基于光学异常透射现象的光纤传感器的设计与研究

基于光学异常透射现象的光纤传感器,因其具有高度的近场增强效应和介电环境的高度敏感性等优点,在化学、生物医学等领域有广泛的应用前景。但是由于在光纤端面加工周期纳米结构需要复杂的工艺或者昂贵的微加工仪器,限制了基于光学异常透射现象的光纤传感器的发展。针对这一问题,提出了模板转移法在光纤端面加工金属周期纳米结构,并搭建实验系统对应用该方法制作的光纤传感器的传感特性及其物理机理进行了研究。实验结果表明,模板转移法能够很好地完成在光纤端面加工高质量的周期金属纳米结构。应用该方法制作的光纤传感器具有很好的传感特性,传感器的最高灵敏度达到594.45 nm·RIU-1,品质因数值达到33.12。     

荧光过氧化氢酶纳米传感器的制备及性能（英文）

过氧化氢(H_2O_2)是活性氧类的主要标志物,它与多种疾病如神经退行性疾病密切相关。本文设计了一种检测细胞内过氧化氢的荧光过氧化氢酶纳米传感器。这种纳米传感器由含多聚赖氨酸、辣根过氧化物酶的生物相容性外壳和含有氧探针的多孔聚合物基质的氧传感核组成。辣根过氧化物酶(HRP)催化H_2O_2生成氧,进而通过荧光氧气探针进行探测。该酶纳米传感器的流体动力学尺寸约为270 nm,zeta电位为-18 mV,具有良好的生物相容性。它的荧光比率和时间分辨荧光均对H_2O_2高度敏感。此外,该纳米传感器可以被活细胞有效地摄取,从而可以用TRF方式灵敏地检测细胞内的H_2O_2浓度。结果表明,本实验制备的酶纳米传感器有望进一步用于监测H_2O_2相关的细胞生化反应,如氧化应激。     

基于金纳米棒放大的高灵敏度纳米光纤生化传感器

为满足生物医学领域对传感器灵敏度和特异性的要求,利用金纳米棒对纳米光纤消逝场强的消光作用,提出基于金纳米棒标记放大的锥形光纤生化传感器。通过理论计算金纳米棒对光纤传输特性的影响,设计实验证明纳米光纤具有对单个金纳米棒的响应能力。采用双抗夹心法对PBS溶液中的羊IgG检测,检测下限可达0.02ng/mL,证实此种传感器具有极高的灵敏度和特异性。提出的纳米光纤生化传感器结构简单、响应迅速、成本低廉,在医学临床诊断、食品安全检测、环境监测领域具有重要的实用价值。     

基于拉曼光谱技术的甲状腺疾病检测的研究

基于光学成像与光谱技术的无损检测是生物医学光学交叉领域研究的重要发展方向。其中拉曼光谱技术可获得检测对象的生化成分的“指纹信息”,被广泛应用于面向生物分子,细胞以及生物组织的检测诊断研究。甲状腺疾病尤其肿瘤的临床检测往往涉及多方法和技术手段的结合,且存在一定的诊断难度,因此发展新的检测技术方法具有重要的意义。首先综述了拉曼光谱技术在甲状腺细胞系的单细胞拉曼光谱检测与分析,然后介绍甲状腺病理组织和甲状腺正常组织的拉曼光谱鉴别诊断(特别介绍了本研究小组开展以银纳米粒子为增强基底的甲状腺离体组织SERS光谱研究情况),以及拉曼光谱技术在甲状腺激素等方面的研究概况。最后简要探讨了拉曼光谱技术在该领域的研究应用前景和发展方向。     

金属纳米颗粒等离激元共振增强非线性介质谐波的发展现状

随着纳米加工和制备技术的不断发展,金属纳米粒子的等离激元光学特性已得到了广泛的研究与应用。本文基于金属纳米颗粒等离激元共振特性,分析了金属纳米颗粒等离激元共振对介质谐波的增强机制,综述了该增强机制在近几年所取得的最新研究成果及其在生物成像领域的应用。金属纳米颗粒等离激元共振在增强介质非线性特性领域的发展趋势是从简单的金属纳米颗粒向复杂形状纳米颗粒和金属纳米颗粒组装体的发展,这些新型金属纳米颗粒在非线性光学、生物医学上的疾病诊断和治疗有良好的实际应用前景。     

