扫描近场光学显微镜及其在单分子探测中的应用

扫描近场光学显微镜在光学显微镜中具有独特的性能,其突破衍射光限制,具有单分子探测灵敏度,且在研究时不损伤生物样品。文中简要介绍了扫描近场光学显微镜的原理,详述近年来扫描近场光学显微镜在单分子探测中的应用,介绍了扫描近场光学显微镜结合量子点对单分子探测的进展,并对单分子探测的前景做了展望。     

近场光学纳米技术及其应用

本文介绍近场光学纳米技术在近场扫描光学显微镜、分子激发子显微镜和亚波长光纤化学传感器方面的应用，展望了这一重要技术的最新的发展方向。     

利用扫描近场光学显微镜的偏振衬度对各向异性微晶的观察

利用扫描近场光学显微镜的偏振衬度对罗丹明6G的微晶进行观察,结果表明,用圆偏振入射光进行观察时,光学图像与表面形貌图有很好的对应关系。而用线偏振入射光进行观察时,随着入射偏振态的不同,成像差别较大:当偏振态方向沿着具有各向异性吸收的晶粒主吸收方向时,在垂直于主吸收方向上有很高的衬度,但图像分辨率较低;而入射偏振态垂直于主吸收方向时,衬度降低,分辨率提高;在与主吸收方向成45°角入射时,可以得到分辨率和衬度都比较好的图像。     

利用AFM和SNOM对淋巴细胞膜表面超微结构及其光学性质的初步研究

利用原子力显微镜(Atomic Force Microscopy，AFM)对淋巴细胞表面形貌进行了形态学的初步研究，观察到了其膜表面其他显微技术所不能发现的超微结构．同时也运用扫描近场光学显微镜(Scanning Near field Optical Microscopy，SNOM)对淋巴细胞进行成像，观察了其对光的透射、吸收等光学性质，并对两种成像方法进行了比较．研究发现：淋巴细胞膜表面凹凸不平，分布着大量直径几十到几百纳米不等的小颗粒；淋巴细胞中央部位有自发荧光现象．结果表明，AFM和SNOM可作为进一步探讨淋巴细胞的结构与功能关系的有力工具．     

有机非线性光学晶体NPP的AFM研究

有机二阶非线性光学活性晶体的分子设计和晶体工程是复杂而又引人注目的课题．有机非线性光学晶体N一忡硝基苯基）－LWe脯氨醇（NPP）是一个极为成功的自］子山．由于在＊＊P分子中引入了含手性碳原子和可形成分子间氢键的电子给体脯氨醇，使得其分子跃迁偶极矩与单科P21晶体结构的二重轴之间的夹角为586”．接近于理论优化值（54．74”），因此，＊＊P具有很高的宏观二阶非线性光学活性，其粉末二次谐波强度为尿素的150倍．自1984年首次报导以来，对它的晶体生长门和物理性质已进行了广泛深入的研究．原子力显微镜（＊＊M）能够以极高…     

飞秒时间分辨光学多道谱仪研究

超快时间分辨光谱学为研究非线性光学，固体物理，化学反应动力学，能量传递和驰豫、生物过程动力学和相干光谱技术提供了一种有效的工具。本文报导了一种飞秒时间分辨光学多道光谱设备，该设备是由一台用氩离子激光器原浦且产生１００ｆｓ光脉冲并调谐在７２０－９８０ｎｍ的飞秒掺钛兰宝石激光器，改进了光学多道器（ＯＭＡ－ＩＩ），３８６计算机及光学系统组成的。激光脉冲用ＬＢＯ晶体倍频，谱仪装置的时间分辨率约１２０ｆｓ，     

《单细胞分析》

单细胞分析是分析化学、生物学和医学多学科相互渗透发展形成的跨学科前沿领域。 分析化学新方法新技术丛书——《单细胞分析》，由武汉大学程介克教授等著。全书共分15章，全面系统地介绍了单细胞分析的各种方法，包括毛细管电泳、微流控芯片、多种光学显微镜（荧光显微镜、聚焦荧光显微镜、全内反射荧光显微镜、多光子荧光显微镜、荧光相关显微镜、近场扫描光学显微镜等）、扫描电化学显微镜、质谱成像、原子力显微镜、扫描隧道显微镜图像分析、阿达玛变换显微光谱及成像、肿瘤电化学及免疫分析、动力学分析、荧光及发光探针、纳米技术以及实时动态检测等新技术和新方法。     

