Many-Body Terms in van der Waals Cohesion Energy of Nanotubes

We have developed a model for the calculation of van der Waals force for layered systems with axial symmetry. Our result can be applied to compute the cohesion of a carbon nanotube to a substrate, the cohesion between nanotubes, and between shells of multiwall nanotubes. We have obtained unusal power laws for the distance dependence of the many-body van der Waals potential.     

A localized surface plasmon resonance based immunosensor for the detection of casein in milk

In this research, a localized surface plasmon resonance (LSPR) immunosensor based on gold-capped nanoparticle substrate for detecting casein, one of the most potent allergens in milk, was developed. The fabrication of the gold-capped nanoparticle substrate involved a surface-modified silica nanoparticle layer (core) on the slide glass substrate between bottom and top gold layers (shell). The absorbance peak of the gold-capped nanoparticle substrate was observed at ∼520 nm. In addition, the atomic force microscopy (AFM) images demonstrated that the nanoparticles formed a monolayer on the slide glass. After immobilizing anti-casein antibody on the surface, our device, casein immunosensor, could be applied easily for the detection of casein in the raw milk sample without a difficult pretreatment. Under the optimum conditions, the detection limit of the casein immunosensor was determined as 10 ng/mL. Our device brings several advantages to the existing LSPR-based biosensors with its easy fabrication, simple handling, low-cost, and high sensitivity.     

Measurement of metal nanolayers optical parameters using surface plasmon resonance method

The results of experimental definition of optical parameters of silver nanolayers by the method of surface plasmon resonance (SPR) are described. The goniometric installation for measurement of angular dependences of reflection of light by layered nanosructures at the attenuated internal reflection (angular spectrum of reflection) is designed. Calculation of optical parameters of nanolayers is executed taking into account the form of a curve of tin angular spectrum of reflection. The text was submitted by the authors in English.     

基于表面等离子体共振传感器的尿微量白蛋白检测

检测尿微量白蛋白(MAU)可对轻微肾脏损害进行早期诊断,也可对高血压患者可能发生的心脑血管事件进行预测。实验将抗体通过巯基自组装固定于Au膜表面,研制了一种快速检测MAU的表面等离子体共振(SPR)生物传感器。结果表明:直接检测法可以检测到0.3μg/L的MAU,而纳米Au放大法检测限可以低至0.03μg/L。     

Surface plasmon resonance evaluation of various aminoglycoside-RNA hairpin interactions reveals low degree of selectivity

Aminoglycoside antibiotics, which are able to selectively bind to RNA, are considered to be an important lead in RNA-targeting drug discovery. In this study, surface plasmon resonance (SPR) was employed to explore the interaction of aminoglycosides with known tobramycin-binding RNA hairpins (aptamers) and an unrelated RNA hairpin. It was established that aminoglycosides have multiple interactions with RNA hairpins. Unexpectedly, the different hairpins showed comparable affinity for a set of related aminoglycosides. The observed absence of selectivity presents an extra hurdle in the discovery of novel aminoglycosides as specific drugs that target defined RNA hairpins.     

应用SPRI技术检测指纹上的化学品残留

介绍了表面等离子体共振成像（ SPRI）的原理,应用自行搭建的SPRI系统采集指纹图像,并分析其中的化学物残留。在实验中,测量了粘有TiO2颗粒的指纹和正常状态下的指纹的SPR吸收光谱,并进行比较分析。实验结果表明：指纹图像有较高的分辨率和对比度;通过对指纹图像进行SPR分析,获得其SPR图谱,能显著观察到其共振波长的变化,从而能实现对残留化学品的检测。     

基于迈克尔逊干涉仪的SPR传感器的研究

研究了一种基于迈克尔逊干涉仪干涉成像的新型表面等离子体共振(Surface Plasmon Resonance,SPR)传感器,介绍了系统的构建方法和工作原理。系统以溴钨灯为迈克尔逊干涉仪的光源产生干涉图像,采用Kreschmann棱镜耦合结构激励SPR,由CCD摄像机采集传感芯片干涉图,对干涉图进行信息提取和傅里叶变换得到光谱图,再对光谱图进行分析处理得到SPR曲线。在系统中引入了辅助定标光路,即以一已知波长的单色光(氦氖激光器)作为标尺确定光强随光程差变化的干涉图函数中采样点的选取,降低了使用迈克尔逊干涉仪过程中的转动和传动机械误差。实验结果表明,该传感系统具有成本低、结构简单、操作方便、多通道检测等优点。     

Signal enhancement of surface plasmon resonance-based immunoassays for the allergen detection

A surface plasmon resonance (SPR) biosensor was used to determine the recombinant group 1 house dust mite allergen (rDer f1) in both HBS-EP buffer and fetal bovine serum (FBS). The monoclonal antibody was immobilized onto the CM5 sensor chip surface using an amine coupling method. The procedures of antibody immobilization and the subsequent primary and enhanced immunoassay were monitored in real time. The sensitivity for rDer f1 detection was remarkably improved by using intact polyclonal antibody as signal amplifying agent. Using this signal enhanced SPR immunosensor, rDer f1 in HBS-EP buffer and FBS was detected at a concentration of 15.4 and 32.1 ng/ml, respectively. The result demonstrates that SPR biosensor is a simple and reliable method for allergen detection.     

The fabrication of functional biosurface composed of iron storage protein, ferritin

A functional biosurface applicable to a biomemory device was fabricated using ferritin, which is one of the globular protein complexes consisting of 24 protein subunits, which can be classified as metalloproteins. For the fabrication of uniform ferritin layer, 11-MUA(11-mercaptoundecanoic acid) was used as a linker material. The formation of the ferritin layer was confirmed by surface plasmon resonance (SPR) spectroscopy, and the morphology of the immobilized ferritin was analyzed by scanning tunneling microscopy (STM). The electrochemical redox property investigation was accomplished by the cyclic voltammetry (CV) technique. These results of adsorbed ferritin on the modified electrode can be used for the fabrication of bioelectronics.     

飞秒激光在6H-SiC表面诱导偏振依赖纳米结构特性研究

激光诱导偏振依赖纳米结构是一种有效实现纳米图案化的技术,并且一直备受研究者的青睐。利用飞秒激光微加工技术,对6H-SiC晶体表面激光诱导偏振依赖纳米结构特性进行了研究。通过改变入射激光加工偏振态和延迟时间样品表面诱导产生了直径约为150 nm的球形纳米颗粒、椭圆形纳米颗粒和空间周期约为150 nm的高空间频率表面条纹结构。实验结果表明,入射激光偏振特性会直接影响诱导产生的微结构形貌,并且优先入射的飞秒激光对最终产生的表面微结构形貌有决定性作用。初步探讨了偏振依赖纳米结构形成的物理机制,表面等离激元(surface plasmon polariton, SPP)在表面微纳米结构的产生过程中扮演着重要角色,研究结果对激光诱导表面周期结构(laser-induced periodic surface structures, LIPSS)可控制备具有重要意义。