16 research outputs found

    Shell-isolated Nanoparticles-enhanced Raman Spectroscopy and Its Application in Single-crystal Electrochemistry

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    表面增强拉曼光谱(SERS)具有指纹识别、灵敏度高、检测限低甚至能达到单分子检测水平等的优点。因此,自SERS技术发现以来,已被广泛地应用在生物科学、环境科学等方面。然而其材料普适性和形貌普适性差的缺点,使得SERS技术不能应用在光滑的表面,如模型体系-单晶界面。因此,在2010年,我们课题组研发了壳层隔绝纳米粒子(SHINERS)技术,即在具有强SERS活性的金纳米粒子表面包裹上一层薄且无针孔的二氧化硅壳层。内核的金纳米粒子相当于是信号放大器,可以放大表面物质的拉曼信号,同时外层的二氧化硅壳层可以隔绝纳米粒子直接与外界环境相接触,使得纳米粒子不受外界环境的影响。 本论文采用了电化学和SHI...SERS has gained great attention in the field of bioscience and environmental sciences due to its sensitivity and molecular specificity. However, there are still two main limitations regarding the applications of SERS, lacking of material generality and morphology generality, which makes SERS cannot be applied on a smooth surface, such as single crystal electrode surface. In 2010, our group invente...学位:理学硕士院系专业:化学化工学院_分析化学学号:2052014115153

    Dual Fluorescence from Aqueous 1-Naphthylamine Solutions of High pH ——Excited-State Acidic Dissociation of Naphthylamine

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    Dual fluorescence at ca. 447 nm and 545 nm w as observed from the aqueous 12naph thylam ine (NA ) solutions at pH h igher than 1316. Sim ilar dual fluorescence was also found w ith sodium12naph thylam inoacetate (NAA ) , but not w ith N , N 2disubstituted 12am inonaph thalenes such as sodium 12 naph thylam inodiacetate (NADA ) and 12dimethylam inonaph thalene (DMAN ). No change in absorption spectra of NA and NAA w as observed in th is pH region. It w as p roposed that the dual fluorescence ob2 served w ith NA and NAA w as due to the excited state dissociation of the p rimary and secondary am ines at h igh pH. F rom the dual fluorescence intensity ratio pH titration curve, the pK 3 ’ a s of NA and NAA w ere estimated to be betw een 14 and 15 w h ich aremuch low er than the ground state pK a. The novel app roatch is such a simp le, convenient and frequent analysis technique that it can bew idely used in detecting the sub2stitutional derivatives of am inonaph thalene.教育部优秀年轻教师基金(批准号 :教人司 2 0 0 0 -11);国家自然科学基金(批准号 :29975023)

    Thiourea-based Receptors for Anion Recognition and Sensing

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    [中文文摘]阴离子识别是超分子化学研究的重要内容之一 ,其关键环节是构筑可识别阴离子的结合受体 ,后者以非共价键力如静电作用、疏水作用、氢键等与阴离子结合。本文详细评述了近 5年来硫脲类阴离子识别受体的设计、结构及其阴离子识别作用的研究进展。[英文文摘] Anion recognition and sensing have been developed into an important research subject in supramolecular chemistry. Noncovalent interactions such as hydrogen bonding , electrostatic interaction , hydrophobic interaction , etc.are the most important binding forces existing in the anion2receptor binding complexes , which forms the basis of designing anion binding receptors. The design , construction and anion recognition and sensing of thiourea2based receptors following mainly multi hydrogen bonding interactions are reviewed. 51 key references were cited to represent the related advances in the past 5 years.国家自然科学基金 (2 0 1 75 0 2 0 );福建省自然科学基金 (D0 2 2 0 0 0 1 )项目

    便携式拉曼光谱仪快速检测唾液中盐酸吡格列酮的含量

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    人体唾液与血液中的相应成分有着密切关系。利用唾液代替血液进行检测,可极大地缩短分析时间、减少检测限制、降低安全隐患等,因此在临床医学、毒品管控等方面均有重要意义。发展了便携式拉曼光谱仪利用表面增强拉曼光谱技术快速定量检测唾液中盐酸吡格列酮(口服降血糖药物)含量的方法。借助纳米金溶胶的表面增强拉曼散射效应,在激发光源波长为785 nm时,可以得到低浓度盐酸吡格列酮的高质量拉曼光谱图。同时,不同浓度盐酸吡格列酮表面增强拉曼光谱分析结果表明,该方法还可直接用于唾液中盐酸吡格列酮的定量检测。盐酸吡格列酮含量与其特征峰强度线性相关,相关系数为0. 992 3,且最低检测浓度达10μg·L-1。国家自然科学基金项目(21522508);;深圳市科技计划基础研究(自由探索)项目(JCYJ20170306140934218)资

