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.     

局域表面等离子体共振在可视化传感中的应用进展

贵金属纳米材料具有小尺寸效应、表面效应、量子尺寸效应、宏观隧道效应、表面等离子体共振(SPR)和局域表面等离子体共振(LSPR)等物理化学性质,本文阐述了SPR和LSPR产生的机理,并总结了LSPR在可视化传感中的应用进展。     

银纳米球阵列的局域表面等离子体特性研究

基于金属纳米颗粒的光散射理论,利用时域有限差分法计算了Ag纳米球阵列不同结构参数下的散射光谱、吸收光谱及散射效率,分析了Ag纳米球阵列在共振波长下的极化电场和极化电荷分布情况,讨论了Ag纳米球阵列的局域表面等离子体(LSP)对GaN基LED发光效率增加的机理。结果表明,随着间距的减小,Ag纳米球阵列LSP的散射峰逐渐呈双模分布,且位于长波段的散射峰蓝移;随着Ag纳米球直径的增大,LSP的共振波长红移且散射效率增大。当LSP的共振波长与LED辐射光波长相匹配时,Ag纳米球阵列的LSP与LED辐射光发生耦合作用,在一定条件下,部分耦合的能量辐射到自由空间,增大LED的内量子效率。     

银纳米球阵列的局域表面等离子体特性研究北大核心CSCD

基于金属纳米颗粒的光散射理论,利用时域有限差分法计算了Ag纳米球阵列不同结构参数下的散射光谱、吸收光谱及散射效率,分析了Ag纳米球阵列在共振波长下的极化电场和极化电荷分布情况,讨论了Ag纳米球阵列的局域表面等离子体(LSP)对GaN基LED发光效率增加的机理。结果表明,随着间距的减小,Ag纳米球阵列LSP的散射峰逐渐呈双模分布,且位于长波段的散射峰蓝移;随着Ag纳米球直径的增大,LSP的共振波长红移且散射效率增大。当LSP的共振波长与LED辐射光波长相匹配时,Ag纳米球阵列的LSP与LED辐射光发生耦合作用,在一定条件下,部分耦合的能量辐射到自由空间,增大LED的内量子效率。     

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。     

表面声波气体传感器

引言把表面声波(简称SAW)元件做成气体传感器已于1979年第一次提出。这种传感器的优点是体积小(<0.1cm~3),灵敏度高(可检测到ppm数量级,甚至ppb数量级),价格便宜。 SAW气体传感器的基本原理是在SAW元件的延迟线上覆盖上一层薄膜,被测气体分子通过扩散进入薄膜,或者用物理吸附方法吸附在薄膜上,或者用化学吸附方法吸附     

金属纳米粒子的量子等离子体共振效应研究取得突破

具有纳米尺度的金属纳米粒子在物理、力学等性能方面迥异于块体金属材料,其中以纳米金属粒子的量子等离子体共振效应在纳米光学、生物学、传感器、光谱仪及太阳能的收集等领域具有巨大的潜在应用价值,相关研究一直备受国内外科研人员的关注。在纳米金属粒子的量子等离子体共振效应中,人们以往的研究对象多为     

前驱物和表面活性剂对等离子体电化学法制备银纳米颗粒的影响

利用等离子体电化学法成功制备出银纳米颗粒,并通过局域表面等离子共振效应对颗粒的生长过程进行实时监测,研究了表面活性剂的浓度、种类和前驱物浓度对银纳米颗粒制备的影响。研究结果表明:增大前驱物或表面活性剂浓度对Ag;还原均有促进作用;与聚乙烯吡络烷酮(PVP)和十六烷基三甲基溴化铵(CTAB)相比较,十二烷基硫酸钠(SDS)作为表面活性剂,在相同时间内,生成的银纳米颗粒数量更多,尺寸和形状分布更均匀。     

采用虚拟仪器技术的表面等离子体共振传感器

针对表面等离子体共振(SPR)传感器对精度和数据处理能力的要求,利用虚拟仪器技术,自行设计了一套基于角度扫描的Kretschmann结构SPR测试系统。为了提高折射率的测量分辨力,系统采用了高精度步进电机控制的旋转平台。软件中使用巴特沃思低通滤波器消除出射光干涉噪声引起的高频干扰。同时,提出了一种双棱镜自适应结构对出射光路进行实时调整,实现角度扫描过程中光探测器固定不动。实验测得空气和蒸馏水样品的折射率分别为1.00293和1.33432,结果与理论值基本吻合,且具有良好的重复性和达到10-5RIU(RefractiveIndexUnit)的分辨力。     

基于Fano共振的等离子体共振传感器

基于表面等离子体共振的金属纳米结构传感器具有测量精度高、易集成的特点,已广泛应用于生物、化学、材料、光子学和生命科学等诸多领域。然而由于表面等离子体共振在可见光波段具有较大的辐射损耗,导致等离子体共振传感器谐振峰较宽,极大地限制了传感器的性能。本文采用不对称双椭圆柱结构在等离子体共振传感器中引入不对称性,产生Fano共振以实现窄带光谱特性。通过优化结构参数,在681 nm波长处,得到了半高全宽(FWHM)仅为10.8 nm的谐振谷。该传感器在环境折射率1.0~1.1的变化范围内,折射率灵敏度可以达到299 nm/RIU,品质因数可以达到27.8。该传感器在高折射率灵敏度传感应用方面有着巨大的潜力。     

