交流电沉积制备纳米枝晶拉曼基底

使用交流电沉积方法在预定的微区域内制备了纳米枝晶表面增强拉曼散射基底。通过调节交流和偏置直流电压可以控制基底的形貌、位置以及生长方向。从电化学过程、液电耦合场2个角度对拉曼基底的生长机理进行了阐述。激光共焦显微拉曼实验进一步表明：使用四巯基吡啶作为指针分子,该基底具有良好的拉曼活性。     

纳米金膜对VSCs吸附的研究

研究纳米Au膜在常温下对液态挥发性硫化物(VSCs)的吸附能力,实验采用多种浓度的正丙硫醇作为被检测气体,以不同的Au膜粗糙度和Au膜厚度进行测试,结果发现,在粗糙度p≤1 nm的基底上,Au膜厚度为9~15 nm,吸附后再进行加热处理,Au膜呈现出重复性好的吸附特点。     

一种新型包埋染料的核壳纳米颗粒表面增强共振拉曼探针的研制及其在免疫分析中的应用

应用于生物分析的纳米探针主要包括:等离子体共振颗粒探针,量子点、荧光探针和拉曼探针等等.拉曼探针跟其它纳米颗粒探针相比,其重要的优点是它能提供丰富的分子结构信息,从而很大程度上避免了光谱重叠,有可能研制出各种不同的拉曼探针.特别值得注意的是,基于表面增强与共振增强相结合的纳米拉曼探针,能超灵敏地、高特异性地检测生物分子.该文采用了一种新型的合成方法,成功地制备了以纳米金为核,二氧化硅为外壳,且其中包埋有染料的金/二氧化硅核壳纳米颗粒,并把它作为一种表面增强共振拉曼(SERRS)探针用于免疫分析.     

纳米海绵状SERS芯片 海洋光学有限公司

海洋光学发布了一款全新的纳米海绵状SERS芯片。与同类产品相比,该芯片具有更低的背景噪音、更高的激光功率承受力、更宽的泛波长激光选择和更长的货架仔放期,是拉曼增强的理想选择。海洋光学还提供了不同波段范围的拉曼模块和IDRaman系列（含638nm的拉曼系列）。     

掺杂和热处理对纳米ZnO薄膜气敏特性影响

用真空蒸发法在玻璃和单晶硅片上制备纯Zn和掺杂Zn薄膜，然后在高于450℃条件下进行氧化、热处理（玻璃衬底）获得良好的纳米ZnO薄膜和掺杂ZnO薄膜。对单晶硅衬底上制备的纯Zn薄膜在高于800℃温度条件下进行液态源掺杂，获得掺B和P纳米ZnO薄膜。实验表明，掺杂和热处理使纳米ZnO薄膜的结构、导电性能得到改善，有效地降低了纳米ZnO薄膜的电阻，同时薄膜的气敏特性也得到较大的改善。     

科学家用DNA作为纳米印刷模板

美国Brigham Young大学的科学家们把DNA自组织技术同微制造印刷术结合起来，制造出纳米通道、纳米线和纳米沟等结构．这项发现为目前光学印刷术所达不到的尺寸下的纳米加工开辟了新的路径．研究人员发明了一种利用DNA为模板来定义基底图案的方法．他们把DNA在基底上排列整齐，再在上面沉积一层金属膜．DNA分子起纳米蜡纸的作用，这样来在基底上定义一些小于10纳米的图案．此后研究人员使用半导体工业中常用的活性气体等离子体对图案表面进行各向异性刻蚀，在基底上得到了高纵宽比的沟槽．沟槽的确切尺寸可以通过改变沉积角度和沉积厚度来控制．     

表面增强拉曼光谱在环境分析中的研究进展

表面增强拉曼散射(SERS)效应是一种异常的表面光学效应,其增强因子最大可达到1014～1015.环境污染导致人类生存环境受到严重影响.某些污染物,比如持久性污染物,在环境介质中含量低,毒性大,很少能够直接检测出来.因此必须采用更灵敏的方法和技术.由于SERS效应的高灵敏性,SELLS技术有望成为超灵敏分析环境污染物的一种工具.该文综述了表面增强拉曼光谱在环境污染物检测中的研究进展,并提出SERS传感器将是很重要的发展方向.     

