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顾春华 《分析测试技术与仪器》2009,15(3):191-193
采用干灰化法、湿氧化A法和B法分别对油画颜料进行消解后用原子吸收火焰法测定其中的铅含量.通过分析比较3种消解方法测定的结果,发现采用湿氧化法优于干灰化法,湿氧化A法优于B法.采用湿氧化A法对油画颜料进行加标处理后,加标回收率在90%-105%范围,表明采用该方法测定油画颜料中的铅含量是可信的. 相似文献
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B因子是一种不耐热的球蛋白,它参与机体的防御,在炎症的过程、细胞和组织损伤中均起重要作用。B因子的检测方法常用的有单扩散法、火箭电泳法和溶血法,前者灵敏度不高,重复性差;后两者操作较复合^[1,2].因此,寻找一种简单、快速、灵敏且可精确定量的检测方法在临床医学上很重要的价值。压电免疫传感器具有仪器装置简单、灵敏度高、能快速检测、无需标记、可精确定量等优点,已被广泛应用^[3]。聚乙烯亚胺粘附和戊二醛交联法常用于石英晶体电极上抗体的固定^[4]。本文采用这一方法固定B因子抗体,研制了一种新型的传感器,用于B因子的检测,并选用4种解吸剂研究了电极的可重复性。 相似文献
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采用吸收光谱法研究了十二烷基硫酸钠(SDS)诱导Rhodobacter azotoformans外周捕光复合体LH2 细菌叶绿素(bacteriochlorophylls, BChls)的解离行为和规律. 结果表明: 室温下, 在10 mmol•L-1 Tris-HCl (pH 8.0)缓冲液中, 低浓度SDS只诱导LH2中B800 细菌叶绿素解离生成游离BChls, 而B850不受影响; 当浓度达到0.08% (w/V) 时, 能特异性地诱导B800缺失, 其缺失过程和游离BChls的生成过程均符合单指数模型, 且二者的速率常数近似相等. 高浓度SDS能同时诱导B800和B850解离生成游离BChls, 其中B800可发生缺失, 而B850则不完全解离, 解离过程均符合单指数模型; B800对SDS更敏感, 其解离速率常数约是B850的4倍, 游离BChls生成速率常数明显低于B800解离速率常数, 而与B850解离速率常数相接近. 相似文献
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在丙型肝炎病毒(HCV)的基因复制和蛋白质成熟的过程中, 非结构蛋白5B(NS5B)作为RNA依赖的RNA聚合酶起到了重要的作用. 抑制NS5B聚合酶可以阻止丙型肝炎病毒的RNA复制, 因此成为一种治疗丙型肝炎的有效方法. 通过计算机方法进行虚拟筛选和预测NS5B聚合酶抑制剂已经变得越来越重要. 本文主要采用机器学习方法(支持向量机(SVM)、k-最近相邻法(k-NN)和C4.5决策树(C4.5 DT))对已知的丙型肝炎病毒NS5B蛋白酶抑制剂与非抑制剂建立分类预测模型. 1248个结构多样性化合物(552个NS5B抑制剂与696个非NS5B抑制剂)被用于测试分类预测系统, 并用递归变量消除法选择与NS5B抑制剂相关的性质描述符以提高预测精度. 独立验证集的总预测精度为84.1%-85.0%, NS5B抑制剂的预测精度为81.4%-91.7%, 非NS5B抑制剂的预测精度为78.2%-87.2%. 其中支持向量机给出最好的NS5B抑制剂预测精度(91.7%); C4.5决策树给出最好的非NS5B抑制剂预测精度(87.2%); k-最近相邻法给出最好的总预测精度(85.0%). 研究表明机器学习方法可以有效预测未知数据集中潜在的NS5B抑制剂, 并有助于发现与其相关的分子描述符. 相似文献
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采用浸渍法制备了B掺杂的Cd0.5Zn0.5S光催化剂,考察了不同B掺杂量的Cd0.5Zn0.5S催化剂在可见光光照下的放氢活性和稳定性.实验结果表明,B掺杂可以显著提高催化剂的活性和稳定性.B的掺杂量对催化剂的活性有显著影响,最佳担载量为2%.在利用XRD、PL、XPS、UV-V is等手段对催化剂表征的基础上,结合光催化性能测定结果与催化剂表征结果,初步探讨了B掺杂对Cd0.5Zn0.5S光催化剂性能的影响机制.结果表明,B掺杂显著地增强了B/Cd0.5Zn0.5S催化剂的紫外-可见漫反射和荧光光谱强度.XPS结果表明,催化剂中的B物种不是以简单氧化物的形式存在,而可能是通过某种化学反应与Cd0.5Zn0.5S光催化剂作用,使催化剂的性能得以改善. 相似文献
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四硼酸钾水溶液结构 总被引:4,自引:0,他引:4
研究了298.15和323.15K广泛浓度范围内四硼酸钾溶液pH,并根据化学反应平衡常数和牛顿迭代法计算获得了溶液化学物种分布图.典型样品用拉曼光谱进行核实.研究表明,高浓溶液中存在主要化学物种是B4O5(OH)24-,次要化学物种是B3O3(OH)4-和B(OH)4-.用X射线散射法研究了298和323K高浓四硼酸钾溶液结构.用几何模型定量描述B4O5(OH)42-,B3O3(OH)-4和B(OH)-4离子内、离子间、分子间的相互作用,并用最小二乘法进行精修.模型计算和精修给出硼氧六元环内原子间距和配位数,并与晶体结构很好一致,表明高浓溶液中离子内有序程度较高.同时给出K+和硼酸根离子水合数和水合距离,以及接触离子对的结构信息,并进一步简单讨论温度和浓度变化对溶剂结构的影响. 相似文献
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蛋白A定向固定抗体的纤维蛋白压电免疫传感器的研究 总被引:17,自引:2,他引:17
将9MHz双面镀金石英晶体浸入蛋白A溶液中,在晶体电极表面形成一层均匀的蛋白A薄层,用于定向固定人体纤维蛋白抗体.在蛋白A层上形成一层有序致密的自组装抗体分子膜,研制成一种新型的用于人体纤维蛋白检测的压电免疫传感器.比较了3种固定抗体方法的效果,从传感器的灵敏度、稳定性、重现性等考虑,蛋白A吸附法优于聚乙烯亚胺及牛血清白蛋白固定抗体的方法.研究了蛋白A浓度、抗体效价以及抗原抗体反应时间等对传感器灵敏度的影响,考察了电极的选择性和再生能力.纤维蛋白在1×10-4~1×10-2g/L浓度范围内有良好响应. 相似文献
