基于提取两级催化发光信号以鉴别醚蒸气的传感器

本研究基于两个催化敏感材料, 建立了一种鉴别不同醚蒸气的新方法. 分别让四种醚蒸气经过纳米MgO(或ZrO₂)表面进行催化发光(Cataluminescence, CTL)反应(称其为一级反应), 产生CTL响应信号I₁. 再让反应后的尾气作为新的反应物经过纳米MgO(或ZrO₂)表面进行CTL反应(称其为二级反应), 产生新的CTL响应信号I₂. 实验发现: 在波长425 nm、流速220 mL/min、温度240 ℃的检测条件下, 四种醚蒸气分别依次经过MgO-MgO和ZrO₂-MgO材料时产生的一、二级CTL信号比值I₁/I₂是常数, 不随浓度变化而变化, 可以鉴别和区分不同的醚蒸气. 通过改变分析气体流经ZrO₂-MgO的方向, 可以得到每种醚蒸气的四组CTL强度比值I₁/I₂, 据此可获得多维信息来增强传感器鉴别醚蒸气的能力. 该传感器具有稳定性好、造价低和鉴别能力强的优点.     

提取多维催化发光信号鉴别有害气体的传感器

基于2种催化敏感材料, 设计了通过提取多维发光信号鉴别有害气体的催化发光(CTL)传感器. 在最佳检测条件下, 18种有害气体依次经过纳米Al₂O₃(或MgO)表面进行CTL反应, 产生的CTL 响应信号组成其特征图谱. 通过主成分分析法(PCA)鉴别了各种气体. 采用线性判别分析(LDA)对浓度分别为100, 300及500 mL/m³的18种气体的识别正确率均为100%. 该传感器可以同时测量气体的浓度, 检出限均低于我国工作场所有害因素职业接触限值(GBZ2.1-2007), 空气中几种常见的污染物共存不影响这些有害气体的检测. 该传感器具有传感元件少、 稳定性好、 操作方便、 信息丰富和识别能力强等优点, 可用于发展微型实用的传感器.     

基于水滑石-金纳米粒子的阻抗型核酸适配体传感器的研究

在玻碳电极表面用电化学沉积法一步合成钴铝水滑石-金纳米粒子(CoAl LDH-GNPs)复合纳米材料,以复合纳米材料作为核酸适配体(Apt)的固定化基质,建立了一种高灵敏的阻抗型适配体传感器.采用扫描电镜(SEM)和能量色散谱仪(EDS)对CoAl LDH-GNPs复合纳米材料进行了表征,对电极的组装过程采用循环伏安法和电化学阻抗进行表征,对传感器的性能采用电化学阻抗进行研究.复合纳米材料CoAl LDH-GNPs构筑的传感器对凝血酶(THR)具有良好的信号响应,线性相关系数R=0.995,检出限为0.3 ng/L(S/N=3),检测范围为1.0 ng/L～ 100 μg/L.     

光纤分导微梁阵列生化传感装置研制及检测应用

研制了一套基于光杠杆原理的微悬臂梁阵列传感器平台,并通过使用设计制作的微悬臂梁阵列芯片展示其在生物化学方面的检测应用.传感器平台使用光导纤维束分别与激光器耦合作为悬臂梁阵列的扫描光源,具有良好的检测稳定性,检测信号噪声水平约为2 nm;设计制作的微悬臂梁阵列芯片具有良好的平直度,温度响应均匀一致,各梁温度改变响应灵敏度偏差不超过5.0％.将整套传感系统被用于检测水溶液中的Hg2+,检测浓度范围为1 ～ 200 ng/mL;同一浓度下微悬臂梁阵列检测结果曲线一致性良好,平均偏差小于15％.在研制仪器平台上,分别实现了自制和国外商品化芯片对1.0和0.2 ng/mL样品的检测,结果表明,制作的微悬臂梁阵列芯片的检测灵敏度相对较低,需进一步改进悬臂梁阵列制作工艺.     

