基于表面等离子体共振成像的指纹采集

指纹识别技术是方便、可靠、非侵害和价格低廉的生物识别技术。为提高图像的质量,根据表面等离子体共振(SPR)的原理,提出采用表面等离子体共振成像(SPRI)采集指纹图像的方法。介绍了表面等离子体共振成像采集指纹图像的原理、自行组建的表面等离子体共振成像指纹采集系统的结构。采用Kretschmann型棱镜耦合结构激励表面等离子体共振,偏振的平面光经棱镜投射到传感片,发生表面等离子体共振现象。由CCD摄像机采集反射光指纹图像。分别用表面等离子体共振成像方法和传统光学方法采集了同一指纹的图像。两图中主要区域指纹脊和谷的对比度分别为0.2014和0.0516。表面等离子体共振成像方法采集的指纹图像的对比度和清晰度显著提高。     

表面等离子共振成像非标记微阵列芯片检测

采用表面化学修饰的镀金玻片作为芯片基质,结合微阵列点样分配技术,设计制作了1种非标记寡核苷酸检测芯片和1种非标记蛋白检测芯片,使用自行构建的表面等离子共振成像(SPRI)检测仪器,成功实现了对寡核苷酸靶标和抗体靶标的非标记、高通量检测分析,研究了核酸和蛋白分子的特异性相互作用,并使用微珠有效增强了芯片的检测信号.     

All thermal-evaporated surface plasmon enhanced organic solar cells by Au nanoparticles

Au nanoparticles (NPs) are fabricated on indium-tin-oxide substrates by a thermal evaporation method and incorporated to an efficient small molecule organic solar cell (OSC). This renders an all thermal evaporated surface plasmon enhanced OSC. The optimized device shows a power conversion efficiency of 3.40%, which is 14% higher than that of the reference device without Au NPs. The improvement is mainly contributed to the increased short-circuit current which resulted from the enhanced light harvesting due to localized surface plasmon resonance of Au NPs and the increased conductivity of the device.     

Optical Nonlinearity of Surface Plasmon Resonance Emission from Au Colloidal Nanoparticles

Suspended gold nanoparticles have been synthesized via electrochemical method.Fluorescence excitation and emission spectra were obtained using a spectrofluorophotometer.With varying the excitation wavelength,an emission peak fixed at 485 nm has always been observed.We believe that this peak is attributed to the surface plasmon resonance.When the detection wavelength was fixed at 485 nm (0.619×10 15 Hz),a double frequency exciting peak at 242 nm(2×0.619×10 15 Hz), a 3/2 fraction frequency exciting peak at 330 nm (about 3/2×0.619×10 15 Hz)and a 3/4 fraction frequency exciting peak at 640 nm(3/4×0.619×10 15 Hz)display.The nonlinear exciting peak at 640 nm corresponds to the two-photon absorption.Therefore,as the excitation wavelength is at 320 and 640 nm respectively,single-photon and two-photon absorption induced surface plasmon resonance emission peaks were observed. These nonlinear surface plasmon resonance emission characters of Au colloidal nanoparticles make it possible to enhance the sensitivity of conventional surface plasmon resonance device.     

Power conversion efficiency enhancement of organic solar cells by addition of gold nanostars,nanorods, and nanospheres

The effects of gold (Au) nanoparticles (NPs) with different morphologies (star, rod, sphere) incorporated into buffer layer, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), of polymer-based organic solar cells (OSCs) were investigated. Solar cells having gold nanoparticles exhibited significant improvement in device efficiency relative to the reference device. The observed improvement is most likely due to the surface plasmon and enhanced light reflection and scattering properties of the Au NPs. The power conversion efficiency (PCE) is increased ca. 29% with Au nanostars, ca. 14% with Au nanorods and 11% with Au nanospheres compared to the device with no Au NP (reference device). Au nanostars provide the strongest contribution to the efficiency among all NP morphologies studied as they have large size, sharp features, and strongest localized surface plasmon resonance effect associate with their morphology.     

Cooperative plasmon enhanced organic solar cells with thermal coevaporated Au and Ag nanoparticles

Cooperative plasmon enhanced small molecule organic solar cells are demonstrated based on thermal coevaporated Au and Ag nanoparticles (NPs). The optimized device with an appropriate molar ratio of Au:Ag NPs shows a power conversion efficiency of 3.32%, which is 22.5% higher than that of the reference device without any NPs. The improvement is mainly contributed to the increased short-circuit current which resulted from the enhanced light harvesting due to localized surface plasmon resonance of Au:Ag NPs and the increased conductivity of the device. Besides, factors that determining the performance of the Au:Ag NPs cooperative plasmon enhance organic solar cells are investigated, and it finds that the thickness of MoO₃ buffer layer plays a crucial role. Owing to the different diameter of the thermal evaporated Au and Ag NPs, a suitable MoO₃ buffer layer is required to afford a large electromagnetic enhancement and to avoid significant exciton quenching by the NPs.     