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A piezoelectric sensor responsive to vitamin B1 was fabricated based on the vitamin B1-tetraphenylborate ion pair. The general performance characteristics of the sensor are presented here. The proposed sensor showed a wide working pH range, a good sensitivity and selectivity. The response range is between 1.0×10-7-4.9×10-5 mol/L with a detection limit of 8×10-8 mol/L at pH 4.0. The selectivity should be attributed to the preferential adsorption of the component ion on the membrane/solution interface. The adsorption behavior of vitamin B1 on the crystal surface was investigated with a quartz crystal impedance(QCI) system. 相似文献
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压电免疫传感器用于C2型葡萄球菌肠毒素的测定 总被引:2,自引:0,他引:2
报道了用蛋白A-金电极法将抗体固化在3.58MHz和10HzAT切割的石英晶体上,制作的可重复使用的压电免疫传感器,测定C2型葡萄球菌肠毒素。最适PH值为7,并用不同的方法测试了晶体片上的抗体固化情况。 相似文献
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A piezoelectric immunosensor has been developed for the detection of complement C4. Anti-C4 antibody was immobilized onto the gold electrodes of a 9 MHz AT-cut piezoelectric crystal. The coated crystal with the physical adsorption method to immobilize antibody showed the better results than the polyethyleneimine adhesion, glutaraldehyde cross-linking method with respect to sensitivity and reproducibility. The antibody-bound crystal with the physical adsorption method was successfully used for the detection of human complement C4 in the concentration range of 0.1-10 μg/mL for 40 min incubation time. The immunosensor system had good selectivity, and other materials in human serum did not interfere the detection remarkably. The crystal could be regenerated nearly 15 times when the bound materials on the crystal surface were eluted by strong acid and strong alkali solutions and subsequently cleaned in a ultrasonic cleaner. 相似文献
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Zhixian Gao Jie Ren Baoan Ning Huizhong Zhu Yonghong He 《International journal of environmental analytical chemistry》2013,93(8):599-606
Because of their high sensitivity, piezoelectric sensor techniques are extremely useful for environmental or clinical analysis. We developed a piezoelectric crystal DNA biosensor for the detection of the hybridization reaction based on the self-assembled monolayer technology and biotin–avidin system. 3,3′-Dithiopropionic acid was applied to form a self-assembled monolayer (SAM) on the gold surface of the quartz crystal. Avidin was coated on the gold electrode conjugated with 1-ethyl-3-[3-(dimethylamino)propyl]-carbodiimide (EDC) and N-hydroxysuccinimide (NHS), and then biotinylated nucleotide acids were immobilized on the gold electrode surface through the specific interaction of biotin and avidin. Our results indicated that, using this immobilization method, the piezoelectric DNA sensor shows a higher sensitivity and specificity in detecting the hybridization reaction. The sensor can be used repeatedly by electrode regeneration. 相似文献
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A piezoelectric crystal immunosensor has been developed for the detection and determination of cortisol. Cortisol antibody was layered onto the gold electrodes of a 10 MHz piezoelectric crystal which was pre-coated with either protein A or gluteraldehyde. Crystals pre-coated with protein A showed the best results with respect to stability and sensitivity. The sensor was successfully used for the determination of cortisol in standard solutions from 36-3628 micrograms/L (part per billion). The advantages of the proposed sensor include simplicity, short analysis time, cost effectiveness and selectivity. The results demonstrate the feasibility of cortisol assay in clinical testing and in drug monitoring. 相似文献