局域表面等离激元

局域表面等离激元使得贵金属纳米颗粒具有丰富的光学性质,其应用涵盖能源、生物医学、安全、信息、超材料等诸多领域。文章简要介绍局域表面等离激元的基本性质、贵金属纳米结构中的局域表面等离激元共振耦合以及具有局域表面等离激元特性的贵金属纳米结构的一些重要应用。     

十字星形金属纳米粒子的消光性质

单纳米粒子的LSPR光学生物传感器具有空间分辨率高, 可植入生物的细胞和组织里, 检测所需要的剂量少等优势。本文提出一种十字星形的纳米粒子结构以进一步提高单纳米粒子LSPR光学生物传感器的信号强度。模拟和分析表明, 十字星形纳米粒子的消光效率远远高于相同结构尺寸的菱形或三角形纳米粒子的消光效率, 为发展新型结构单或阵列式的金属纳米粒子LSPR光学生物传感器提供了参考依据。     

太赫兹超材料生物传感器的应用研究进展

太赫兹（THz）波,是指频率范围在0.1～10 THz的电磁波,在电磁波谱中处于红外与微波之间。太赫兹波的光子能量相对于可见光更低,1 THz对应的能量大约只有4.14 meV,意味着这将大大减少对生物体内组织器官的辐射而引起的伤害,不会对生物分子产生电离。因此,该波段在基础科学、人体安检、危险品检测、高速通信和医学成像等领域具有重要的潜在应用价值。但在医药和生物探测的应用中,通常需要检测微量的分析物,这就需要更高的灵敏度和检测的准确度。但是现存的检测方法受到太赫兹波强度检测可靠性不高的影响。基于超材料的生物传感可以通过增强局域电磁谐振,实现亚波长分辨,大大提高了传感器的分辨率与灵敏度,引起了人们的广泛关注。超材料是一种人工设计的周期性结构,通过合理设计可以增强局域电磁谐振响应,实现亚波长分辨,大大提高传感器的分辨率与灵敏度。太赫兹超材料传感器为生物传感领域提供了一种新的检测方法,具有灵敏度高、响应速度快、无标记检测等优点。随着微纳加工技术的快速发展,制作超材料太赫兹传感器的成本不断降低,从而在生物医学领域具有非常大的潜在应用价值。基于超材料的太赫兹传感器的研究已成为目前一个非常热门的国际前沿方向。但是关于太赫兹超材料传感器的最新研究进展未见报道,为此通过大量搜集并整理相关资料,综述了太赫兹超材料传感器在各种生物探测场景中的最新应用,分别从医学诊断、食品安全、农药检测等方面展开介绍。最后,对太赫兹超材料在生物传感器的发展和应用前景进行了总结和展望。该研究将为人们充分掌握太赫兹超材料生物传感器的最新应用进展提供重要参考,同时为太赫兹超材料传感器的发展和应用提供方向性的指导。     

表面等离激元——机理、应用与展望

等离激元光子学(plasmonics)的研究内容是金属纳米结构独特的光学性质及其应用.随着纳米科技的进步,等离激元光子学已经迅速发展成为一门新兴学科,在生物、化学、能源、信息等领域具有重要的应用前景.文章主要介绍表面等离激元(surface plasmons,SPs)的一些基本物理性质,包括局域的表面等离激元(localized surface plas-mon,LSP)和传导的表面等离激元(propagating surface plasmon polariton,SPP),文章还介绍了表面等离激元的几个重要的应用方向,例如生物/化学传感器、表面等离激元激光、光开关器件以及表面等离激元光逻辑运算,等等.     