多层纳米银／壳聚糖膜用于芘的表面增强拉曼测定

多环芳烃类物质的高疏水性质使得其在金属表面吸附能力差,从而拉曼增强信号弱。该文针对此问题,制备了以壳聚糖为骨架,纳米银颗粒为热点的多层纳米银／壳聚糖复合膜表面拉曼增强基底,成功用于芘的表面增强拉曼检测。由于壳聚糖本身的富集作用,目标分子被吸附、富集于银纳米颗粒形成拉曼热点,可检测0．01μmol／L的芘。     

中国微米纳米 花状Au-SnO2复合材料的制备及其对甲醛气敏性能的研究

利用水热法合成了花状SnO2微米材料,并以它作为基体,对其进行Au纳米颗粒修饰,得到了花状Au-SnO2复合材料.利用X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)分析等表征手段对所制备的Au-SnO2复合材料进行了表征分析,结果表明,这种花状结构的材料是由厚度为30 nm～60 nm的SnO2纳米片自组装而成,其尺寸为1 μm～2 μm.同时,我们用花状SnO2和Au修饰的花状SnO2复合材料对1×10-6～500×10-6的甲醛进行了气敏性能测试.结果表明,通过Au修饰,花状SnO2对甲醛的气敏性能有了极大的提高.当甲醛浓度为200×10-6时,其灵敏度(Ra/Rg)约为120,是花状SnO2敏感材料的8倍,表现出很高的响应.另外,由Au修饰的花状SnO2复合材料制成的敏感元件对甲醛表现出良好的选择性.这可能归因于Au纳米颗粒高效的催化活性促进了甲醛气体的扩散和O2的吸附,从而使其表现出更加优异的气敏性能.     

纳米碳化硅/硅纳米孔柱阵列湿敏性能研究

以硅纳米孔阵列(Si-NPA)为衬底,采用化学气相沉积法分别制备了SiC纳米颗粒/Si-NPA(nc-SiC/Si-NPA)和SiC纳米线/Si-NPA(nw-Si/Si-NPA)复合体系,并对其表面成分和形貌、室温湿敏性能进行了表征.实验结果表明,nc-SiC/Si-NPA和nw-SiC/Si-NPA均对水蒸气表现出...     

Vertically aligned multi-walled CNT arrays coated by gold nanoparticles for surface-enhanced Raman scattering

A unique substrate for surface-enhanced Raman scattering on vertical multi-walled carbon nanotube (MWCNT) arrays coated by Au nanoparticles was reported. The vertically aligned MWCNT arrays were prepared by thermal chemical vapor deposition at temperature of 720 °C, and then coated by gold nanoparticles by sputtering. The possible mechanisms for the SERS sensitivity were discussed. Raman spectroscopy experiments for detecting Rhodamine6G were carried on and some obvious Raman peaks were observed and analyzed.     

Droplet microfluidic preparation of au nanoparticles-coated chitosan microbeads for flow-through surface-enhanced Raman scattering detection

An integrated microfluidic device was fabricated to enable on-chip droplet forming, trapping, fusing, shrinking, reaction and producing functional microbeads for a flow-through single bead-based molecule detection. Dielectrophoresis (DEP) force was used to transport target polymer droplets into different predefined microwells, where the droplets were fused through electrocoalescence to form a new one with a desired diameter. In a continuous water loss process with water diffusion to oil phase, the polymer droplet was shrunken and solidified to form a polymer microbead. For a demonstration, Au nanoparticles-coated chitosan microbeads were in situ fabricated through droplet trapping, fusion and shrinking, followed by synthesis of Au nanoparticles on the microbead surface via a photoreduction process. The produced Au nanoparticle/chitosan microbead embedded in the microwell resulted in a highly sensitive, flow-through surface-enhanced Raman scattering (SERS) detection of Rhodamine 6G (R6G). This work successfully demonstrates an integrated droplet based lab-on-a chip and its application to fabricate an extremely high-throughput single bead based detection platform.     

目标物诱导的等离子激元耦合以及表面增强拉曼光谱用于牛奶中三聚氰胺的检测

该文报道了一种基于目标物诱导的等离子激元耦合以及表面增强拉曼光谱、利用未修饰的金纳米颗粒检测牛奶中三聚氰胺的新颖、免标记、易操作的纳米生物传感方法。三聚氰胺与聚T寡核苷酸的结合使得金纳米颗粒不稳定,从而导致盐诱导的单分散金纳米颗粒发生团聚。而团聚的金纳米颗粒能够产生等离子激元耦合,并引发了表面拉曼信号的增强。该方法不仅在设计上简单、直接,而且在具体实验操作中也是非常快速和方便的。该方法能够在实际牛奶样品中检测三聚氰胺．检测限为8nmol／L。     

Detecting very small quantity of molecular probes in solution using nano-mechanically made Au-cavities array with SERS-active effect

Well-ordered nano-mechanically made Au-cavities array (nAu) is tailored as a functional surface with high density tip-to-tip cavities, adjustable indentation depths, and a number of edges within the nanostructures. In this study, the nAu was fabricated by a physical way and utilized as a characterization tool with the advantage of preventing samples from chemical or residual contaminations. Two types of molecular probe solutions: 5,5′-dithio-bis-(2-nitrobenzoic acid) (DTNB) and Rhodamine 6G (R6G) were evaluated. For DTNB solution, the chemically adsorbed monolayer was formed upon the nAu, which resulted in the effect of surface enhanced Raman scattering (SERS), mainly induced by the combined chemical and electromagnetic effects. Within the range of 1 × 10⁻²³ to 3.2 × 10⁻²² mole, Raman intensity and the quantity of DTNB molecules exhibited a sharp exponential relationship. For R6G solution within the equivalent nAu and the identical range, the relationship exhibited nearly linear; however, within an extended range of 1 × 10⁻²³ to 3.2 × 10⁻²¹ mole, a moderate exponential relationship was obtained. The enhancement factors for detecting DTNB and R6G solutions using the nAu could be optimized to 1.62 × 10⁸ and 4.60 × 10⁷, respectively.     