    Dual fluorescence from aqueous 1-naphthylamine solutions of high pH - Excited-state acidic dissociation of naphthylamine

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    Dual fluorescence at ca. 447 nm and 545 nm was observed from the aqueous 1-naphthylamine (NA) solutions at pH higher than 13.6. Similar dual fluorescence was also found with sodium 1-naphthylaminoacetate(NAA), but not with N, N-disubstituted 1-aminonaphthalenes such as sodium 1-naphthylaminodiacetate (NADA) and 1-dimethylaminonaphthalene (DMAN). No change in absorption spectra of NA and NAA was observed in this pH region. It was proposed that the dual fluorescence observed with NA and NAA was due to the excited state dissociation of the primary and secondary amines at high pH. From the dual fluorescence intensity ratio pH titration curve, the pK(a)(.)'s of NA and NAA were estimated to be between 14 and 15 which are much lower than the ground state pK(a). The novel approach is such a simple, convenient and frequent analysis technique that it can be widely used in detecting the substitutional derivatives of aminonaphthalene

    Rapid determination of 1,2-propylene glycol and glycerol in refill fluids for electronic cigarettes by Raman spectroscopy

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    为实现电子烟烟液主要成分的简便快速检测,建立了同时测定电子烟烟液中1,2-丙二醇和丙三醇含量的拉曼光谱分析方法,利用该方法测定了17个电子烟烟液; 样品,并与气质联用法进行了结果比较。结果表明:①1,2-丙二醇和丙三醇分别在0.125~0.956和0.106~1.120; g/mL时,以522和671 cm~(-1)特征信号峰强度绘制的标准工作曲线线性关系良好(R~2>; 0.999),单样本和独立样本t检验结果证实方法的准确性较高。②17个电子烟烟液样品中,1,2-丙二醇和丙三醇的含量分别为0.533~0.766; 和0.182~0.476; g/mL。该方法与气质联用法检测结果的配对样本t检验结果表明,在95%置信概率下,两种方法的定量结果一致。该方法不需进行样品前处理,更适用于批量; 电子烟烟液中1,2-丙二醇和丙三醇的快速定量分析。A simple and rapid Raman spectroscopy method for simultaneous; determination of 1,2-propylene glycol and glycerol in refill fluids for; electronic cigarettes was developed. Samples of 17 refill fluids were; analyzed by a portable Raman spectrometer,and the data were compared; with those determined by GC-MS. The results showed that: 1) The standard; curves of 1,2-propylene glycol and glycerol determined at the Raman; intensity of 522 and 671 cm~(-1) possessed good correlation coefficients; (R~2 above 0.999) in the content range of 0.125-0.956 and 0.106-1.120; g/mL,respectively. The results of one sample t-test and independent; sample t-test indicated that the Raman method was accurate. 2) The; contents of 1,2-propylene glycol and glycerol in 17 refill fluids were; in the range of 0.533-0.766 and 0.182-0.476 g/mL, respectively. The; result of paired sample t-test showed that the data determined by Raman; spectroscopy were consistent with those obtained by GC-MS at a; confidence level of 95%. Without sample pretreatment, Raman spectroscopy; method is simple to operate and more suitable for the rapid quantitative; determination of 1,2-propylene glycol and glycerol in batches of refill; fluids for electronic cigarettes.浙江中烟工业有限责任公司科技项

    Thiourea-based receptors for an on recognition and sensing

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    Anion recognition and sensing have been developed into an important research subject in supramolecular chemistry. Noncovalent interactions such as hydrogen bonding, electrostatic interaction, hydrophobic interaction, etc. are the most important binding forces existing in the anion-receptor binding complexes, which forms the basis of designing anion binding receptors. The design, construction and anion recognition and sensing of thiourea-based receptors following mainly multi hydrogen bonding interactions are reviewed. 51 key references were cited to represent the related advances in the past 5 years

    便携式拉曼光谱仪快速检测废水中残留有机溶剂

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    本文通过使用便携式拉曼光谱仪来快速检测废水中残留有机溶剂的种类和含量。首先利用便携式拉曼光谱仪建立标准拉曼谱图库,然后用便携式拉曼光谱仪检测废水样品并与标准谱图库比对,即可获得废水中含有的有机溶剂的种类和含量。该方法简便、灵敏、快速,对于实时监测废水的排放具有重要意义。国家自然科学基金(21522508);;浙江省重点研发计划(2017C03002,2018C03077