A plasmonically enhanced polymer solar cell with gold–silica core–shell nanorods

We report the use of chemically synthesized gold (Au)–silica core–shell nanorods with the length of 92.5 ± 8.0 nm and diameter of 34.3 ± 4.0 nm for the efficiency enhancement of bulk heterojunction (BHJ) polymer solar cells. Silica coated Au nanorods were randomly blended into the BHJ layers of these solar cells. This architecture inhibits the carrier recombination at the metal/polymer interface and effectively exploits light absorption at the surface plasmon resonance wavelengths of the Au–silica nanorods. To match the two plasmon resonant peaks of the Au–silica nanorods, we employed a low bandgap polymer, poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b′] dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT) to construct a solar cell. The absorption spectrum of PCPDTBT:[6,6]-phenyl-C₇₁-butyric acid methyl ester (PC₇₀BM) is relatively wide and matches the two plasmon resonance peaks of Au–silica nanorods, which leads to greater plasmonic effects. We also constructed the poly(3-hexylthiophene):[6,6]-phenyl-C₆₁-butyric acid methyl ester (P3HT:PC₆₀BM) cells for comparison. The absorption spectrum of P3HT:PC₆₀BM only overlaps one of the plasmon resonance peak of Au–silica nanorods. The efficiency of the P3HT:PC₆₀BM device incorporating optimized Au–silica nanorods is enhanced by 12.9% from 3.17% to 3.58%, which is due to the enhanced light absorption. Compared with the P3HT:PC₆₀BM device with Au–silica nanorods, the PCPDTBT:PC₇₀BM device with 1 wt% Au–silica nanorods concentration has a higher efficiency of 4.4% with an increase of 26%.     

多通道光纤SPR光谱成像实时监测系统

提出一种多通道光纤表面等离子体共振(SPR)光谱 成像实时监测系统,利用iHR550成像光谱仪和Synapse面阵CCD(1024pixels×256pi xels)并行采集多个独立检测通道完整的光谱信息,保持单通道SPR传感器高分辨率优势的 同时实现多通道检测。基于LabVIEW虚拟仪器,开发了控制iHR550成像光谱仪衍射光栅转台 转动,Synapse CCD分区域数据处理和SPR数据处理的实时监测系统。     

金属表面等离激元增强聚合物太阳电池

研究了Au纳米颗粒表面等离激元增强聚噻吩(P3HT)与富勒烯衍生物(PCBM)共混体系聚合物太阳电池的光电转换效率。Au纳米颗粒表面由双十烷基二甲基溴化铵(DDAB)修饰,能够均匀分散在活性层中。研究了Au纳米颗粒的质量分数对电池性能的影响,发现质量分数为1.2%时,电池性能最佳,转换效率高达3.76%,较未掺杂的参比电池相对提高约20%。掺入Au纳米颗粒后P3HT和PCBM共混膜光吸收显著增强,从而使电池外量子效率大大增加。电池效率的提升主要归结于Au纳米颗粒表面等离激元激发所引起的近场增强。     

The Spaser Nanolaser

The article presents an overview of a surface plasmon resonance laser. Surface plasmon resonance nanolasers, or spasers, are the smallest lasers yet made, and the device could pave the way toward ultrafast optical computing.     

Efficient handover measurement technique for small‐cell networks using a virtual cell synchronization signal

A small‐cell network (SCN) constructed by splitting a macro‐cell into numerous small cells using an active antenna array system is studied. A synchronization signal appropriate for the SCN, virtually generated by an eNodeB with 3D beamforming, is proposed for efficient handover in SCNs. The virtual cell synchronization signal (VCSS) carries a macro‐cell ID (MCID) and virtual‐cell ID (VCID) in a hierarchical manner, allowing us to distinguish between an intra‐cell handover (virtual cell handover within a cell without changing the serving eNodeB) and inter‐cell handover (virtual cell handovers across cells while changing the serving eNodeB) in SCNs. Using the signal metrics obtained by the VCSS, an efficient handover measurement technique is proposed which can significantly reduce the processing time and overhead by distinguishing between the intra‐cell/inter‐cell handovers. The performance of the proposed technique is evaluated by simulating two different deployment scenarios of LTE‐based SCN with 3D beamforming. Copyright © 2017 John Wiley & Sons, Ltd.     

