金纳米棒对SPR生物传感器灵敏度的增强效应

研究不同长径比的金纳米棒对表面等离子体共振(SPR)生物传感器灵敏度的增强效应.利用晶种生长法合成不同长径比的金纳米棒,并对其形貌、光学性质进行表征.采用双抗体夹心法,以金纳米棒 与羊抗人IgG的偶联体作为第二抗体,利用实验室自行研制的波长调制SPR生物传感器对人IgG进行测 试.实验结果表明:不同长径比的金纳米棒...     

一种新型包埋染料的核壳纳米颗粒表面增强共振拉曼探针的研制及其在免疫分析中的应用

应用于生物分析的纳米探针主要包括:等离子体共振颗粒探针,量子点、荧光探针和拉曼探针等等.拉曼探针跟其它纳米颗粒探针相比,其重要的优点是它能提供丰富的分子结构信息,从而很大程度上避免了光谱重叠,有可能研制出各种不同的拉曼探针.特别值得注意的是,基于表面增强与共振增强相结合的纳米拉曼探针,能超灵敏地、高特异性地检测生物分子.该文采用了一种新型的合成方法,成功地制备了以纳米金为核,二氧化硅为外壳,且其中包埋有染料的金/二氧化硅核壳纳米颗粒,并把它作为一种表面增强共振拉曼(SERRS)探针用于免疫分析.     

伴刀豆球蛋白A／葡聚糖修饰的金纳米颗粒自组装膜增强信号的表面等离子体共振葡萄糖传感器

通过特异性识别作用在表面等离子体共振传感器的金膜表面构建了伴刀豆球蛋白A/葡聚糖修饰的金纳米颗粒自组装膜。当有葡萄糖存在时,膜被分解,从而实现对葡萄糖的灵敏检测。结果表明:由于金纳米颗粒和金膜之间的等离子体波耦合作用,修饰了金纳米颗粒的自组装膜上,葡萄糖的检测信号有明显增强。该传感器可以选择性地检测0.1～100mmol/L浓度范围内的葡萄糖溶液,且敏感膜可以多次再生使用。     

功能化硅壳磁性纳米颗粒亲和吸附介质靶向分离蛋白质研究

基于溴化氰修饰方法在硅壳磁性纳米颗粒表面修饰功能性生物分子,获得功能化硅壳磁性纳米颗粒亲和吸附介质.以胰蛋白酶-胰蛋白酶抑制剂作为模式亲和对,基于酶和抑制剂之间的特异性结合原理,首先考察了胰蛋白酶抑制剂的修饰对硅壳磁性纳米颗粒粒径和电位的影响及其修饰效率,然后利用胰蛋白酶抑制剂修饰的硅壳磁性纳米颗粒亲和吸附介质对简单模型蛋白质混合溶液以及胰脏组织中的胰蛋白酶进行靶向分离.该研究基于硅壳磁性纳米颗粒的内核磁性及表面生物修饰,为蛋白质分离提供了一种新型亲和吸附介质.     

基于纳米晶PZT／石英的压电生物质量传感器研究

制作了一种新型的基于纳米晶PZT／石英的压电生物质量传感器。采用了溶胶-凝胶法在石英晶体表面制备了纳米晶PZT薄膜,形成PZrr／石英结构的敏感单元。研究了纳米晶PZT在石英基体上的微观结构、表面形貌;探讨了纳米晶PZT／石英作为敏感单元在细胞检测中的作用。实验结果表明：PZT薄膜的晶粒大小为20-30nm,沿〈101）晶向择优生长,并且,薄膜表面平整,结构致密。纳米晶PZT／石英结构的敏感单元使生物细胞传感器的灵敏度得到了提高。     

基于金纳米颗粒免疫凝集的压电传感技术快速检测人血清免疫球蛋白IgG

发展了一种利用金纳米颗粒免疫凝集的压电传感技术用于人血清免疫球蛋白IgG的简单、快速、高灵敏检测.以金纳米颗粒替代传统胶乳标记羊抗人IgG诊断血清(抗IgG),利用石英晶体微天平(QCM)直接灵敏响虚因金纳米颗粒免疫凝集而引起溶液的非质量参数(密度、粘度等)的变化.考察了pH值、离子强度和抗IgG-金纳米颗粒浓度对免疫凝集反应的影响,并进行了质控实验.结果表明,该传感技术毋需固定活性组分,可快速榆测浓度下限0.38μg/mL的免疫球蛋白IgC.定量能力与经典ELISA法相接近,可基本满足临床疾病诊断的生化检测要求.     

