业废水、饲料、药品等样品中锌含量的检测。     

Reduction of the impedance of a contactless conductivity detector for microchip capillary electrophoresis: compensation of the electrode impedance by addition of a series inductance from a piezoelectric quartz crystal

A low-impedance capacitively coupled contactless conductivity detector (LIC (4)D) for microchip capillary electrophoresis was reported. The LIC (4)D was the series combination of a piezoelectric quartz crystal (PQC) resonator with a capacitively coupled contactless conductivity detector (C (4)D) outside on the microchip lid. The electrode impedance in the LIC (4)D was reduced because the capacitive impedance from the wall capacitance was compensated by the inductive impedance from the PQC. The operation frequency of the LIC (4)D was set at the resonant frequency of the series combination of a PQC with a C (4)D, wherein a minimum in the total impedance was obtained. It was shown that the sensitivity of LIC (4)D was much higher than that of C (4)D itself, especially in the microchip with a thick lid. Under the experimental conditions, the signal-to-noise ratios of the LIC (4)D were improved by approximately 20-50 times over those of the C (4)D. Reproducible separations of a mixture of inorganic cations (K (+), Na (+), Li (+)) were demonstrated. After a digital filter treatment by the fast Fourier transform algorithm, the detection limits were 0.38, 0.49, and 1.6 microM for K (+) in the LI C (4)D with the microchip lid thickness of 0.20, 0.40, and 1.0 mm, respectively.     

二氯喹啉酸的高效液相色谱法测定

建立了二氯喹啉酸的高效液相色谱(HPLC)快速检测方法。二氯喹啉酸俗称快杀稗,属激素型喹啉羧酸类除草剂。用高效液相色谱法测定除草剂中二氯喹啉酸的含量,通过改变高效液相色谱的检测波长、流动相的配比,确定测定二氯喹啉酸的最佳测定条件,以甲醇+水+冰乙酸(85:15:0.1)为流动相,采用C18柱(250 mm×4.6 mm×5μm)分离,在uV238 nm检测,外标法定量。以SPD-10AVP型检测器对试样中的二氯喹啉酸原药进行分离和定量分析。结果表明,二氯喹啉酸的线性相关系数为R=0.9998;标准偏差为0.29;变异系数为0.36;回收率82%～94%。     

氧弹燃烧-离子色谱法测定螺旋藻中碘

建立氧弹燃烧-离子色谱法测定螺旋藻中碘含量方法。方法选用Metrosep A Supp 4色谱柱,1.8mmol/L Na2CO3+1.7mmol/L NaHCO3淋洗液,流速1mL/min,电导检测器。样品氧弹燃烧法处理,然后用(0.714g NaHCO3+0.954g Na2CO3)/L吸收液吸收,定容后过滤待测。用于螺旋藻样品分析,回收率为102%。本法快速、简便、灵敏。样品测定结果令人满意。     

Characteristics of highly sensitive terahertz wave detector based on lithium niobate

The characteristics of a highly sensitive terahertz wave detector based on lithium niobate have been investigated using a steady-state theory. The contributions of the low-frequency modes to the dielectric constant of lithium niobate are considered. The intrinsic factors of the LN detector limit its high frequency response to about 4?THz. Temperature dependence of the detector from room temperature to 250°C was also studied. The main factors associated with the temperature variations of the sensitivity of the detector are thermal expansion, the nonlinear coefficient and the refractive index of the crystal. The nonlinear coefficient dominates the temperature dependence of the sensitivity of the detector, while the impact of the refractive indices of the near-infrared lights on the temperature variation of the sensitivity of the detector is negligible. This study provides a useful guide and a theoretical basis for the further improvement of the detection systems.     