基于色相算法的表面等离子体共振成像传感器

本文报道了一种基于色相算法的彩色表面等离子体共振(SPR)成像传感器,该传感器不仅能够对发生于SPR芯片表面的物理化学反应进行直观的图像观测,还能基于色相算法对这些表面反应进行定量分析。利用自制的波长/图像同步检测型SPR传感器,实验获得了不同共振波长对应的共振图像,然后借助色相算法求得每一幅共振图像对应的二维色相分布及其平均色相,建立了共振波长与图像平均色相的依赖关系,用于优化基于色相参数的SPR折射率灵敏度。实验选择起始共振波长为650nm,测得基于色相的折射率灵敏度为3 338/RIU,是基于共振波长的折射率灵敏度的1.49倍。利用彩色SPR成像技术能够直观地观测到金膜表面涂布的聚四氟乙烯薄膜的不均匀性,再通过计算图像局部区间的平均色相,可以定量获得不同薄膜厚度对应的折射率灵敏度。实验结果证明了基于色相算法的彩色SPR成像传感器明显优于常规SPR传感器。     

Memory design using a one-transistor gain cell on SOI

A 512-kb memory has been developed featuring a one-transistor gain cell of size 7F/sup 2/ (F = 0.18 /spl mu/m) on SOI. The cell named the floating body transistor cell (FBC) has the ability to achieve a 4F/sup 2/ cell using self-aligned contact technologies and is proved to be scalable with respect to a cell signal. A basic operation was verified by device simulation and hardware measurement. An array driving method is disclosed which makes selective write possible. A cell signal sensing system consisting of a pair of reference cells written opposite data and comparing the combined current with the doubled cell current is shown to be robust against cell parameter variations in process and temperature. A random access time of 40 ns was simulated. Nondestructive readout and C/sub b//C/sub s/. free signal development drastically improve cell efficiency.     

分子印迹膜SPR传感器检测氯磺隆的方法

研究使用了中国科学院电子学研究所自行研制的高灵敏度单通道SPR分析仪和进样装置,仪器为棱镜耦合型SPR传感器结构,其检测角度范围是40°～70°,折射率检测范围为1.04～1.47,谐振角的精度在0.001°。适用于SPR分析仪的分子印迹芯片采用PVC-MIP共聚膜法制备,SPR角度扫描结果表明,200nm以下厚度芯片具有较好的SPR吸收特性。以氯磺隆为模板的分子印迹膜与不加氯磺隆的分子印迹膜对比实验发现前者具有特异性结合的能力。实验对浓度0.1,0.2,0.5和1μg/mL的氯磺隆进行了SPR定点检测,这四种浓度氯磺隆的折射率响应信号满足线性关系,相关系数R=0.996 4。实验中对低浓度的氯磺隆进行反复检测,检测到50ng/mL的氯磺隆,满足农残检测的要求。     

Plasmon‐Enhanced Photodetection in Ferromagnet/Nonmagnet Spin Thermoelectric Structures

The photothermoelectric (PTE) effect that originates from the temperature difference within thermoelectric materials induced by light absorption can be used as the mechanism for a light sensor in optoelectronic applications. In this work, a PTE‐based photodetector is reported using a spin thermoelectric structure consisting of CoFeB/Pt metallic bilayers and its signal enhancement achieved by incorporating a plasmonic structure consisting of Au nanorod arrays. The thermoelectric voltage of the bilayers markedly increases by 60 ± 10% when the plasmon resonance condition of the Au nanorods is matched to the wavelength of the incident laser. Full‐wave electromagnetic simulations reveal that the signal enhancement is due to the increase in light absorption and consequential local heating. Moreover, the alignment of the Au nanorods makes the thermoelectric voltages sensitive to the polarization state of the laser, thereby enabling the detection of light polarization. These results demonstrate the feasibility of a hybrid device utilizing plasmonic and spin‐thermoelectric effects as an efficient PTE‐based photodetector.     

Dynamics of Strong Coupling between J‐Aggregates and Surface Plasmon Polaritons in Subwavelength Hole Arrays

A prototypical hybrid system formed by strong coupled gold hole arrays and J‐aggregate molecules is investigated by using both steady‐state spectroscopic method and ultrafast pump‐probe approach. In particular, the plasmonic response of the device has been tuned by modifying its periodicity thus to achieve the strongest possible coupling regime. It is found that in the transient absorption spectra, under upper band excitation, the bleaching signal from uncoupled J‐aggregate molecules completely disappears. Instead, two distinctive period dependent bleaching bands are formed, clearly fingerprint of the hybrid exciton‐plasmon state. The dynamics of these bands is also directly analyzed. A remarkable long lifetime is found especially for the upper band, corresponding to the presence of a trap state in its transient absorption spectra under resonance excitation. Such unique feature should provide a new approach to control quantum‐mechanical states under coherent coupling.     