Investigation of Raman enhancement in hydrothermally roughened SERS-active substrates

In this work, we study surface enhanced Raman spectroscopy (SERS) active substrates for the detection of Rhodamine 6G. To examine the electromagnetic enhancement, we apply the finite-difference time-domain (FDTD) algorithm to analyze the structures by solving a set of coupled Maxwell's equations (Ampere's Law and Faraday's Law) in differential form. The field enhancements are thus investigated in the visible regime with the wavelength of 633 nm. In our experimental measurement, the surface enhanced Raman scattering signals from the surface of substrates with 12-hour treatment and without treatment are performed and compared. Through the three-dimensional (3D) FDTD calculation, we find that the hydrothermally 12-hour treated samples possess significantly vertical variations of surface and thus have relatively larger field enhancement than those without treated. Consequently, it implies a strong positive effect on the surface enhancement which is consistent with the measured intensity.     

Large-area Raman enhancement substrates using spontaneous dewetting of gold films and silver nanoparticles deposition

We present a cost-effective method for making large-area surface enhanced Raman scattering (SERS) substrates by using spontaneous dewetting of ultrathin gold film. The dewetting of 5-nm-thick gold film formed high-density gold islands ranged from 40 nm to 80 nm. The measured SERS signal was 5 times stronger than synthesised gold nanoparticles. The SERS signals can be further increased by depositing small silver nanoparticles on the dewetted film. The experimental results showed 5-nm-thick silver coating increased SERS signals up to 10 times. The calculations by finite-difference time-domain method verified such SERS enhancement originated from enhanced electric fields between gold islands and silver nanoparticles. In the application, we demonstrated an all-optical measurement of pH values in microfluidic devices by using SERS signals of para-mercaptobenzoic acid.     

Implementation of substrates for surface-enhanced Raman spectroscopy for continuous analysis in an optofluidic device

The fabrication of substrates for surface-enhanced Raman spectroscopy (SERS), which offer high enhancement factors as well as spatially homogeneous distribution of the enhancement, plays an important role for expanding the surface-enhanced Raman spectroscopy to a powerful quantitative and non-invasive measurement technique. In this paper, a method for the fabrication of capable SERS-active substrates by laser treatment of gold films supported on glass with single 351?nm UV-laser pulses is presented. Resulting nanometer scaled structures show enhancement factors of up to 10⁶ with very high spatial reproducibility for a monolayer of benzenethiol. A method for integration of these substrates into PDMS microchannels is shown. A technique for the generation of a simple mold master for PDMS replication is presented. Rhodamine 6G is used as model system to demonstrate continuous measurements on a solid SERS-active substrate in a microchannel. The label-free detection of the biological molecule albumin is improved by an order of magnitude.     

A CMOS compatible process for monolithic integration of high-aspect-ratio bulk silicon microstructures

We report a CMOS compatible bulk micromachining method for the integration of high-aspect- ratio single crystal silicon MEMS （micro electromechanical systems） devices and signal conditioning circuit on a standard silicon wafer. The trench refilling and residual silicon removing techniques are used to acquire a proper electrical insulation between the different actuation and sensing elements situated on either fixed or movable parts of an MEMS device. To demonstrate the compatibility of the process, an integrated MEMS accelerometer was implemented. Test results show that the resistance between different elements of the device is larger than 1012 Ω. The electrical properties of the transistors that experienced MEMS fabrication agree well with those without ]VIEMS process, indicting the CMOS compatibility of the process.     

多壁碳纳米管-Nafion/纳米金构建阻抗传感器研究

利用多壁碳纳米管（ MWNT）—Nafion和纳米金（ GNPs）修饰金电极构建了一种简单、灵敏检测人端粒DNA的电化学阻抗传感器。首先将Nafion分散的MWNT滴涂于Au电极表面,再利用电化学沉积法将GNPs沉积到MWNT—Nafion修饰Au电极表面,以GNPs为载体固定人端粒探针DNA制备DNA传感器。在最优实验条件下,将传感器用于人端粒DNA的检测中,结果表明：目标人端粒DNA的线性范围为1.0×10－13～5.0×10－11mol/L,检出限（S/N＝3）为2.5×10－14mol/L。采用MWNT为基底沉积GNPs修饰电极检测的灵敏度显著提高。