An Inverted Surface Plasmon Resonance

Abstract

An inverted surface plasmon resonance is observed by measuring the internal reflectivity of a bilayer chromium-gold thin film deposited on a high index glass prism. With incident transverse magnetic radiation and suitable choice of chromium and gold thicknesses a strong resonance maximum is recorded which is nearly as narrow as the more commonly observed surface plasmon resonance minimum for gold. A peak reflectivity of order 40% has been recorded which with fine adjustment of the film thickness may be increased to perhaps 80% although it never approaches 100% because of the intrinsic absorption by the chromium. The angle dependent reflectivity data obtained are analysed using a multilayer Fresnel equation model and optical field and power loss profiles through the resonance are presented to illustrate its nature.     

Surface Plasmon Resonance Imaging Measurements of Electrostatic Biopolymer Adsorption onto Chemically Modified Gold Surfaces

A combination of in situ and ex situ surface plasmon resonance (SPR) imaging experiments is used to characterize the differential electrostatic adsorption of proteins and synthetic polypeptides onto photopatterned monolayers at gold surfaces. The nonspecific electrostatic adsorption of proteins onto negatively charged self-assembled monolayers (SAMs) of 11-mercaptoundecanoic acid (MUA) is found to depend on the protein pI, solution ionic strength, and solution pH. The pH dependence of the electrostatic adsorption of the protein avidin onto a MUA SAM indicates that a full monolayer adsorbs at a solution pH greater than 5.0, and an "effective pK(a)" of 3.6 is determined for the avidin adsorption. This effective pK(a) is a combination of the pK(a) of the MUA monolayer and the ion pairing adsorption coefficient for the avidin. Additional SPR imaging experiments show that the electrostatic adsorption of the synthetic polypeptide poly-l-lysine (PL) onto a MUA SAM varies with molecular weight, forming a full PL monolayer for polypeptides with more than 67 lysine residues.     

Exploitation of Localized Surface Plasmon Resonance

Recent advances in the exploitation of localized surface plasmons (charge density oscillations confined to metallic nanoparticles and nanostructures) in nanoscale optics and photonics, as well as in the construction of sensors and biosensors, are reviewed here. In particular, subsequent to brief surveys of the most‐commonly used methods of preparation and arraying of materials with localized surface plasmon resonance (LSPR), and of the optical manifestations of LSPR, attention will be focused on the exploitation of metallic nanostructures as waveguides; as optical transmission, information storage, and nanophotonic devices; as switches; as resonant light scatterers (employed in the different near‐field scanning optical microscopies); and finally as sensors and biosensors.     

差分表面等离激元共振传感仿真研究

从薄膜光学理论出发,对不同金属膜厚度、不同实折射率和不同复介电常数的环境介质的表面等离激元共振(SPR,Surface Plasmon Resonance)信号进行了分析,给出了最佳金属膜厚度,并且,折射率与共振角呈线性关系(R=0.999 4).分析了采用差分处理时,随环境介质的复介电常数变化的光反射率曲线.结果表明,同组两个探测器信号的和随环境介电常数的虚部变化,与实部无关,其信号差则相反,因此,能够同时测量环境介质的介电常数的实部和虚部.     

基于GGBP蛋白绑定的表面等离子共振葡萄糖浓度测量

人体糖尿病的微创检测是通过测量人体表皮组织液中的葡萄糖浓度,来预测人体血液中的葡萄糖浓度.采用表面等离子共振（SPR）技术,并使用对葡萄糖有特异性吸附的D-半乳糖/D-葡萄糖结合蛋白（GGBP）,研究组织液测试的方法.实验中针对不同的GGBP蛋白配置了不同浓度的葡萄糖溶液.将突变蛋白（E149C）,（E149C,A213S）和（E149C,A213S,L238S）分别绑定在传感器上.实验结果表明,使用不同蛋白质修饰过的表面等离子共振传感器,能够测量不同浓度范围的葡萄糖溶液,其中GGBPE149（E149C为突变位点）有最高的灵敏度,在测量葡萄糖水溶液浓度0.5mg/L～5mg/L时有较好的线性.实验结果显示了GGBP蛋白在糖尿病检测及其他人体组织成分检测领域的良好应用前景.     

