以金纳米粒子为探针比色法检测顺铂

报道了一种以金纳米粒子表面等离子吸收带变化为基础, 通过DNA与cis-Pt相互作用来检测溶液中cis-Pt浓度的新型比色法.     

纳米探针芯片技术用于微量乙肝病毒DNA的检测

利用两组探针修饰的微粒:(1)表面标记有可与待测乙肝病毒(HBV) DNA另一端结合的纳米金探针1(信号探针)以及可与信号探针部分结合的纳米金探针2(检测探针);(2)表面标记有可与待测HBV DNA一端结合的磁珠探针(捕捉探针1).检测靶HBV DNA时,磁珠探针与信号探针在液相中可分别与HBV DNA靶序列一端结合最终形成三明治样结构.再以磁场将三明治样复合物从反应液中分离,以DTT溶液将信号探针从纳米金颗粒上洗脱.洗脱后的信号探针数量反映靶基因的多寡,信号探针一段与预先点样的基因芯片上的捕捉探针2结合,检测探针与信号探针另一段相结合,最后用银染液将检测探针显色从而得到靶目标DNA相对定量信息.结果表明,本检测方法的检测灵敏度达到10-15 mol/L水平.检测时间少于1.5 h,检测结果与HBV DNA水平呈现较好的线性关系且无假阳性结果;本方法有望用于乙肝病人血清中HBV DNA的快速筛测及其它微生物基因的检测.     

Preparation of Nanogapped Gold Nanoparticle Array for DNA Detection

A novel DNA detection technique using a gold nanoparticle array film electrode has been reported here. The gold nanoparticles molecularly linked with binder molecule (1,10‐decanedithiol) were separated 1.3 nm from each other, and the DNA conductivity change from single to double strand was measured by monitoring a voltage drop across the particles, between which a probe of a 12‐mer oligonucleotide was immobilized. In adding a complementary oligonucleotide on the nanoparticle film chip, an immediate decrease in the film resistance (ca. 1.4 Ω) due to a hybridization event occurred in a reproducible manner with this simple setup. In the paper, we have an interest in the primary sensing properties; effect of the film resistance on the sensor response, dependence of the resistance change on the DNA concentration, and the performance of the system for DNA detection including single nucleotide polymorphisms were described.     

A Surface Plasmon Resonance Sensor Platform Coupled with Gold Nanoparticle Probes for Unpurified Nucleic Acids Detection

In this work, a surface plasmon resonance sensor system was designed and implemented for determination of nucleic acids in unpurified samples. First, through blocking non-specific interaction sites on the sensor surface to reduce non-specific adsorption from unpurified sample matrix, it was determined that at the optimal BSA concentration of 100 µg/ml the non-specific interaction can be reduced by 50%, although improvement for direct detection of nucleic acids in unpurified sample is required. Second, bearing nonspecific adsorption onto gold films, nucleic acids adsorbed on sensor surface in unpurified sample matrix were detected through a secondary hybridization approach. Using DNA-lined AuNPs shows the new SPR sensor can be applied for the determination of target ssDNA with a detection range of 0.1–10 µM for targets in purified and 1–10 µM in unpurified samples, respectively. Results imply that the new SPR sensor system is promising for specific and convenient analysis of nucleic acids directly in unpurified samples. Development of the new SPR sensor technique can have applications in fast field diagnostics and monitoring.     