    利用表面增强拉曼光谱快速鉴别卷烟生产中烟用香精香料

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    烟用香精香料的配方是卷烟工业中的核心技术,也是构建不同特色卷烟产品的关键之一。然而,现有的香精香料质量评价手段主要是人工嗅香和测定某些特定的物性指标,如折光指数、相对密度、酸值、挥发份总量等。在实验室科研中还有使用色谱-质谱联用等方法。但是上述手段仍存在较多问题,比如受主观意识影响,操作繁琐,前处理耗时长,费用高,灵敏度低等。基于此,本文开发了一种利用表面增强拉曼光谱技术结合主成分分析算法来快速鉴别实际生产中不同种类、不同掺兑样的烟用香精香料的方法。本文利用该方法成功获取不同种类、同一种类不同生产批次及烟用香精香料不同掺兑量样品的增强拉曼谱图。经主成分分析表明不同种类以及不同掺兑量样品的散点分布在不同区域,直接区分度高;同一种类不同生产批次的香精香料谱图类似,在散点图中较为集中;说明不同生产批次的样品以及不同掺兑量的样品都可以与其他种类的香精香料标准样品进行有效区分。本文利用表面增强拉曼光谱结合主成分分析算法对烟用香精香料进行检测的方法操作简易,检测快捷,成本低廉,结果便于分析识别,适用于烟用香精香料实际生产中的质量控制。国家自然科学基金(No.21522508)浙江中烟工业有限责任公司科技项目(No.ZJZY2016C002

    Observation of inhomogeneous plasmonic field distribution in a nanocavity

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    等离激元材料和器件中电场的强度分布是等离激元技术及其应用的重要基础。虽然针尖增强光谱成像技术的发展已经实现了亚纳米的横向空间分辨率,并发现了亚纳米级电场的不均匀性,但是迄今人们对电场的纵向场强分布仍然知之甚少。李剑锋教授课题组设计了一种具有~2Å空间分辨率的分子尺,利用金单晶基底和壳层隔绝金纳米粒子来构筑等离激元纳米腔,并通过分子尺的拉曼信号强度,精准地直接表征纳米腔中的纵轴方向上高度不均匀的场强分布。中国科学技术大学罗毅教授课题组利用基于量子场论的局域场光谱理论,精确地模拟得到了与实验相符的等离激元纳腔中的场分布,并发现了因分子自聚焦作用而引起的“等离激元梳”。该工作提供了一种通用有效的定量表征纳腔中场强分布的方法,完善了对等离激元学基础的理解,为超高空间分辨的拉曼光谱成像、光学力调控分子组装、单分子反应操控提供指导。 该工作是在李剑锋教授和中国科学技术大学罗毅教授共同指导下完成的。实验部分主要由李超禹(论文第一作者,已毕业博士)、温宝英(在读博士)、李松波(已毕业硕士)完成,复旦大学段赛研究员(论文共同第一作者)和陈舒(已毕业博士)进行了局域场光谱理论计算。谢立强(已毕业博士)和毛秉伟教授帮助完成了扫描探针显微镜实验。浙江师范大学周小顺教授和王亚浩老师提供了自组装膜表征方面的重要帮助。印度的Kathiresan、叶龙武教授课题组和浙江大学陆展教授课题组在分子合成方面提供了重要帮助。瑞士伯尔尼大学Wandlowski教授和田中群教授为该工作提供了指导。【Abstract】The progress of plasmon-based technologies relies on an understanding of the properties of the enhanced electromagnetic fields generated by the coupling nanostrucutres.Plasmon-enhanced applications include advanced spectroscopies, optomechanics, optomagnetics and biosensing. However, precise determination of plasmon field intensity distribution within a nanogap remains challenging. Here, we demonstrate a molecular ruler made from a set of viologen-based, self-assembly monolayers with which we precisely measures field distribution within a plasmon nanocavity with ~2-Å spatial resolution. We observed an unusually large plasmon field intensity inhomogeneity that we attribute to the formation of a plasmonic comb in the nanocavity. As a consequence, we posit that the generally adopted continuous media approximation for molecular monolayers should be used carefully.The progress of plasmon-based technologies relies on an understanding of the properties of the enhanced electromagnetic fields generated by the coupling nanostrucutres1,2,3,4,5,6. Plasmon-enhanced applications include advanced spectroscopies7,8,9,10, optomechanics11, optomagnetics12 and biosensing13,14,15,16,17. However, precise determination of plasmon field intensity distribution within a nanogap remains challenging. Here, we demonstrate a molecular ruler made from a set of viologen-based, self-assembly monolayers with which we precisely measures field distribution within a plasmon nanocavity with ~2-Å spatial resolution. We observed an unusually large plasmon field intensity inhomogeneity that we attribute to the formation of a plasmonic comb in the nanocavity. As a consequence, we posit that the generally adopted continuous media approximation for molecular monolayers should be used carefully.The Swedish National Infrastructure for Computing is acknowledged for computer time. S.D. is sponsored by Shanghai Pujiang Programme (grant no. 19PJ1400600). 该研究工作得到国家自然科学基金、国家重点研发计划、安徽省量子信息技术引导专项等的资助和支持
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