卟啉纳米材料制备及在可视化传感器中的应用

在水/油体系中,利用表面活性剂辅助自组装制备出5,10,15,20-四苯基卟啉锌(ZnTPP)和5,10,15,20-四苯基卟啉钴(CoTPP)纳米材料,改变陈化时间制备多种形貌卟啉纳米材料,如纳米球、纳米棒和纳米片等。利用紫外-可见光谱和荧光光谱分析两种卟啉纳米材料的光学性质,ZnTPP纳米材料的荧光强度是其单体的4.5倍,具有良好光敏性。基于两种卟啉纳米材料构建可视化阵列芯片对挥发性气体己醛检测,卟啉纳米的响应度是它们单体的2倍。     

基于金纳米材料的可视化生物传感器的研究进展

可视化检测方法是一种以光学响应信号为基础,通过裸眼比较反应液中颜色的深浅或种类的变化,实现对目标物的肉眼识别检测,具有检测结果可视化、操作简单快捷、检测成本低和响应速度快等优点。在各种纳米材料中,金纳米材料由于具有独特的光学性质,被广泛用于可视化传感器的构建。当纳米粒子之间的距离或形貌改变时,其局域表面等离子共振吸收峰会产生相应的变化,引起溶液颜色的改变。本文综述了近几年基于金纳米材料的可视化传感器在分析检测中的研究进展,分析了该技术在实际应用中面临的主要问题,并对未来的发展前景进行了展望。     

基于Dy_2(MoO_4)_3-AuNPs复合纳米材料的葡萄糖生物传感器

采用水热法合成了纳米材料钼酸镝[Dy_2(MoO_4)_3],并制备了Dy_2(MoO_4)_3-AuNPs复合材料,利用该复合材料固定葡萄糖氧化酶(GOD)构建了葡萄糖生物传感器.通过透射电子显微镜(TEM)、紫外-可见光谱(UV-Vis)和能谱分析(EDS)等手段对所制备的材料进行了表征,并利用电化学阻抗谱(EIS)和循环伏安(CV)曲线研究了该传感器的电化学性能.结果表明,Dy_2(MoO_4)_3-AuNPs复合材料具有较好的生物相容性,能增强固定化的GOD的生物活性,并促进GOD在电极表面的电子传递速率;该传感器在葡萄糖浓度为0.01~1.0 mmol/L范围内葡萄糖浓度与响应电流呈较好的线性关系,最低检出限为3.33μmol/L(S/N=3),该生物传感器还具有较好的稳定性和重现性.     

电化学发光和电化学生物传感器的研究

本研究小组近年来在电化学发光DNA和适体传感器研究和无标记以及阵列电化学DNA和适体传感器方面进行了一些工作,重点介绍如何提高生物传感器灵敏度进行传感界面设计的一些思路.利用纳米粒子提高灵敏度和再现性的途径主要有三种,一是用纳米材料修饰电极上,提高待测物或探针在电极表面的固定量;二是用纳米材料作为信号分子的载体或信号粒子, 以提高检测信号的强度~([1]);三是纳米材料直接作为信号物质~([2]).     

CuS/TiO2纳米管异质结阵列的制备及光电性能

利用水热反应制备了CuS/TiO2纳米管异质结阵列,采用场发射扫描电子显微镜(FESEM)、透射电子显微镜(TEM)和X射线衍射谱(XRD)等手段表征了异质结阵列的表面形貌和晶体结构.电流-电压曲线结果表明,CuS/TiO2纳米管异质结阵列具有明显的整流效应.根据表面光电压谱和相位谱,在376～600 nm之间,CuS/TiO2纳米管异质结阵列表现为p型半导体特征,电子在表面聚集;在300～376 nm之间表现为n型半导体特征,空穴在表面聚集;在376 nm处异质结阵列的表面光伏响应为零.CuS/TiO2和CuS/ITO之间界面电场的不同导致异质结在不同波长范围内表面电荷聚集的差异.光电化学性能测试发现,以CuS/TiO2纳米管异质结阵列为光阳极组成的光化学太阳电池,在大气质量AM 1.5G,100 mW/cm2标准光强作用下具有0.4%的光电转换能力.     