金纳米粒子与聚吡咯纳米管的复合及其SERS效应研究

通过柠檬酸盐与HAuCl4水溶液在微沸状态下反应制备的金纳米粒子因其特殊的表面与界面效应在光学、生物学和催化化学领域得到了广泛应用,而聚吡咯(PPy)具有环境稳定性好、电导率高且变化范围大、容易合成等优点,聚吡咯纳米管可用作导电材料、酶封装材料、抗静电材料,也可用于制备传感器、传动器、固体电解质电容器等。     

花菁染料负载的聚合物纳米材料用于次氯酸可视化检测的研究

次氯酸(HClO)作为强氧化剂被广泛应用于日常生活中,研究对HClO浓度的便捷监测方法具有重要意义。针对HClO的可视化探针存在水溶性较差和易被光漂白的问题,本工作利用次氯酸根(ClO-)可破坏花菁染料的共轭结构这一特性,设计合成了一种花菁染料Cy7负载的聚苯乙烯纳米球(PS-Cy7),并研究了其与次氯酸的响应行为。实验结果表明,PS-Cy7具有良好的单分散性,粒径约为78nm;相比于花菁染料Cy7,PS-Cy7具有更好的水溶性和光稳定性,并且对次氯酸具有专一性的响应,其最低检测限为0.22μmol/L,实现了对HClO的可视化检测,有望用于日常生活中的HClO监测。     

Surface-enhanced Raman Scattering from Molecules Adsorbed on Mixed Silver/Gold Nanoparticle Surfaces

Introduction Since the first discovery of Surface-Enhanced Raman Scattering(SERS) from pyridine molecules adsorbed at roughened silver electrodes in 1974 by Fleischmann et al.[1],the research of SERS has made tremendous progress in applications of it to various fields of science and technology[2-8].     

Phenylboronic Acid‐Gold Nanoparticles for Potentiometric Detection of Saccharides

We propose a concept for the analytical application of gold nanoparticles modified by mercaptophenylboronic acid as a receptor of saccharides in a potentiometric sensor based on a conducting polymer.     

TTFV molecular tweezers with phenylboronic acid and phenylboronate endgroups: modular synthesis and electrochemical responses to saccharides and fluoride ion

Tweezer-like molecular systems containing a redox-active tetrathiafulvalene vinylogue (TTFV) unit and two phenylboronate or phenylboronic acid endgroups were synthesized via the Cu-catalyzed alkyne azide coupling (i.e., click) reaction. The TTFV-phenylboronic acid derivative was found to show different differential pulse voltammetric (DPV) responses to various monosaccharides in aqueous DMSO at pH 7.41, suggesting potential use in electrochemical sensing of saccharides. Moreover, the TTFV-phenylboronate derivative exhibited strong binding to the fluoride ion, giving rise to sensitive electrochemical detection of the fluoride ion.     

基于金纳米粒子掩模的硅表面纳米结构加工

利用金溶胶纳米粒子为掩模,结合轻敲模式原子力显微镜（TM AFM）的局域氧化技术和化学湿法腐蚀,对Si表面进行纳米尺度的结构加工,得到柱状和环状纳米结构.实验结果表明,氧化过程中AFM针尖与样品平均间距的大小显著影响后续纳米结构的形状.保持一定的氧化偏压、扫描速度和相对湿度,当针尖与样品间距为7.5 nm时,可得到柱状纳米结构;而当间距减小到5 nm时,则得到带芯环状纳米结构.不同几何形状的纳米结构形成的原因是体系中纳米粒子物理屏蔽效应.     

Colorimetric detection of glucose using a boronic acid derivative receptor attached to unmodifed AuNPs简

A simple, cheap and non-enzymatic colorimetric strategy for glucose detection has been designed based on the interactions between a phenylboronic acid （PBA） derivative, which is coupled with gold nanoparticles （AuNPs） as the colorimetric reporters, and glucose. The PBA-AuNPs hybrid system proposed here exhibits ordered photochemistry behaviors upon the addition of glucose at different pH values. There are two linear regions of glucose concentration for the glucose sensor at different pH values, i.e., between 0.1 mmol/L and 9.8 mmol/L at pH 6 with the detection limit of 64μmol/L and between 0 and 6.5 mmol/L with the detection limit of 48 μmol/L at pH 9, respectively. To test the practicality of the sensor system, we also applied this assay to detect a glucose sample in the artificial saliva.     

