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.     

半导体荧光纳米颗粒的制备及其在生物传感器中的应用

该文综述了半导体荧光纳米颗粒及核-壳结构半导体纳米颗粒的制备、性能表征及其在生物传感器上的应用研究情况,共引用文献54篇.     

聚乙烯亚胺修饰的银纳米颗粒的制备研究及在肝素检测中的应用

该文利用分子量为600的高支化聚胺高分子PEI,在室温条件下,采用化学还原法,使用还原剂硼氢化钠,合成了银纳米颗粒。该方法具有操作简单、便捷、可重复性高等特点。对合成的颗粒进行了一系列的表征,包括紫外可见光谱的测量,动态光散射测量和透射电镜表征等。并以该银纳米颗粒为基础,建立了比色法传感器用于肝素的快速检测,并获得了较好的检测结果,检测限为1μg／mL。该检测方法具选择性高、灵敏度好,且检测耗时短,便于人眼直接观测等优点。     

金纳米颗粒制备及其光学特性研究

采用晶种生长法通过改变晶种对生长溶液的体积比例、引入离子合成了棒状和星形金纳米颗粒.首先用NaBH4作为还原剂制得小粒径球形金纳米颗粒作为晶种溶液,生长溶液中引入AgNO3为辅助试剂、溴化十六烷三甲基铵(CTAB)为表面活性剂来引导合成形貌不同的颗粒.对制备的球状、棒状和星状金纳米颗粒进行了紫外-可见光谱测试和表面增强...     

氮化硼纳米片/ 银纳米杂化颗粒填充的环氧树脂复合材料的制备及其性能研究

填充型高导热聚合物复合材料是目前解决电子器件散热问题的重要材料。基于此,该文通过 液相剥离和化学还原法制备了氮化硼纳米片/银纳米粒子(BNNSs/AgNPs)杂化粒子,并以此为填料制 备了 BNNSs/AgNPs/环氧树脂复合材料。前期研究工作证实通过 BNNSs/AgNPs 杂化粒子的填充,复合 材料的导热性能得到了有效提高。然而,复合材料其他方面的综合性能也相当重要。因此,通过热失 重、动态热机械性能以及介电性能测试对 BNNSs/AgNPs/环氧树脂复合体系的电学和力学性能进行考 察和分析。结果表明,杂化粒子的填充对复合材料热分解温度有所提高,复合物的介电常数随着填料 含量的增加而增加,BNNSs/AgNPs/环氧树脂的介电常数相对于 BNNSs/环氧树脂有进一步的提高。复 合材料的储能模量和玻璃化转变温度随着填料含量的增加而升高。相对于 BNNSs,BNNSs/AgNPs 杂 化粒子使得环氧树脂复合物的玻璃化转变温度进一步提高。BNNSs/AgNPs/环氧树脂复合材料良好的热 学、力学和电学性能,能进一步满足聚合物基复合材料在现代电子器件和设备封装领域的要求。     

功能化硅壳磁性纳米颗粒亲和吸附介质靶向分离蛋白质研究

基于溴化氰修饰方法在硅壳磁性纳米颗粒表面修饰功能性生物分子,获得功能化硅壳磁性纳米颗粒亲和吸附介质.以胰蛋白酶-胰蛋白酶抑制剂作为模式亲和对,基于酶和抑制剂之间的特异性结合原理,首先考察了胰蛋白酶抑制剂的修饰对硅壳磁性纳米颗粒粒径和电位的影响及其修饰效率,然后利用胰蛋白酶抑制剂修饰的硅壳磁性纳米颗粒亲和吸附介质对简单模型蛋白质混合溶液以及胰脏组织中的胰蛋白酶进行靶向分离.该研究基于硅壳磁性纳米颗粒的内核磁性及表面生物修饰,为蛋白质分离提供了一种新型亲和吸附介质.     

金纳米颗粒的绿色制备及其在生物传感器中的应用

由于金纳米颗粒（AuNPs）特殊的化学、物理特性。使其在生物催化及传感器领域有了越来越重要的应用。目前用来制备金纳米材料的方法有很多。近年来采用新型的、洁净无毒的、绿色的方法来合成金纳米粒子越来越受到重视。     

纳米颗粒增强尿酸酶生物传感器的研究设想

文章简要介绍了尿酸酶生物传感器研究的必要性及国内外研究现状;阐述了纳米颗粒增强酶生物传感器的初步机理,并对国内外纳米颗粒增强葡萄糖氧化酶生物传感器的研究进展进行评述.本课题组设想并正在进行有关纳米颗粒增强尿酸酶生物传感器方面的探索研究.     