光电化学生物传感器研究

光电化学法是在光照射下,将化学能转换为电能的低成本方法。而光电化学生物传感技术由于具有通过生物分子氧化产生的光电流来检测生物分子的能力而引起了广泛的关注。光电化学生物传感器具有低成本、高灵敏度、高特异性、仪器操作简单以及检测背景信号低等特点,在免疫检测和生物技术等重要领域具有广泛应用前景。近年来,对于光电化学生物传感器性能和检测方法的研究也取得了颇丰的成果。本文主要介绍光电化学生物传感器的概念及基本原理、分类应用及对其未来的展望。     

Silver-coated near field optical scanning microscope probes fabricated by silver mirror reaction

In this paper, a silver-coated fiber optic nanoprobe is fabricated using silver mirror reaction. Effects of different coating conditions on thickness, uniformity and optical properties of the coated nanoprobes are investigated. In comparison to thermal vacuum evaporation methods, the approach in this work is simpler, less expensive, more reproducible and particularly suitable for coating a long nanoprobe with a low taper angle. While the silver coating is characterized by high uniformity and good stability, the coated nanoprobe demonstrates great optical properties and capability of [Ca²⁺] detection in a single smooth muscle cell, rendering promising potential applications for optical biosensors in intracellular/intercellular biological substrate detection for single cell analysis. PACS  07.79.Fc; 87.85.Rs; 87.85.Ox     

Inductively Coupled Plasma Optical Emission Spectrometry in the Vacuum Ultraviolet Region

Abstract

Inductively coupled plasma optical emission spectrometry has been applied for trace metal determination in a myriad of sample types. However, the detection of nonmetals is a challenge. For example, the high excitation energies associated with most nonmetals is a barrier for populating the excited state of these elements. Even in the presence of sufficient excitation energy, the principal resonance lines for nonmetals usually lie in the vacuum ultraviolet region, where atmospheric species like oxygen and water vapor absorb the radiation. Several nonmetals (nitrogen, oxygen, and carbon) are also present in the atmosphere, so contamination or background emission signals can hinder quantification. A common approach to solving these problems is to increase throughput by purging the optical path with an inert gas. In addition, unnecessary mirrors or lenses are eliminated when possible. This review provides a survey of the applications of inductively coupled plasma optical emission spectrometry in the vacuum ultraviolet region, with particular emphasis on the detection of sulfur, phosphorus, iodine, and carbon. The alternative of employing nonresonance lines for these elements in the near-infrared region is discussed briefly as well.     

Interface Colloidal Deposition of Nanoparticle Wire Structures

Inspired by natural dewetting phenomena, such as the coffee‐ring effect, researchers are developing strategies for the controlled assembly of colloidal particles into functional nanoparticle conglomerates. Colloidal assembly techniques are regarded as green methods as they reduce or eliminate the use or generation of hazardous substances involved in other manufacturing modalities. This review discusses several recent developments in interface colloidal deposition for preparing nanoparticle wires and integrated nanoparticle wire arrays. Moreover, this review covers real applications of these structures for electric detection of chemical and biological molecules among other functions.     

Plasmonic nanoparticles and their analytical applications: A review

Plasmonic nanoparticles (NPs) have been reviewed herein for their fascinating optical properties in a wide spectral range and for their various applications. The surface plasmon resonance (SPR) bands of metal NPs can be tuned from visible to near infrared region by varying the shape of the metal NPs. As a result, the tuning of the SPR band over a spectral range is possible by making plasmonic NPs of different shapes. This review emphasizes fundamental studies of plasmonic NPs and nanocomposites with well-defined and controlled shapes that have several analytical applications such as molecular detection and determination in different fields. This review describes how oxidative etching and kinetic control can be utilized to manipulate the shape and optical properties of NPs. This review also describes the specific examples of the sensing applications of the localized surface plasmon resonance studies in which the researchers use both wavelength shift and surface-enhanced Raman scattering sensing to detect the molecules of chemical and biological relevance. The review ends with a perspective of the field, identifying the main challenges to be overcome and suggesting areas where the most promising developments are likely to happen in future.     