氧化锌纳米棒/单晶硅的酒精传感器研究

首先采用射频溅射在单晶硅(Si)上制备氧化锌(ZnO)薄膜,作为生长ZnO纳米棒的晶种层,再在水热条件下生长ZnO纳米棒.X射线衍射、X射线能量色散谱,扫描电镜及室温光致发光谱对样品的物相结构、成分、表面微观形貌和晶体缺陷进行了表征.结果表明合成的ZnO纳米棒是六方纤锌矿结构,长径比较高,结晶良好.研究了ZnO纳米棒/单晶Si传感器在空气和酒精气体中的电压-电流(Ⅰ-Ⅴ)特性,阻抗谱及响应-恢复时间.该传感器在+6 V的偏置电压下,其电阻在0.08 g/L酒精气体中下降71%,响应时间小于1 min,可以作为一种新型的酒精气体传感器.     

基于SU-8和AU-S的光纤传感制备及测试

将SU-8光刻胶涂覆在经过表面处理的锥形光纤表面,其表面的环氧基与MPTMS(3-硫丙基三甲氧基硅烷)发生交联作用。TPTMS表面的-SH基与用种子溶液生长法制备的星形纳米颗粒形成很强的化学键AU-S(其能量为170 kJ/mo1)。此外,我们还用这种光纤传感对不同浓度的酒精和甲胆紫溶液进行了透射谱测量。最后测试结果表明这种表面修饰了星形纳米颗粒的光纤传感对不同的物质和浓度非常灵敏,这种纳米光学传感有望被用于高灵敏度的检测中。     

电沉积纳米金修饰钛电极对甲醛的电催化氧化

制备了电沉积纳米金修饰的钛电极(Au/Ti),扫描电镜观察发现钛基体表面纳米金颗粒大小均匀、粒径大约为150～170 nm.运用循环伏安和电位阶跃技术研究了Au/Ti对甲醛的电氧化,Au/Ti电极对甲醛氧化具有良好的电催化活性.0.1 mol/LNaOH溶液中,甲醛浓度0～60 mmol/L范围内,甲醛氧化峰电流与甲醛浓度呈良好的线性关系,检测下限达4.7312×10-7mol/L.     

基于金纳米棒的DNA杂交检测

金纳米棒具有独特的光学性质与良好的生物适应性,在生物医学领域得到了日益广泛的应用.利用种子生长法,通过改变表面活性剂十二烷基二甲基苄基氯化铵(BDAC)的浓度所制备的8种不同长径比(AR)的金纳米棒,具有不同位置的纵向表面等离子共振(SPR)峰.在金纳米棒和非标记探针DNA的混合盐溶液中加入靶标DNA后检测,发现金纳米...     

On-chip fabrication of magnetic alginate hydrogel microfibers by multilayered pneumatic microvalves

Alginate hydrogel has widespread applications in tissue engineering, cancer therapy, wound management and drug/cell/growth factor delivery due to its biocompatibility, hydrated environment and desirable viscoelastic properties. However, the lack of controllability is still an obstacle for utilizing it in the fabrication of 3D tissue constructs and accurate targeting in mass delivery. Here, we proposed a new method for achieving magnetic alginate hydrogel microfibers by dispersing magnetic nanoparticles in alginate solution and solidifying the magnetic alginate into hydrogel fiber inside microfluidic devices. The microfluidic devices have multilayered pneumatic microvalves with hemicylindrical channels to fully stop the fluids. In the experiments, the magnetic nanoparticles and the alginate solution were mixed and formed a uniform suspension. No aggregation of magnetic nanoparticles was found, which is crucial for flow control inside microfluidic devices. By regulating the flow rates of different solutions with the microvalves inside the microfluidic device, magnetic hydrogel fibers and nonmagnetic hydrogel fibers were fabricated with controlled sizes. The proposed method for fabricating magnetic hydrogel fiber holds great potential for engineering 3D tissue constructs with complex architectures and active drug release.     

Electrokinetic motion of single nanoparticles in single PDMS nanochannels

Electrokinetic motion of single nanoparticles in single nanochannels was studied systematically by image tracking method. A novel method to fabricate PDMS-glass micro/nanochannel chips with single nanochannels was presented. The effects of ionic concentration of the buffer solution, particle-to-channel size ratio and electric field on the electrokinetic velocity of fluorescent nanoparticles were studied. The experimental results show that the apparent velocity of nanoparticles in single nanochannels increases with the ionic concentration when the ionic concentration is low and decreases with the ionic concentration when the concentration is high. The apparent velocity decreases with the particle-to-channel size ratio (a/b). Under the condition of low electric fields, nanoparticles can hardly move in single nanochannels with a large particle-to-channel size ratio. Generally, the apparent velocity increases with the applied electric field linearly. The experimental study presented in this article is valuable for future research and applications of transport and manipulation of nanoparticles in nanofluidic devices, such as separation of charged nanoparticles and DNA molecules.     