基于光纤SPR传感器水中盐度的测定

论述了检测系统和基于拉锥技术的光纤表面等离子共振(SPR)传感器的详细设计.制定了基于SPR的光纤传感器检测水样品的盐度的比较方案,以满足一些实践需求,诸如精度,速度快,小尺寸和高灵敏度折射率单位(RIU).利用Matlab和C++仿真得到了每个参数对光纤拉锥SPR传感器系统设计性能的影响,这为设备参数的合理选择提供了理论依据.设计了一种新的检测系统,将光学、机械和电子技术相结合.根据拉锥技术、模场分析理论及初步实验结果表明,该装置基本上达到了设计要求,如小巧、便携、良好的线性度和高度单位折射率.基于这个新设备对具有不同的盐度的NACL-水混合物进行了SPR实验,实验结果表明,可以实现对单个样品的精确检测.其谐振波长分辨率可以达到0.15 nm,同时,该检测结果具有较高的线性度和良好的稳定性,折射率(RI)检测偏差小于0.002.     

基于表面等离子体共振和双频激光干涉相位测量的空气折射率测量

设计了一种基于表面等离子体共振和相位检测的空气折射率实时测量系统,该系统采用双频激光外差干涉光路和具有角漂移自适应结构的表面等离子体共振传感器。理论分析表明测量光信号的p、s分量的相位差相对于参考光信号的变化与空气折射率近似呈线性关系,并由此得到测量公式,传感器的自适应结构将角漂移引起的误差降低了一个数量级并大幅提高了测量灵敏度。与Edlen公式的测量比对实验结果表明,在44.0°入射角(共振角附近)和0.1°的相位测量精度下,空气折射率的测量精度优于5×10-6。该测量系统还可为更高精度的空气折射率测量仪提供足够精确的初值。     

Tuning Specific Biomolecular Interactions Using Electro‐Switchable Oligopeptide Surfaces

The ability to regulate biomolecular interactions on surfaces driven by an external stimuli is of great theoretical interest and practical impact in the biomedical and biotechnology fields. Herein, a new class of responsive surfaces that rely on electro‐switchable peptides to control biomolecular interactions on gold surfaces is presented. This system is based upon the conformational switching of positively charged oligolysine peptides that are tethered to a gold surface, such that bioactive molecular moieties (biotin) incorporated on the oligolysines can be reversibly exposed (bio‐active state) or concealed (bio‐inactive state) on demand, as a function of surface potential. The dynamics of switching the biological properties is studied by observing the binding events between biotin and fluorescently labeled NeutrAvidin. Fluorescence microscope images and surface plasmon resonance spectral data clearly reveal opposite binding behaviors when +0.3 V or ?0.4 V vs. SCE are applied to the surface. High fluorescence intensities are observed for an applied positive potential, while minimal fluorescence is detected for an applied negative potential. Surface plasmon resonance spectroscopy (SPR) results provided further evidence that NeutrAvidin binding to the surface is controlled by the applied potential. A large SPR response is observed when a positive potential is applied on the surface, while a negative applied potential induces over 90% reduction in NeutrAvidin binding.     

多元等离子体共振纳米结构的飞秒激光加工与拉曼检测应用

以多元金属纳米薄膜(金、银)为基底,利用飞秒激光加工技术制备得到多元等离子体纳米结构,并研究了其局域表面等离子体共振效应(Local Surface Plasmon Resonance,LSPR)和表面增强拉曼散射(Surface Enhanced Raman Scattering,SERS)性能。利用时域有限差分(Finite Difference Time Domain,FDTD)软件模拟了不同情况下(单层金膜、金银双层金属薄膜的平面以及阵列结构)的电场分布情况。根据仿真结果,相较于平面金属膜来说,飞秒激光制备的微纳结构阵列附近区域产生电磁场增强,集中在结构边缘处,且其强度变化与预期结果基本保持一致。此外,使用浓度为10-4 M和10-6 M的罗丹明(R6G)溶液进行SERS性能测试。测试的结果表明,单层平面金膜基本没有SERS峰值信号出现,而单层金膜上制备的等离子体纳米结构附近出现峰值信号,双层金属薄膜上制备的等离子体纳米结构展现出更高的SERS峰值信号。多元金属等离子体纳米结构展示出更强的局域表面等离子体共振效应,从而在表面增强拉曼散射、光催化、生物传感等领域具有广泛的应用。