基于石墨烯基复合物和聚天青Ⅰ的HRP传感器检测有机过氧化物的研究

利用电化学还原氧化石墨烯(GO)的方法将石墨烯(rGO)固定在电极表面上,然后电沉积氢氧化铜和氢氧化镍复合物,构成石墨烯/金属氢氧化物复合纳米材料修饰的玻碳电极(GCE),并通过电聚合天青Ⅰ将辣根过氧化酶(HRP)固定在GCE/rGO/Cu(OH)_2-Ni(OH)_2表面,制得GCE/rGO/Cu(OH)_2-Ni(OH)_2/HRP-PA。对石墨烯/金属氢氧化物复合纳米材料进行了SEM和能谱表征。通过电化学阻抗法和循环伏安法对传感器的制备过程和电化学性能进行了研究,并进一步分别对过氧化氢叔丁基(BHP)及过氧化氢异丙苯(CHP)进行了分析测定。该传感器对BHP和CHP具有良好的检测效果,在2.0×10~(-5)~9.2×10~(-4)mol/L范围内响应电流与BHP浓度呈良好的线性关系,检出限为9.9×10~(-6)mol/L;在3.0×10~(-6)~1.0×10~(-4)mol/L范围内响应电流与CHP浓度呈良好的线性关系,检出限为6.9×10~(-7)mol/L。     

A comparison of two algorithms for warping of analytical signals

The alignment of analytical signals is an important preprocessing step when further analysis (e.g. PCA) requires the same lengths of all of them. Two techniques for alignment of profiles, namely dynamic time warping (DTW) and correlation optimized warping (COW) were tested and compared. The attention was focused on chromatographic and spectroscopic profiles. Simulated and two sets of real data were studied in this study.     

Electrical characteristics of a millisecond pulsed glow discharge

A μs and ms pulsed argon glow discharge was investigated with respect to the breakdown condition (Paschen curve). Moreover, current–voltage profiles were acquired for different discharge frequencies, pulse durations, cathode–anode spacing and discharge pressures. The breakdown voltage was dependent on the cathode material (Cu, steel, Ti and Al). No severe change in the breakdown voltage was observed for a 1 ms pulse at different frequencies. However, the theoretical breakdown curve, calculated based on the Paschen equation did not fit the experimental data. The current plots for different cathode–anode spacing showed a maximum at intermediate distance (8–10 mm). These data were consistent with mass spectrometric data acquired using the same instrument in a GC-GD-TOFMS chemical speciation study.     

纳米材料在蛋白质直接电化学研究中的应用

对1991~2008年间各种纳米材料,包括纳米金属粒子、纳米无机材料、纳米碳材料等在蛋白质直接电化学中的应用进行了综述,引用文献58篇。     

纳米材料在电化学生物传感器中的应用及纳米仿生界面的构建

对1995～2011年间各种纳米材料,包括金属纳米粒子、量子点纳米材料、碳纳米材料、复合纳米材料等在电化学生物传感器中的应用及纳米仿生界面的构建进行了综述。     

抗菌素痢菌净与牛血清白蛋白相互作用的光谱研究

用荧光光谱和紫外吸收光谱法研究了抗菌素痢菌净(MEQ)与牛血清白蛋白(BSA)的相互作用。讨论了荧光猝灭机理,结果表明是动态猝灭过程;计算了不同温度下的猝灭常数和热力学参数。MEQ与BSA的相互作用为一个由熵驱动的自发过程,疏水作用力也起重要作用。由FRET能量转移理论计算得出了MEQ与BSA结合位置的距离r=4.5 nm。应用同步荧光和三维荧光研究了BSA在MEQ存在或不存在时的构象变化,结果表明：MEQ对BSA构象的影响不大。     

Characterization of major degradation products of an adenosine A2A receptor antagonist under stressed conditions by LC‐MS and FT tandem MS analysis

Parkinson's disease (PD) is a very serious neurological disorder, and current methods of treatment fail to achieve long‐term control. SCH 420814 is a potent, selective and orally active adenosine A_2A receptor antagonist discovered by Schering‐Plough. Stability testing provides evidence of the quality of a bulk drug when exposed to the influence of environmental factors. Understanding the drug degradation profiles is critical to the safety and potency assessment of the drug candidate for clinical trials. As a result, identification of degradation products has taken an important role in drug development process. In this study, a rapid and sensitive method was developed for the structural determination of the degradation products of SCH 420814 formed under different forced conditions. The study utilizes a combination of liquid chromatography–tandem‐mass spectrometry (LC‐MS/MS) and Fourier Transform (FT) MS techniques to obtain complementary information for structure elucidation of the unknowns. This combination approach has significant impact on degradation product identification. A total of ten degradation products of SCH 420814 were characterized using the developed method. Copyright © 2009 John Wiley & Sons, Ltd.     