温度对表面等离子体振荡传感器的作用

本文采用棱镜型角度检测的方法,对表面等离子体振荡传感器进行精密检测.首先从理论上分析了温度对棱镜型表面等离子体传感器的作用机理,并根据机理进行了实验系统的设计.基于所设计的棱镜型角度检测SPR装置,研究了温度对表面等离子体振荡(SPR)共振角度的影响.实验给出了表面等离子体共振角度随被测液体温度的升高而下降的数值结果,斜率为-7.843×10-3/℃,并证明了温差控制对光传感技术中表面等离子体振荡(SPR)技术的实用化的重要性.     

用于食品安全检测的便携式表面等离子体共振生物传感器

针对食品安全检测,构建了一种角度扫描型便携式表面等离子体共振生物传感器。详细介绍了光学系统、硬件电路及软件设计。并以盐酸克伦特罗(瘦肉精的一种)为检测样品,通过在传感器芯片固定生物探针,对浓度分别为2 mg/L、4 mg/L、8 mg/L、16 mg/L和32 mg/L的盐酸克伦特罗抗体进行了连续检测实验。实验结果符合生物分子免疫反应规律,证明了该装置的可行性。该装置便携、易操作,在食品安全检测领域具有广泛应用前景。     

贵金属纳米颗粒的表面等离子共振研究

通过修正的Mie理论分别对单金属Ag、单金属Cu和Cu核Ag壳纳米颗粒/玻璃复合材料的吸收光谱进行了理论计算.计算结果表明,对单金属Ag纳米颗粒/玻璃复合材料,Ag的吸收峰位于425nm左右,不随颗粒尺寸变化而发生偏移;对单金属Cu纳米颗粒/玻璃复合材料,Cu的吸收峰也不随尺寸变化发生偏移但强度较弱;对Cu核Ag壳纳米...     

光纤表面等离子体共振传感系统的数据处理

针对表面等离子体共振原理以及光纤传感的优越特性,本文提出并实现了一种基于光纤表面等离子体共振效应的传感检测系统,给出了系统数据分析的处理模型.该方法根据偏度-峰值检验,采用高斯分布检验对共振区域附近的测试数据进行了均值处理,通过理论分析进一步指出采用均值估计的线性模型可以有效地估计共振波长;同时,在保证检测精度的前提下给出了数据处理的最小运算长度.结果表明,可以使系统数据计算的工作量降低至原来的2%,从而提高了系统的处理效率.     

局域表面等离子体共振效应气体传感器的研究进展

贵金属纳米结构的局域表面等离子体共振光学在光催化、光学传感器、表面增强光谱学、太阳能电池等领域具有广阔的应用前景。基于贵金属的局域表面等离子体共振效应传感器的性能主要依赖于贵金属的结构,总结了纳米贵金属粒子性质以及各种结构的制备方法和应用,并展望了未来表面等离子体共振效应传感器的发展趋势。     

System-on-Chip Circuit Architecture for Eliminating Interferents in Surface Plasmon Resonance Sensing Systems

This paper presents a system-on-chip circuit architecture that enables the extraction of concentration information directly from a surface plasmon resonance (SPR) probe, independent of ambient fluctuations in the reference medium, temperature, and background light. Compensation for these baseline (bulk) interferences is embedded into the baseline integration state of the photodetectors in the optical path, creating a ldquoflat linerdquo for the baseline [no analyte present/bulk refractive index (RI)] condition and the characteristic SPR dips for the measurement (analyte present) condition. A resolution of 2 times 10^-4 RI units is possible with this system, comparable to the 5 times 10^-4 RI unit resolution of conventional signal processing (software-based) approaches to processing the same data using a similar framework. This approach demonstrates experimentally the capability of the dip-based SPR probe in a portable footprint for detecting RI at resolution levels suitable for practical applications of these probes to field environments.     

Multi-Wavelength-Recognizable Memristive Devices via Surface Plasmon Resonance Effect for Color Visual System

Photoelectric memristor has attracted many attentions thanks to their promising potential in optical communication chips and artificial vision systems. However, the implementation of an artificial visual system based on memristive devices remains a considerable challenge because most photoelectric memristors cannot recognize color. Herein, multi-wavelength recognizable memristive devices based on silver(Ag) nanoparticles (NPs) and porous silicon oxide (SiO_x) nanocomposites are presented. Rely on the effects of localized surface plasmon resonance (LSPR) and optical excitation of Ag NPs in SiO_x, the set voltage of the device can be gradually reduced. Moreover, the current overshoot problem is alleviated to suppress conducting filament overgrowth after visible light irradiation with different wavelengths, resulting in diverse low resistance states (LRS). Taking advantage of the characteristics of controlled switching voltage and LRS resistance distribution, color image recognition is finally realized in the present work. X-ray photoelectron spectroscopy (XPS) and conductive atomic force microscopy (C-AFM) show that the light irradiation plays an important role on resistive switching (RS) process: the photo-assisted Ag ionization leads to a significant reduction of set voltage and overshoot current. This work provides an effective method toward the development of multi-wavelength-recognizable memristive devices for future artificial color vision system.     