成像检测在DNA毛细管电泳中的应用

本文研究了成像检测方式以及阵列检测器在DNA毛细管电泳的荧光检测中的应用,目的在于减小检测过程引起的样品区带增宽,提高DNA毛细管电泳的分辨率和分离速度。依据分离度理论以及模拟计算结果,归纳了检测宽度的影响规律,指出减小检测宽度对于高效分离,特别是高速微流控系统电泳分离的重要性。实验测量并比较了成像检测与传统光强检测的结果。提出阵列检测器的信号增强方法,并进行了模拟验证。研究表明,成像检测可显著减小毛细管电泳的检测宽度,提高分离效率和分离速度。     

基于超薄钽酸锂晶片及炭黑红外吸收层的热释电探测器

基于钽酸锂(LiTaO3)的热释电探测器具有灵敏度高、热释电系数大、响应范围宽等优点而被广泛应用于非分光红外气体检测.在LiTaO3热释电探测器制备过程中,采用预置沟槽方法制备出约20μm厚的超薄LiTaO3晶片,该方法既能控制晶片厚度又能实现自动解片,简化了探测器制备工艺;采用电喷雾方法制备出炭黑红外吸收层,该方法工艺简便,制备的吸收层分布均匀,结构疏松.电喷雾时间为20 min时制备的吸收层在常用气体吸收波段(2.5~10μm)的红外吸收率达98%以上,使探测器信号幅值提高了约2.6倍.热释电探测器性能测试结果表明:单元结构探测器的黑体探测率可达1.78×108cm·Hz1/2/W;二元补偿结构探测器信噪比为单元器件的2倍;将二元补偿结构探测器应用于非分光红外气体测试系统,进行了SO2气体检测,等噪声检测下限约为1×10-6.     

Integrated electrophoresis chips/amperometric detection with sputtered gold working electrodes

An on-chip electrochemical detector for micromachined capillary electrophoresis (CE) systems, based on sputtering a gold working electrode directly onto the capillary outlet, is described. The new on-chip detector preparation requires no microfabrication or alignment procedures nor a decoupling mechanism. The attractive performance of the integrated electrophoresis chips/amperometric detection was demonstrated for the anodic detection of neurotransmitters. The response for dopamine was linear from 20 to 200 μM, with a LOD of 1.0 μM and a sensitivity of 52 pA/μM. Such intimate coupling of capillary electrophoresis chips and electrochemical detection facilitates the realization of complete integrated microanalytical devices.     

Miniaturisation of a capillary electrophoresis microchip for the sensing of endocrine disruptors

Although capillary electrophoresis amperometric detector (CE-AD) involving double-T microchannel configuration is a powerful analytical tool in terms of sensitivity and selectivity, its long microchannel configuration hinders further miniaturisation. Therefore a twisted CE microchannel configuration was used in the present study to fabricate CE-AD devices for detection of endocrine disruptors. The analyte separation time varied slightly for the twisted microchannel structure, whereas the detector sensitivities were similar for the two configurations. The conventional indium tin oxide amperometric detector in the device with twisted microchannel configuration was later modified with Prussian blue to enhance the sensitivity of detection.     

高效液相色谱法鉴定嫌疑药丸中西地那非

本文研究了药丸中西地那非的高效液相色谱法鉴定。色谱柱为XDB-C18,5μm,4.6×150mm,二极管阵列检测器检测230nm(带宽4nm),流动相为35%乙睛+65%0.025mmol/L KH2PO4(含0.1‰v/v乙二胺)(pH5.57),流速1mL/min。样品用水溶解,外标法定量。检出限(LOD,S/N=3)为3μg/mL,定量限(LOQ,S/N=5)为4μg/mL。1000μg/mL、600μg/mL和200μg/mL的回收率分别为98.8%、101.3%和99.9%。6次测定600μg/mL和200μg/mL的相对标准偏差(RSD%)分别为2.4%和2.6%。在20～1000μg/mL范围内线型回归方程为Y=16.692X+50.17(Y为相应信号,mAU;X为浓度,μg/mL),回归系数R2为0.9998。该方法样品处理简单,定量准确度高,干扰小,可用于药丸中西地那非的法庭科学鉴定。