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A novel piezoelectric immunosensor has been developed for the detection of human complement C1-inhibitor. Anti-C1-inhibitor antibody was immobilized onto the gold electrodes of a 9 MHz AT-cut piezoelectric crystal. Coating the crystal with polyethyleneimine adhesion, followed by a glutaraldehyde cross-linking method to immobilize antibody showed better results than the physical adsorption method with respect to sensitivity and reproducibility. Under the optimized experimental conditions, the sensor showed good response to the C1-inhibitor in the range from 2.0 x 10(-8) to 1.2 x 10(-6) g. Other proteins in human serum did not remarkably interfere with the detection. The crystals could be regenerated 5 times, when bound materials on the crystal surface were eluted by strong acid and strong alkali solution and subsequently cleaned in an ultrasonic cleaner. 相似文献
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《Analytical letters》2012,45(12):2149-2159
Abstract A piezoelectric crystal immunosensor has been developed for the detection and determination of cortisol. Cortisol antibody was layered onto the gold electrodes of a 10 MHz piezoelectric crystal which was precoated with either protein A or gluteraldehyde. Crystals pre-coated with protein A showed the best results with respect to stability and sensitivity. The sensor was successfully used for the determination of cortisol in standard solutions from 36–3628 μg/L (part per billion). The advantages of the proposed sensor include simplicity, short analysis time, cost effectiveness and selectivity. The results demonstrate the feasibility of cortisol assay in clinical testing and in drug monitoring. 相似文献
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A novel method for immobilizing antibodies (antigens) based on magnetic nanoparticles has been proposed for piezoelectric immunoassay. The goat-anti-IgG antibody (IgGAb) as the model analyte was first covalently immobilized to magnetic nanoparticles, which were surface modified with amino-groups. The magnetic bio-nanoparticles (MBN-s) formed were attached to the surfaces of quartz crystal with the help of a permanent magnet. The detection of immunoglobulin G (IgG) was performed with the sensor prepared. The process of immobilization and immunoreaction was monitored by frequency recording. From the SEM images of the sensor surface before and after immobilization of MBN, one can see that the MBN was homogeneously adsorbed on sensor surface. The piezoelectric immunosensor can determine IgG in the range of 0.6-34.9 μg ml−1 with a detection limit of 0.36 μg ml−1. The MBN and immunocomplex layer can easily be removed simply by taking away the magnetic field, making the piezoelectric sensor easy to be regenerated. 相似文献