差分式强度检测型表面等离子共振传感器的研究

针对表面等离子共振(SPR)传感器需要昂贵的角度转动或光谱分析装置的缺点,提出了采用双LD进行差分光强检测折射率变化的方法.该方法基于等离子共振原理,采用两个波长对应的反射光强差来实现对介质折射率变化量的传感,设计了参考光路,以消除光源波动带来的影响.理论分析及实验表明,这种方法比单LD光强检测方法的灵敏度提高了近一倍.由于没有使用角度检测装置及光谱仪,易于实现仪器的小型化.可通过调整入射角和采用不同光源的方法来实现不同区间的折射率测量.     

表面等离子体共振生物传感器在食品安全检测中的应用与研究

表面等离子体共振（SurfacePlasmonResonance,SPR）传感技术是一项新兴的生物化学检测技术,具有无须标记、高速、高灵敏度等特点。日前在化学和生物检测研究中应用日益广泛。本文综述了SPR技术的基本原理及近年来在食品安全领域研究中取得的进展,并展望TSPR技术的发展方向及应用前景。     

基于局域表面等离子体共振效应生物传感器的制备方法及应用

金属纳米颗粒表现出来的局域表面等离子体共振效应被广泛应用于生物传感器领域.综述了局域表面等离子体共振效应的基本原理,对比了局域表面等离子体和表面等离子体的异同,详细介绍了胶体化学平板印刷术、电子束光刻法、聚焦离子束光刻法、纳米球光刻术等多种金属纳米颗粒阵列和图形制备技术、特点及应用,分析了局域表面等离子体共振生物传感器的应用前景、现存问题及其解决途径.     

金属纳米颗粒在表面等离激元共振生物传感器上的应用

文章研究不同形状和长径比的金属纳米颗粒应用在表面等离激元共振（SPR）生物传感器中对传感信号的影响,自制金属纳米颗粒并进行物理表征,以金纳米颗粒与抗兔IgG进行生物偶联,利用自制角度检测型SPR生物传感器对兔IgG抗体进行检测,结果表明,金属颗粒的形状和长径比对SPR传感器的共振角都有影响,金纳米棒能够明显提高SPR生物传感器的检测灵敏度。     

Localized Defects on Copper Sulfide Surface for Enhanced Plasmon Resonance and Water Splitting

Surficial defects in semiconductor can induce high density of carriers and cause localized surface plasmon resonance which is prone to light harvesting and energy conversion, while internal defects may cause serious recombination of electrons and holes. Thus, it is significant to precisely control the distribution of defects, although there are few successful examples. Herein, an effective strategy to confine abundant defects within the surface layer of Cu_1.94S nanoflake arrays (NFAs) is reported, leaving a perfect internal structure. The Cu_1.94S NFAs are then applied in photoelectrochemical (PEC) water splitting. As expected, the surficial defects give rise to strong LSPR effect and quick charge separation near the surface; meanwhile, they provide active sites for catalyzing hydrogen evolution. As a result, the NFAs achieve the top PEC properties ever reported for Cu_xS‐based photocathodes.     

Fiber-Optic Sensors Based on Surface Plasmon Resonance: A Comprehensive Review

Since the introduction of optical fiber technology in the field of sensor based on the technique of surface plasmon resonance (SPR), fiber-optic SPR sensors have witnessed a lot of advancements. This paper reports on the past, present, and future scope of fiber-optic SPR sensors in the field of sensing of different chemical, physical, and biochemical parameters. A detailed mechanism of the SPR technique for sensing purposes has been discussed. Different new techniques and models in this area that have been introduced are discussed in quite a detail. We have tried to put the different advancements in the order of their chronological evolution. The content of the review article may be of great importance for the research community who are to take the field of fiber-optic SPR sensors as its research endeavors.