Role of PTFE paste fibrillation on Poisson's ratio

Polytetrafluoroethylene (PTFE) flat profiles were extruded using slit dies, which promoted orientation of fibrils in two directions (2-D). Uniaxial tensile experiments were performed on the collected extrudates using the Sentmanat Extensional Rheometer (SER) at different temperatures and Hencky strain rates to determine the mechanical properties of the material. A nonlinear viscoelastic model developed by Matsuoka was found to describe well the transient tensile results using Poisson's ratio as a parameter. Polarized Raman Spectroscopy was also used to gain additional information on the degree of fibril orientation at different locations both along and across the width and length of the extrudates. Results of the Raman spectra were found to be in agreement with the fibril structure/morphology obtained from SEM micrographs. The compressibility of the extrudates upon stretching was studied by measuring the relative density. The results are modeled using a simple equation including the elastic strain recovery coefficient (κ) and Poisson's ratio.     

一种新的氨基酸描述符及其在肽QSAR中的应用

从20种天然氨基酸的41个randic molecular profiles非零描述符、44个eigenvalue based indices非零描述符和47个walk and path counts非零描述符分别进行主成分分析,得出一种新的氨基酸描述符-SVREW。将其应用于血管紧张素转化酶(ACE)抑制二肽和ACE抑制三肽、苦味二肽和苦味四肽、后叶催产素类似物、HLA-A*0201限制性CTL表位肽的结构表征,应用多元线性回归(MLR)建立定量构效关系模型,同时采用内部与外部双重验证的方法验证模型的稳定性。所建ACE抑制二肽、ACE抑制三肽、苦味二肽、苦味四肽、后叶催产素类似物、HLA-A*0201限制性CTL表位肽的模型复相关系数(R2cum)分别为0.994,0.797,0.948,0.878,0.686,0.720;留一法交互校验复相关系数(R2cv)分别为0.955,0.859,0.879,0.958,0.796,0.843;外部样本校验相关系数(Q2ext)分别为0.990,0.954,0.890,0.950,0.748,0.773。经研究表明SVREW描述符用于肽分子结构表征所建模型的稳定性与预测能力均较好,有望成为多肽定量构效关系研究中一种有效的结构表征方法,可对新药物的发现和研究提供指导。     

Mutation scanning-coupled analysis of haplotypic variability in mitochondrial DNA regions reveals low gene flow between human and porcine Ascaris in endemic regions of China

Haplotypic variation within and among the Ascaris populations representing six provinces in China was investigated. Mitochondrial DNA regions in the cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase subunit 1 (nad1) genes were amplified by PCR from total genomic DNA samples (n > 720) from Ascaris individuals from humans and pigs, and subjected to mutation scanning and subsequent selective sequencing. For the cox1, ten different electrophoretic profiles were recorded for human Ascaris, and the same number for pig Ascaris, one of them being common to both host species. For the nad1, 11 different profiles were detected for human Ascaris, and 15 for pig Ascaris. Having defined all haplotypes (20 for pcox1 and 26 for pnad1) by sequencing, their frequencies were estimated in each of the two host species and each of the six provinces. For each mitochondrial region, the frequency of the different haplotypes varied considerably, depending on host species and geographical origin. Analysis of the sequence data (representing all haplotypes for each mitochondrial locus) by F-statistics indicated restricted gene flow between human Ascaris and pig Ascaris, and supported the conclusions from previous molecular epidemiological investigations that pigs are not a significant source of Ascaris infection in humans in endemic regions.     

Cu2+掺杂的NdCoO3纳米材料及其气敏性能

利用柠檬酸溶胶凝胶法成功合成了Cu2+掺杂的NdCoO3纳米材料,经粉末X射线衍射(XRD)和扫描电镜(SEM)表征后发现,所得掺杂NdCoO3纳米材料为纯相的立方钙钛矿结构,其尺寸约为80～200纳米。将改性前后的NdCoO3纳米材料分别制作成气敏元件并对其电性能和气敏性能进行了对比研究。结果发现,Cu2+的掺杂可以明显降低NdCoO3气敏元件的电阻、提高对H2S的灵敏度。表明这种改性的NdCoO3纳米材料将来有可能成为一种H2S敏感材料,也为NdCoO3纳米材料的应用提供了一条新颖的途径。