基于微通道的ZnO纳米棒生物荧光检测研究

利用种子法和水热合成技术,分别在常规条件下和阵列式微通道中制备氧化锌(ZnO)纳米棒.采用扫描电子显微镜(SEM)、X射线衍射(XRD)等分析方法表征ZnO纳米棒的表面形貌特点和晶体结构.结果表明:微通道中制备的ZnO纳米棒的比表面积、结晶度和c轴取向性均有较大程度的提高.同时,建立了基于阵列式微通道的ZnO纳米棒生物荧光检测方法,利用ZnO纳米棒可显著增强荧光信号,对异硫氰酸荧光素标记的羊抗牛IgG抗体的检测限为1×10-4 μg/mL.     

基于纳米金、铁氰化镍纳米颗粒共修饰的电流型甲胎蛋白免疫传感器的研究

该文通过铁氰化镍纳米颗粒和纳米金之间的化学作用及强的吸附作用,利用纳米金良好的生物兼容性和强烈的吸附作用固定甲胎蛋白抗体,最后用牛血清白蛋白封闭非特异性吸附位点,从而制备了一种新型的用于检测甲胎蛋白的电流型免疫传感器.在优化条件下,该传感器分别在1.0到10.0ng/mL和10.0到200.0 ng/mL两个浓度范围内对甲胎蛋白展示了良好的线性响应关系,检出限为0.2 ng/mL.     

Extending donor size in D-A-π-A organic dye for dye sensitized solar cells: Anti-aggregation and improving electron injection

We have theoretically designed two D-A-π-A dyes 3 and 4 based on the efficient references 1 and 2 by introducing an extra electron donor unit (D2). Via calculating the electronic structures of isolated dyes, we obtain that dyes 3 and 4 possess stronger light-harvesting efficiency imparted by the fluorescence energy transfer of D2 part, maintain comparable lifetime of excited states, and shorten the electron injection time significantly with regard to 1 and 2. Meanwhile, dye 3 positively shifts the edge of virtual states of TiO₂ in a larger extent compared to its counterparts. Then after considering the alignment morphology of multiple dyes adsorbed on TiO₂ surface, we find that dyes 3 and 4 manifest the capability of anti-aggregation obviously, which is evidenced by the smaller quantity of intermolecular electronic coupling compared to that of dyes 1 and 2, definitively illustrating the prominent performance of novel dyes with the bulky D2 moiety. Finally, dye 3 is screened out as the potential candidate for future application.     

Preparation of Ag–Au nanoparticle and its application to glucose biosensor

In this paper, Ag–Au nanoparticles are produced in sodium-bis(2-ethylhexyl)-sulfosuccinate (AOT)–cyclohexane reverse micelle system. The properties of the obtained nanoparticles are characterized with transmission electron microscope (TEM) and UV–vis absorption spectrophotometer. Glucose biosensors have been formed with glucose oxidase (GOx) immobilized in Ag–Au sol. GOx are simply mixed with Ag–Au nanoparticles and crosslinked with a polyvinyl butyral (PVB) medium by glutaraldehyde. Then a platinum electrode is coated with the mixture. The effects of the various molar ratios of Ag–Au particles with respect to the current response and the stability of the GOx electrodes are studied. The experimental results indicate the current response of the enzyme electrode containing Ag–Au sol increase from 0.32 to 19 μA cm⁻² in the solution of 10 mM β-d-glucose. In our study, the stability of enzyme electrodes is also enhanced.     

Toward rational design of organic dye sensitized solar cells (DSSCs): An application to the TA-St-CA dye

A computer aided rational design has been performed on TA-St-CA dye sensitizer in order to improve the desirable properties for new organic dye sensitized solar cell (DSSC). A number of electron-donating (ED) and electron-withdrawing (EW) units based on Dewar's rules are substituted into the π-conjugated oligo-phenylenevinylene bridge of the reference TA-St-CA dye. The effects of these alternations on the molecular structures and the electron absorption spectra are calculated using time-dependant density functional theory (TDDFT). It is found that chemical modifications using electron donating (ED) substitutions exhibit advantages over the electron withdrawing (EW) substitutes to reduce the HOMO–LUMO energy gap as well as the electron distribution of the frontier orbitals of the new dyes. Dewar's rule is a useful guideline for rational design of new dye sensitizers with desired HOMO–LUMO gap. The impact on the optical spectra of new dyes are, however, less significant.     