金纳米微粒作探针共振瑞利散射光谱法测定亚甲蓝

在pH为6.5~9.5的中性或弱碱性介质中, 金纳米微粒可与亚甲蓝(MB)阳离子靠静电引力及疏水作用力结合, 形成粒径较大的聚集体(平均粒径从12 nm增至20 nm), 这种聚集体的形成导致共振瑞利散射(RRS)强度显著增强, 最大散射峰位于371 nm. 在适当条件下, 散射强度(ΔI)与亚甲蓝浓度成正比. 该法具有高灵敏度, 将金纳米微粒作为测定亚甲蓝的高灵敏RRS探针, 对亚甲蓝的检出限为21.17 ng/mL, 该法简便, 快速, 且有较好的选择性, 可用于血液中亚甲蓝的测定.     

纳米金对荧光素的荧光增效作用

纳米金对荧光素的荧光效率具有增强作用,其增强效果取决于纳米金的尺寸大小和浓度。粒径分别为5、15、25 nm的纳米金与不同浓度的荧光素溶液作用后可以增强荧光强度3~10倍,同时讨论了溶液环境和pH值对荧光增强的影响。采用本实验提出的方法可以在生化检测方面提高荧光检测方法的灵敏度。     

纳米金探针检测Hg2+离子

利用Hg2＋的核酸适体修饰纳米金形成探针建立了一种定量检测Hg2＋离子的方法. Hg2＋适体吸附在纳米金表面, 使纳米金的稳定性增强, 抑制氯化钠对纳米金的团聚作用. 溶液中有Hg2＋离子存在时, 由于适体与纳米金的吸附作用小于适体与Hg2＋离子的亲和作用, 纳米金失去适体保护在氯化钠作用下发生团聚. 溶液颜色由红变蓝, 紫外-可见光谱最大吸收峰由520 nm红移至620 nm. 在优化条件下, 吸光度的比值(A620/A520)与Hg2＋离子浓度在5.0×10－9～7.2×10－7 mol•L－1范围内呈线性关系, 检测限可达3.3×10－10 mol•L－1. 研究了K＋, Ca2＋等常见离子的干扰, 结果表明该方法具有良好的选择性.     

铁纳米粒子共振光散射测定纳克级核酸

核酸作为生物遗传的物质基础,对其进行分析化学研究一直备受关注.当前,微流控分析技术的快速发展为核酸的高灵敏检测展示了新的前景.     

Dispersion of Nanoparticle Clusters by Ball Milling

The full and complete dispersion of nanoparticles is critical to enabling industry to formulate products which exploit the properties of such materials and hence realize the full economic value of such products.

Ball milling is conventionally used for the comminution of particle slurries and, of the various wet milling techniques, is the most effective in producing fine particle sizes. Here we consider the use of a ball mill (also referred to as a stirred media mill) for the dispersion of a slurry of nanoparticle aggregates and compare its performance to a typical rotor‐stator device commonly used by industry. The slurry is an aqueous dispersion of Aerosil 200 V that has a primary particle size of about 12 nm and comes as a dry powder. On dispersion in water it forms large aggregates which are difficult to fully disperse. Aerosil is readily available in quantity and is used in a number of industrially relevant applications and so is an ideal test material for such trials.

A lab scale Fryma Co‐Ball mill (0.5 L volume) is used and the effects of bead fill (40–70%), flow rate (0.1–1 kg/min) and rotor speed (7.5–18 m/s) are investigated. Specific energy is the most effective ways to correlate performance to particle size suggesting that residence time (i.e., flow rate) is the most important process parameter. Lower rotor speeds are also shown to be more energy efficient. The correlations show that the ball mill provides a significant improvement in dispersion (d[3,2]=0.61 µm) over the conventional rotor–stator device.     