Reusable Localized Surface Plasmon Sensors Based on Ultrastable Nanostructures

Nanoparticle arrays created by nanosphere lithography are widely used in sensing applications since their localized surface plasmon resonances are extremely sensitive to changes in the local dielectric environment. A major drawback for any biologically oriented sensing application of conventionally produced particle arrays is the lack of stability of the nanoparticles in aqueous media and buffer solutions. Here, a robust and reusable nanoscale sensing platform based on localized surface plasmon resonances of gold nanoparticles embedded in a silicon dioxide matrix is presented. The architecture exhibits extremely high stability in aqueous environments and can be regenerated several times by simple mechanical cleaning of the surface. The platforms surface is ultraflat by design, thus making it an ideal substrate for any bio‐oriented sensing application.     

Localized Surface Plasmon Resonance Enhanced Light Absorption in AuCu/CsPbCl3 Core/Shell Nanocrystals

Localized surface plasmon resonance (LSPR) is shown to be effective in trapping light for enhanced light absorption and hence performance in photonic and optoelectronic devices. Implementation of LSPR in all-inorganic perovskite nanocrystals (PNCs) is particularly important considering their unique advantages in optoelectronics. Motivated by this, the first success in colloidal synthesis of AuCu/CsPbCl₃ core/shell PNCs and observation of enhanced light absorption by the perovskite CsPbCl₃ shell of thickness in the range of 2–4 nm, enabled by the LSPR AuCu core of an average diameter of 7.1 nm, is reported. This enhanced light absorption leads to a remarkably enhanced photoresponse in PNCs/graphene nanohybrid photodetectors using the AuCu/CsPbCl₃ core/shell PNCs, by more than 30 times as compared to the counterparts with CsPbCl₃ PNCs only (8–12 nm in dimension). This result illustrates the feasibility in implementation of LSPR light trapping directly in core/shell PNCs for high-performance optoelectronics.     

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.     

High Spatial Resolution Mapping of Localized Surface Plasmon Resonances in Single Gallium Nanoparticles

Plasmonics has emerged as an attractive field driving the development of optical systems in order to control and exploit light–matter interactions. The increasing interest around plasmonic systems is pushing the research of alternative plasmonic materials, spreading the operability range from IR to UV. Within this context, gallium appears as an ideal candidate, potentially active within a broad spectral range (UV–VIS–IR), whose optical properties are scarcely reported. Importantly, the smart design of active plasmonic materials requires their characterization at high spatial and spectral resolution to access the optical fingerprint of individual nanostructures, attainable by transmission electron microscopy techniques (i.e., by means of electron energy‐loss spectroscopy, EELS). Therefore, the optical response of individual Ga nanoparticles (NPs) by means of EELS measurements is analyzed, in order to spread the understanding of the plasmonic response of Ga NPs. The results show that single Ga NPs may support several plasmon modes, whose nature is extensively discussed.     

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...     

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.     

Growth of Silver Nanowires from Controlled Silver Chloride Seeds and Their Application for Fluorescence Enhancement Based on Localized Surface Plasmon Resonance

A “Polyol” method has granted low‐cost and facile process‐controllability for silver‐nanowire (Ag‐NW) synthesis. Although homogenous and heterogeneous nucleation and growth during Ag‐NW synthesis are possible using polyol methods, heterogeneous nucleation and growth of Ag NW guarantees highly selective growth of nanostructures using silver chloride (AgCl) seeds, which provides a stable source of chloride ions (Cl?) and thermodynamic reversibility. In this paper, a microdroplet has been adopted to synthesize uniform AgCl seeds with different diameter that are used for seed‐mediated Ag‐NW synthesis. The concentration of two precursors (AgNO₃ and NaCl) in the droplets is modulated to produce different sizes of AgCl seeds, which determines the diameter and length of Ag NWs. The process of the seed‐mediated growth of Ag NWs has been monitored by observing the peak shift in the time‐resolved UV–vis extinction spectrum. Furthermore, the distinct plasmonic property of Ag NWs for transverse and longitudinal localized‐surface‐plasmon‐resonance (LSPR)‐mediated fluorescence enhancement is utilized. The high aspect ratio and sharp tips work as simple antennas that induce the enhanced fluorescence emission intensity of a fluorophore, which can be applied in the fields of biological tissue imaging and therapy.     

角度扫描型SPR传感器在免疫反应检测中的数据处理研究

表面等离子体共振(SPR)传感器广泛应用于生物分子的免疫反应检测。针对自行研制的角度扫描型 SPR 传感器,根据Langumair模型开发了动力学检测和动力学数据分析软件系统,提出了一种采用多项式拟合和质心法相结合的数据处理方法,该方法可有效抑制免疫反应检测过程中噪声、环境温度和机械振动等对SPR共振角测量的干扰。检测小鼠抗原、抗体免疫反应动力学,求出其结合速率常数ka≈2.05×104 M-s-、解离速率常数kd≈0.005 s-,验证了该装置和数据处理方法的可行性。该方法能有效提高角度扫描型表面等离子体共振传感器的精度和抗干扰能力,具有良好的应用和推广价值。