Computational study of diketopyrrolopyrrole-based organic dyes for dye sensitized solar cell applications

Four diketopyrrolopyrrole (DPP)-based organic dyes utilizing the donor–π-acceptor motif were investigated by density functional theory (DFT) and time-dependent DFT (TDDFT) approaches. The four dyes were composed of different donor groups, i.e. indoline, carbazole, triphenylamine, and coumarin. We investigated the effects of the DPP unit and different donors on the spectra and electrochemical properties of the dyes, respectively. In comparison with the model dye which adopts a phenylene unit as the π-spacer, the DPP dyes all display remarkably enhanced spectral responses in the visible region of the solar spectrum. The key to this increase was the incorporation of electron-deficient DPP moieties to the molecular core, which significantly lowers LUMO levels and therefore reduces the band gap. The dye/(TiO₂)₄₆ anatase nanoparticle systems were also simulated to show the electronic structures at the interface. We studied some key properties including absorption spectra, light-harvesting efficiency, molecular orbital distributions, and injection time of electrons from the excited state of dye to the conduction band of TiO_2. The dye DPP-I with indoline moiety as the electron donor demonstrates desirable energetic, electronic, and spectroscopic parameters for dye sensitized solar cells (DSSCs) applications. Our theoretical study is expected to provide valuable insights into the molecular design of novel DPP-based organic dyes for the optimizations of DSSCs.     

证书撤销机制的分析与研究

数字证书是实现电子政务和电子商务中实体的信任及信任验证的关键元素.CA实际可能会根据不同的情况而导致证书的意外作废或撤销,那么应使要使用证书的用户尽可能获知最新的证书情况,这对于实现PKI系统的可信性至关重要.通过分析国内外通常采用的CRL和OCSP这两种基本的证书撤销、查询方法,总结了它们的优缺点以及在实际应用过程中遇到的难点.最后提出了相应的改进措施,使用户能及时获得最新的证书状况,为电子政务和电子商务提供更可靠的安全性.     

Highly efficient and stable white organic light emitting diode with triply doped structure

A triply doped white organic light emitting diode with red and blue dyes in the light emitting layer and a green dye in another layer is proposed. The device structure was CuPc(12 nm)/NPB(40 nm)/ADN:DCJTB(0.2%):TBPe(1%)(50 nm)/Alq:C545(0.5%)(12 nm)/LiF(4 nm)/Al. Here copper phthalocyanine (CuPc) is a buffer layer, N,N′-di(naphthalene-1-y1)-N,N′-dipheyl-benzidine (NPB) is a hole transporting layer, 9,10-di-(2-naphthyl) anthracene (ADN) is blue emitting layer, tris (8-quinolinolato)aluminium complex (Alq) is an electron transporting layer, 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidy1-9-enyl)-4H- pyran (DCJTB), 2,5,8,11-tetra-butylperylene (TBPe), Coumarin6 and deveriative (C545) are red, blue and green dyes, respectively. This device shows a luminance of 21200 cd/m² at driving current of 400 mA/cm² and 1026 cd/m² at 20 mA/cm². Its efficiency is 6 cd/A and 3.11 Lm/W. It also shows a higher operating stability: the half lifetime is 22,245 h at an initial luminance of 100 cd/m², while the driving voltage increased only 0.3 V.     

Highly responsive fluorescent sensing of explosives taggant with an organic nanofibril film

Efficient sensing of an explosives taggant, 2,3-dimethyl-2,3-dinitrobutane (DMNB), has been performed with an organic nanofibril film through monitoring the fluorescence quenching of the film upon exposure to the DMNB vapor. The nanofibril film was fabricated from an alkoxycarbonyl-substituted carbazole-cornered conjugate tetracycle molecule, namely ACTC, which possesses a planar, rigid molecular geometry that favors cofacial π–π stacking between the molecules, leading to the formation of nanofibril structures with extended one-dimensional molecular stacking. The nanofibril film thus fabricated demonstrated unprecedented efficiency in detecting DMNB vapor, likely due to the extended one-dimensional molecular packing and the highly porous structure thus formed within the film. The former facilitates the exciton migration along the long-axis of nanofiber, while the latter enhances the adsorption of DMNB vapor and the expedient diffusion of the analyte through the film. The enhanced adsorption and diffusion of DMNB molecules within the matrix of the film also accounts for the improved response time of the film in fluorescence quenching upon exposure to DMNB vapor.     