Nanoparticle synthesis completed with in situ catalyst preparation performed on a high-pressure high-temperature continuous flow reactor

The present communication reports a three-way strategy on utilizing a newly developed continuous high-pressure, high-temperature micro-fluidic reactor to synthesize and modify nanoparticles (NPs) and produce catalytically relevant materials in one flow. Well-defined platinum nanoparticles have been synthesized within a few seconds and in a highly controlled fashion. By changing the applied temperature, flow rate and the type of solvent, the size and the surface morphology of the resulting nanoparticles was changed and tuned on-the-fly. It was also shown that the primarily synthesized NPs can be successfully modified further by using them as seeds in the same flow from where they were formed, by applying the seeded growth method, which resulted in increased particle size and the formation of well-defined but randomly distributed shapes. Furthermore, after synthesizing, the Pt nanoparticles were adsorbed onto the surface of well-known support materials in the same flow to provide in situ production of commercially relevant Pt/SiO₂ catalysts. The in situ prepared catalytically active materials were tested in the hydrogenation of cinnamaldehyde and showed high activity.     

纳米Fe3O4表面聚合接枝的XPS分析

采用在纳米Fe3O4颗粒表面通过引入过氧基因引发甲基丙烯酸甲酯(MMA)聚合的方法,在纳米Fe3O4颗粒表面接枝了PMMA.采用傅立叶红外光谱(IR-FT)检测粉体表面官能团,采用X射线光电子能谱(XPS)检测粉体表面化学键变化,采用高分辨透射电镜(HRTEM)观察改性后粉体的表观形貌.结果表明纳米Fe3O4呈球形,颗粒间团聚不明显,在纳米Fe3O4表面成功地包覆了PMMA,PMMA以化学接枝的方式结合在Fe3O4颗粒表面.     

Pt石墨烯-碳纳米管修饰玻碳电极对甲醛的电催化氧化

该文首先制备了石墨烯-碳纳米管复合材料,然后通过水热法将Pt纳米粒子修饰于该复合材料表面,制成了Pt／石墨烯（Graphene,Gr）-碳纳米管（Carbonnanotubes,CNTs）／玻碳电极（Glassycarbonelectrode,GCE）传感器。在磷酸盐缓冲溶液（pH=2．3）中利用循环伏安法研究了甲醛在Pt／Gr—CNTs／GCE上的电化学行为。实验结果表明,Pt／Gr-CNTs对甲醛具有良好的电催化氧化作用。     

Effects of nanoparticles on the nucleation and devitrification temperatures of polyol cryoprotectant solutions

To investigate the efficiency of nanoparticles as nucleation agents in polyol cryoprotectant solutions at cryogenic temperatures, the nucleation and devitrification temperatures of these solutions with different concentrations of diamond, gold, copper–nickel, and silicon nanoparticles were measured through differential scanning calorimetry. The results show that ice growth in these cryoprotectant solutions is prominently accelerated by nanoparticles and the devitrification temperatures of cryoprotectant solutions are significantly lowered by nanoparticles. These findings can be used to improve the efficiency of cell cryopreservation procedures and open numerous avenues of investigations regarding the application of nanoparticles in cryogenics.     

基于质量屋的轨道车辆设计流程研究与分析

结合质量屋的搭建分析理念和轨道车辆的设计流程,设计了一套适用于轨道车辆质量屋的搭建与分析流程,鉴于方案阶段的质量屋是轨道车辆研发、生产的基础,详细介绍了方案阶段质量屋的搭建流程。流程从需求收集、整理、提炼开始,然后根据客户需求确定解决方案,并在方案中将RAMS技术指标作为重要的工程控制措施,经过整理、提炼和质量屋分析,最终确定关键控制要点和产品可靠性增长的方案,为下一级质量屋确定重点工作方向。通过案例分析验证了方案设计质量屋流程的工程化过程。     

改进同伦分析方法及推广Kuramoto Sivashinsky方程的近似解

首先介绍了带有两个辅助参数的改进同伦分析方法,然后用该方法得到了推广Kuramoto-Sivashin-sky方程的同伦近似解.所得近似解与精确孤立波解进行比较,发现本文得到的近似解更有效地逼近真实解.因为该解包含了两个辅助参数,所以能够更有效地调节和控制其收敛区域和速度.研究表明带有两个辅助参数的改进同伦分析方法对复杂非线性系统的研究更有它的优点.