All-optical mass sensing with coupled mechanical resonator systems

With the small mass, large quality-factor and high frequency, mechanical resonators (MRs) will ultimately find usage in a broad range of applications, such as electrometry, optomechanical/electromechanical signal processing, and mass detection. In this review, we focus on a particular MR application: mass sensing in an all-optical domain. Compared to the mass detection based on the electrical techniques, we have proposed an optical protocol to weigh the external particles deposited onto the surface of a mechanical resonator. This protocol, which is so far the first method to deal with the mass sensing in an all-optical domain, is based on some coupled mechanical resonator systems. Here we review our recent optical mass sensors comprehensively. These all-optical mass sensors have the potential to break through the limitation of frequency restriction and to enhance the sensitivity of mass detection.     

Acoustic radiation force optical coherence elastography for elasticity assessment of soft tissues

Biomechanical properties of soft tissues are important indicators of tissue functions which can be used for clinical diagnosis and disease monitoring. Elastography, incorporating the principles of elasticity measurements into imaging modalities, provides quantitative assessment of elastic properties of biological tissues. Benefiting from high-resolution, noninvasive, and three-dimensional optical coherence tomography, optical coherence elastography (OCE) is an emerging optical imaging modality to characterize and map biomechanical properties of soft tissues. Recently, acoustic radiation force (ARF)–OCE has been developed for elasticity measurements of ocular tissues, detection of vascular lesions, and monitoring of blood coagulation based on remote and noninvasive ARF excitation to both internal and superficial tissues. Here, we describe the advantages of the ARF–OCE technique, the measurement methods in ARF–OCE, the applications in biomedical detection, current challenges, and advances. ARF–OCE technology has the potential to become a powerful tool for in vivo elasticity assessment of biological samples in a noncontact, noninvasive, and high-resolution nature.     

Industrial and medical applications of fiber Bragg gratings(Invited Paper)

The uses of optical fibers are numerous, and over the past few decades, they have extended from optical fiber communications to a wide variety of sensing applications. In particular, fiber Bragg grating(FBG) sensors inscribed in single-mode optical fibers offer significant advantages over more conventional electrical sensors and have been successfully deployed in many different industries. In this Review, we review the applications of intrinsic FBG pressure and flow sensors in oil and gas and the deployment of FBG sensing networks in railways.The promising prospect of using polymer FBGs in wearable medical devices is also described.     

Lights,action: Optical tweezers

Optical tweezers were first realized 15 years ago by Arthur Ashkin and co-workers at the Bell Telephone Laboratories. Since that time there has been a steady stream of developments and applications, particularly in the biological field. In the last 5 years the flow of work using optical tweezers has increased significantly, and it seems as if they are set to become a mainstream tool within biological and nanotechnological fields. In this article we seek to explain the underpinning mechanism behind optical tweezers, to review the main applications of optical tweezers to date, to present some recent technological advances and to speculate on future applications within both biological and non-biological fields.     

Speciation Analysis of Mercury in Aquatic Environment

Abstract

This review considers methods for mercury speciation with low limits of detection that can be applied to real aquatic environmental samples (waters, sediments, biological tissues). Special attention is given to the necessity of clean sampling procedures and the proper storage of the samples. In this review, different extraction techniques for sediments and biological tissues are considered. The performance of different separation techniques, like liquid chromatography and off‐line and on‐line gas chromatography, are compared for their environmental applications.     

Radical detection in harsh environments by means of laser-induced fluorescence using a single bidirectional optical fiber

A new experimental method is described enabling detection of hydroxyl radicals (OH) by laser-induced fluorescence in high-temperature gas-phase reactions. This is accomplished by means of a bidirectional optical fiber probe, which is of interest for applications where optical access is limited. An optical setup that allows simultaneous excitation and detection of fluorescence using one and the same fiber has been developed. Complications resulting from coupling as well as laser-induced scattering are addressed, and different fibers are compared with regard to core material composition and geometric collection efficiency. On this basis, a suitable fiber is identified, and OH detection and profile measurements are demonstrated in a premixed laminar flame as reference experiment.