Enhanced charge generation in doped organic/organic p–n heterojunction for improving the performance of tandem organic light emitting diode

The doped organic/organic p–n heterojunctions have been applied as charge generation structure (CGS) in tandem organic light emitting diodes (TOLEDs). It is found that the field‐induced charge generation takes place more efficiently at the interface between Li₂CO₃ n‐doped bathocuproine (BCP:Li₂CO₃) and MoO₃ p‐doped 4,4′‐N ,N′‐dicarbazole‐biphenyl (CBP:MoO₃) than at the interface between BCP:Li₂CO₃ and MoO₃ p‐doped 4,4‐bis[N‐1‐naphthyl‐N‐phenylamino]biphenyl (NPB:MoO₃). It is because the process of electrons tunneling through the depletion zone from the highest occupied molecular orbit (HOMO) of CBP:MoO₃ to the lowest unoccupied molecular orbit (LUMO) of BCP:Li₂CO₃ is more efficient than that from the HOMO of NPB:MoO₃ to the LUMO of BCP:Li₂CO₃. Compared to the TOLED using the conventional CGS of 10‐nm BCP:Li₂CO₃/20‐nm NPB:MoO₃, the one using the CGS of 10‐nm BCP:Li₂CO₃/10‐nm CBP:MoO₃/10‐nm NPB:MoO₃ shows increased device performance. In addition, the interconnecting property of CGS of 10‐nm BCP:Li₂CO₃/x nm CBP:MoO₃/20 ? x nm NPB:MoO₃ shows a strong dependence on the thickness of CBP:MoO₃. We provide a new insight on optimizing Ohmic loss in the CGSs, useful for improving the performance of TOLEDs.     

Control mechanism of an organic self-regulating microfluidic system

The control mechanism and fluid dynamic properties of a previously developed organic pH regulation system are analyzed. The system regulates an output fluid stream to a pH of 6.7 with varying input flow rates. A pH sensitive hydrogel post acts as the feedback pH sensor and flow regulator. The control mechanism of the system is studied through numerical modeling of the regulator and the model is validated through experimentation. Analysis of the fluid dynamics at a T-channel junction, in which two buffer streams merge into one, is performed by solving the Navier-Stokes equation with commercial software. Various areas of a star-shaped orifice are occluded by a flexible membrane to throttle the rate that compensating buffer is fed back into the system. The relationship between orifice open area and volume of compensating buffer through the orifice was analyzed numerically. The axial and lateral visualization of the hydrogel post was obtained via optical microscopy. The model of the regulation system successfully predicts experimental results.     

Energy‐transfer dynamics of blue‐phosphorescent iridium and rhodium complexes doped in fluorescent molecules

Abstract— The temperature‐dependent photoluminescence features of polycarbonate thin films doped with blue‐phosphorescent molecules, either bis[(4,6‐difluorophenyl)‐pyridinato‐N,C^2′] (picolinate) iridium (Flrpic) or bis(2‐phenylpyridinato‐N,C^2′) (acetylacetonate) rhodium [(ppy)²Rh(acac)], which have an equivalent triplet energy of 2.64 eV, have been studied. The photoluminescence intensity of the Flrpic‐doped polycarbonate thin film did not show any dependence on temperature. On the other hand, as for the (ppy)²Rh(acac)‐doped polycarbonate thin film, decreasing photoluminescence intensity with increasing temperature (especially above 100K) was clearly visible. These results reflect that the internal heavy‐atom effect of (ppy)²Rh(acac) is weaker than that of Flrpic. Furthermore, the steady‐state and time‐resolved photoluminescence spectra of tris(8‐hydroxyquinoline) aluminum (Alq₃) thin films heavily doped with Flrpic or (ppy)²Rh(acac) (50 wt.%) at 8K was studied. It was found that the enhanced phosphorescence from Alq₃ is mainly due not to the external heavy‐atom effect by doping with the phosphorescent molecule but to the exothermic triplet energy transfer from the phosphorescent molecule to Alq₃.