基于胸腺嘧啶-汞离子-胸腺嘧啶结构和纳米金放大传感器检测汞离子

利用Hg2+与DNA中胸腺嘧啶(T)结合的高度特异性和纳米金在石英晶体微天平(QCM)上的信号放大作用,设计了一种简便灵敏的Hg2+检测方法.纳米金采用柠檬酸钠还原法制备,其表面用末端带巯基的寡核苷酸探针进行自组装修饰,并用6-巯基己-1-醇(MCH)部分取代表面探针,以减少杂交空间位阻.结果表明,寡核苷酸链长为9bp、T个数为7的序列具有较高灵敏度;线性范围为5.0～100 nmol/L;检出限为2.0 nmol/L;Ca2+、Mg2+等其它金属离子无明显干扰.用于环境水样中Hg2+的测定, RSD<2.9%;加标回收率为97.3%～101.2%     

DNA功能化纳米金用于生物小分子检测

纳米金是金的微小颗粒,在水溶液中以胶体金的形态存在。胶体金的颜色会随着其粒径及表面修饰差异而发生变化,这种颜色变化可通过肉眼观察;同时,这种改变会产生强烈的光散射或光吸收信号。基于这种信号而建立的纳米金比色检测法,已被广泛用于生物分子(如核酸、蛋白质、多糖甚至是细胞)的检测。DNA功能化纳米生物传感器是利用核酸碱基配对原则进行识别,能实现特定基因片段的持续、快速、灵敏和选择性检测。本文结合最近十年的研究现状,主要论述了DNA功能化纳米金用于比色检测法的原理及用于核酸、蛋白质和部分生物小分子的检测,并评述了其中的挑战和前景。     

微接触印刷技术在ITO基底上快速转移Au纳米粒子图案

采用无氰化学镀金法在聚二甲基硅氧烷(PDMS)印章表面镀金, 通过微接触印刷技术将PDMS印章上的Au 纳米粒子(AuNPs)分别转移到氧化铟锡(ITO)透明导电膜玻璃, 修饰了(3-巯基丙基)三甲氧基硅烷(MPTMS)的ITO基底(MPTMS/ITO)和表面电镀了铜膜的ITO(Cu/ITO)表面上, 同时形成有序的结构或者图案.通过场发射扫描电镜(FE-SEM), 原子力显微镜(AFM)和显微共聚焦激光拉曼光谱仪等对实验结果进行表征.结果表明, 该转移AuNPs的方法对基底表面特性并无特殊要求, 是一种简单、快速、无污染、低成本的AuNPs转移技术, 而且转移了AuNPs的ITO基底具有表面增强拉曼光谱(SERS)活性, 有望在SERS中有所应用.     

Determination of DNA Hybridization on Gold Nanoparticle Conjugated Polystyrene Particle Thin Film Using Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy

Attenuated total reflectance Fourier transform infrared spectroscopy was used to detect DNA hybridization on a polystyrene conjugated gold nanoparticle thin film. The gold nanoparticles were synthesized on the surface of poly(ethylenimine) coated polystyrene particles by citrate reduction. Single-stranded DNA was then immobilized on the nanoparticle surface via thiol bonding. Ultraviolet-visible spectrometry was used to monitor the conjugation of the nanoparticles on polystyrene particles and the immobilization of a single-stranded DNA probe. The morphology of the polystyrene-gold nanoparticle thin film was characterized using scanning electron microscopy and showed successful conjugation and immobilization. The infrared spectra obtained from the hybridization showed features of DNA structure and peak shifts at 1657 cm^?1 compared to the non-complementary DNA due to changes in hydrogen bonding between N-H and C?O of complimentary bases pairs. The peaks at 1067, 975, 920, and 859 cm^?1, which were shifted to lower wavenumbers in the polystyrene-gold nanoparticle probe and target DNA, indicated hydrogen bonding formation between N-H and N of complimentary base pairs. ATR-FTIR spectroscopy provided simple, fast, and portable label-free detection of target DNA sequence on the polystyrene-gold nanoparticle thin film.