干细胞迁移机理的近场扫描光学显微术研究

将内皮细胞生长因子(VEGF)置于甲基纤维素碟中形成VEGF的浓度梯度分布,并将人脐带间充质干细胞(Mesenchymal stem cells,MSCs)于此浓度梯度中培养,观察VEGF能否诱导MSCs定向迁移。应用近场扫描光学显微术(Near-field scanning optical microscopy,NSOM)同时获取了VEGF诱导前后的MSCs的形貌和光学信息。结果表明,近场光学图观测到形貌图上所没有的黑色斑点,分析认为这些黑斑为细胞的黏着斑。近场光学图显示经过VEGF诱导后细胞的黏着斑数量明显增加。同时,对诱导前后干细胞的骨架蛋白进行免疫荧光标记并用共聚焦显微镜进行观察,结果表明细胞骨架由诱导前的无序状态转变为诱导后的有序状态,说明诱导后的干细胞处于迁移状态。光学超微结构图则显示了诱导后干细胞表面的光学细节比诱导前细胞大量增加,出现了大量直径约200 nm的光斑,这是由于细胞表面大量分泌黏附分子等蛋白分子引起的,这些结果为VEGF能够诱导MSCs进行定向迁移提供了实验依据和可视化证明。也表明NSOM不但能提供高分辨的光学分辨率,还可提供生物细胞精细结构的更深层次的光学信息。     

聚苯胺／聚氯乙烯和聚苯胺聚甲基丙烯酸甲酯复合物薄膜三阶非线性光学效应

聚苯胺／聚氯乙烯和聚苯胺聚甲基丙烯酸甲酯复合物薄膜三阶非线性光学效应欧阳萌，龚克成（华南理工大学高分子材料系广州５１０６４１）莫党，王惠，林位株（中山大学物理系广州５１０２７５）关键词聚苯胺复合物，光学透过率，三阶非线性光学效应对于具有共轭双键结构的...     

金配合物[Au（C=C-4-LNO2）（PPh3）二阶非线性光学性质的理论研究

用含时密度泛函理论组合态求和方法研究实验合成的金配合物[Au（C≡C-4-LNO2）（PPh3），L=-C6H4（1），-C5H3N（2）]和自行设计的金配合物[Au（C≡C-4-CdH：N2NO2）（PPh3）L=-C4H2N2]（3）的非线性光学性质．计算结果表明，3个配合物的二阶非线性性质变化规律为β1〈β2〈β3，与芳香性的变化规律正好相反．3个配合物的频率色散理论计算结果与实验观测值不符，暗示着晶体合成时的晶胞排列方式是影响体系宏观NLO性质的关键因素之一．     

A simple self-assembly method for colloidal photonic crystals with a large area

Colloidal photonic crystals were fabricated using polystyrene particles (180 nm) and PMMA particles (450 nm), respectively, with a new and simple self-assembly method without special equipment. SEM images indicate that the prepared samples have ordered structures with few defects. The position of the stop-band scale nicely agrees with the particles' size. The sintering process of the PS photonic crystal film was studied with AFM heating system.     

Inverse opal photonic crystal of chalcogenide glass by solution processing

Chalcogenide opal and inverse opal photonic crystals were successfully fabricated by low-cost and low-temperature solution-based process, which is well developed in polymer films processing. Highly ordered silica colloidal crystal films were successfully infilled with nano-colloidal solution of the high refractive index As(30)S(70) chalcogenide glass by using spin-coating method. The silica/As-S opal film was etched in HF acid to dissolve the silica opal template and fabricate the inverse opal As-S photonic crystal. Both, the infilled silica/As-S opal film (Δn ~ 0.84 near λ=770 nm) and the inverse opal As-S photonic structure (Δn ~ 1.26 near λ=660 nm) had significantly enhanced reflectivity values and wider photonic bandgaps in comparison with the silica opal film template (Δn ~ 0.434 near λ=600 nm). The key aspects of opal film preparation by spin-coating of nano-colloidal chalcogenide glass solution are discussed. The solution fabricated "inorganic polymer" opal and the inverse opal structures exceed photonic properties of silica or any organic polymer opal film. The fabricated photonic structures are proposed for designing novel flexible colloidal crystal laser devices, photonic waveguides and chemical sensors.     

高热稳定性氟化聚醚砜的合成及其在阵列波导光栅复用器中的应用

用合成的3-三氟甲基苯侧基聚醚砜(3F-PES)作为波导芯层材料制作了新型硅基聚合物阵列波导光栅(AWG)复用器.采用DSC,TGA和AFM等方法对3F-PES的光学性质和热稳定性进行了表征.DSC和TGA结果显示,3F-PES的玻璃化转变温度为170℃,在空气中5%的热失重温度为542℃,表明具有非常好的热稳定性.3F-PES溶液在旋涂时具有很好的成膜性,AFM照片显示,粗糙度起伏为0.35nm.近红外吸收谱表明,3F-PES在光通讯波段有较小的吸收,适合用来制作低损耗的光波导器件.用3F-PES作为波导芯层材料制作的八通道硅基聚合物阵列波导光栅(AWG)复用器的通道间隔为1.603nm,中心波长为1550.15nm.     

Scanning near-field optical microscopy

Scanning near-field optical microscopy (SNOM) has become a widespread technique due to its promising ability of imaging with sub-micron resolution. Despite being developed over more than one decade, SNOM is still not a mature technique, which can be seen from the large number of recent publications describing instrumentational innovations. However, there are also many applications of near-field microscopy to the observation of thin organic film systems, which are supplementary to other techniques and demonstrate the usefulness of the technique.     

1,4-双二茂铁噻吩/纳米二氧化锡异质结光伏性质研究

运用LB技术制备了1,4-双二茂铁噻吩与纳米二氧化锡复合膜异质结.用AFM和XRD分别表征了纳米二氧化锡和异质结的成膜特性以及二氧化锡的物相结构;用紫外可见吸收光谱和表面光电压谱(surface photovoltage spectra, SPS)对其光吸收和光伏性质进行了研究,发现复合膜异质结在紫外可见光区(300～550 nm)有很好的光伏性能,相对于单一薄膜材料的光伏响应范围有一定程度的拓展,而且响应强度也有较大提高.     

Superhydrophobic perpendicular nanopin film by the bottom-up process

We first fabricated the superhydrophobic film with a water contact angle of 178 degrees based on a perpendicular nanopin fractal structure by a bottom-up process. Until now, only materials with an original water contact angle larger than 90 degrees , which is classified as hydrophobicity, could be used to fabricate the superhydrophobic film (>170 degrees ) according to the possible fractal structure by a top-down process. Now, in this work, a water contact angle of about 178 degrees can be achieved using a lauric acid-coated film with an original contact angle of 75 degrees , which is classified as hydrophilicity, based on an ideal fractal structure for the superhydrophobic surface which is fabricated by the nanosize pin with 6.5 nm diameter.     

Surface-guided self-assembly of silver nanoparticles on edges of heterogeneous surfaces

A general method for the generation of two-dimensional (2D) ordered silver nanoparticles (av 45 nm) ring array has been demonstrated via controllable self-assembly. The selective self-assembly is conducted on the edges of a gold coated polyelectrolyte film. This film is fabricated using the monolayer polystyrene (PS) spheres (av 600 nm) on a substrate as template, followed by depositing a positively charged polyelectrolyte and gold colloids (av 17 nm) via the layer-by-layer (LbL) self-assembly technique, and finally by eliminating the PS monolayer. This gold coated polyelectrolyte film has a regular pattern of sharp edges, and those edges are composed of abundant polyelectrolyte. This heterogeneous surface is easily prepared and universal for site-selective absorption of nanoparticles (silver nanoparticles in this paper, av 45 nm). This surface-guided self-assembly is powerful for fabricating micro/nanostructures on the edges of prepatterns. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to characterize the products.     

亚微米级叉指型超微带电极阵列的加工和电化学表征

超微电极具有常规电极无法比拟的优良的电化学特性.超微电极包括单超微电极和超微电极阵列,单超微电极响应电流较小,一般仪器难以检测;而超微电极阵列除具有单超微电极的特点外,还能增加测量时的响应电流,有利于仪器检测.其中的叉指型超微带电极阵列(IDA)具有产生-收集效应,可提高检测的灵敏度,实现低浓度测量[1～4].将微电子技术和微细加工技术应用于化学和生物传感技术已引起关注,利用微细加工技术可以实现传感器的微型化、集成化和智能化;减少测量使用的样品量;使传感器的敏感元件具有确定的形状和尺寸,提高测量结果的一致性.本文用多…     

Surface-enhanced Raman scattering and micro-Raman imaging of Langmuir-Blodgett films of rhodium phthalocyanine

Rhodium phthalocyanine (RhPc) was synthesized and ultra thin Langmuir-Blodgett (LB) films of RhPc were successfully fabricated. The LB film characterization was carried out using both UV-vis absorption spectra and Raman scattering. The Raman spectroscopy was carried out using 633 and 780 nm laser lines. LB films were deposited onto Ag nanoparticles to achieve the surface-enhanced pre-resonance Raman scattering (pre-SERRS) and surface-enhanced Raman scattering (SERS) for both laser lines, respectively, which allowed the characterization of the RhPc ultra thin films. The morphology of the LB RhPc neat film is extracted from micro-Raman imaging.     

Facile synthesis and photoelectrochemical performance of the bush-like ZnO nanosheets film

Bush-like ZnO nanosheets film is fabricated on conductive transparent oxide substrates using a facile hydrothermal method without any surfactant or further heat treatment. The morphology, structure and photoluminescence property of the products are characterized in detail. The ZnO nanosheets are composed of numerous grains with the 5 nm average diameter, and most of the sheets present the relative uniform arrangement. These nanosheets construct a porous network which is favorable for the photoelectrochemical properties and applications in dye-sensitized solar cells. The photoelectrochemical performances of the bush-like ZnO nanosheets film are investigated, and a high open-circuit voltage of 0.69 V is achieved.