基于液芯波导原理的微流控芯片长光程光度检测系统

提出了一种基于液芯波导(Liquidcorewaveguide,LCW)原理的微流控芯片吸收光度检测系统.通过芯片与外界接口技术实现液芯波导管与芯片的耦合,建立了芯片上长光程(毫米至厘米级)吸收光度检测池.采用邻菲啉-铁(Ⅱ)显色体系验证系统分析性能,以5.5cm外覆TeflonAF液芯波导管作为检测池(检测池体积240nL)时,芯片系统的检测线性范围为0.03～50μmol/L,对邻菲啉-铁(Ⅱ)配合物的检出限为8nmol/L,检测池有效光程达1.7cm,分析精度RSD(n=5)为0.8%.     

顶空毛细管气相色谱法测定水中碘化物

在酸性条件下水中的碘化物可被重铬酸钾氧化成I2，I2与丁酮反应又生成3-碘-2-丁酮。本文根据3-碘-2-丁酮易挥发的特性，采用顶空进样技术，结合毛细管气相色谱法(CGC)分离-微池电子捕获检测器(μ-ECD)检测，建立了一种测定水中碘化物的方法。该方法操作简捷，检测限低，线性范围宽，结果令人满意。     

多材料3D打印技术制作用于毛细管电泳的非接触电导/激光诱导荧光二合一检测池

利用多材料3D打印技术研制了用于毛细管电泳(CE)的二合一检测池,实现了电容耦合非接触电导(C⁴D)与共聚焦激光诱导荧光(LIF)两种检测方法在毛细管柱上同一位置同时检测。3D打印的检测池采用了导电的复合聚乳酸(PLA)材料制作C⁴D的屏蔽层,采用普通的绝缘PLA材料支撑C⁴D金属管电极并隔离屏蔽层。两根金属管电极通过“打印-暂停-打印”的方式嵌入到检测池中,两电极被2 mm厚的导电屏蔽层隔开,在屏蔽层中有一直径为1 mm的圆形通孔用于LIF检测。该检测池与带流通式进样接口的自组装CE系统联用,用于同时检测无机离子和异硫氰酸荧光素(FITC)标记的氨基酸。研究优化了C⁴D激励信号频率与电泳缓冲液浓度,选用的电泳缓冲溶液为10 mmol/L 3-吗啉丙烷-1-磺酸(MOPS)与10 mmol/L二(2-羟乙基)亚氨基三(羟甲基)甲烷(Bis-Tris)的混合溶液,选用C⁴D激励频率为77 kHz。二合一检测池应用于内径为25 μm的毛细管时,C ⁴D对Na⁺、K⁺和Li⁺的检出限分别为2.2、2.0和2.6 μmol/L; LIF对荧光素和FITC的检出限分别为7.6和1.7 nmol/L。两种检测方法的相对标准偏差在0.3%至4.5%之间(n=3),工作曲线的相关系数r ²≥0.9904。采用3D打印技术可以在实验室内实现复杂结构的制作,降低了制作的成本,且便于方法的推广和改进。     

基于氧化石墨烯信号放大的化学发光法联合检测甲胎蛋白和癌胚抗原

提出了一种基于信号放大技术的流动注射化学发光免疫传感器, 用于联合检测人血清中甲胎蛋白(AFP)和癌胚抗原(CEA)的含量. 该传感器首先用表面接枝羧基的氧化石墨烯来吸附固定辣根过氧化物酶(HRP)标记的二抗, 制得信号放大型免疫探针. 然后用合成的磁性介孔材料Fe₃O₄/SiO₂来吸附固定AFP和CEA的单克隆抗体, 用磁铁将其吸附在两个检测池内壁. 当待检样品和信号放大型免疫探针陆续注射进入相应检测池, 发生夹心式免疫反应, 形成的免疫复合物被磁条吸附在检测池内壁. 随后加入鲁米诺和H₂O₂发光底物, 与酶标记物发生酶促增强的化学发光反应, 并通过控制设在两个管路上的开关来控制鲁米诺和H₂O₂的流通, 相继检测两个检测池中的化学发光信号, 从而实现两种待测物的同时检测.     

即抛型氧化石墨烯/血红蛋白传感器的制备及其对H_2O_2的测定

采用丝网印刷技术制备传感器(SPE),将制备好的氧化石墨烯(GO)修饰于SPE表面用以固载血红蛋白(Hb),构建氧化石墨烯/血红蛋白修饰传感器(Hb/GO/SPE)。Hb/GO/SPE配合实验室自制反应池,实现了对H_2O_2的电化学检测。结果表明,制备的GO具有良好的导电性和生物相容性,促进了Hb的直接电子转移,对H_2O_2的还原具有良好的电催化活性。Hb/GO/SPE对H_2O_2在6.0×10~(-6)～2.0×10~(-2) mol/L的浓度范围内表现出良好的线性关系,线性相关系数R=0.997,检测限(S/N=3)为3.5×10~(-6) mol/L。Hb/GO/SPE测定步骤简单、检测范围宽、稳定性和重现性较好,测定完成后Hb/GO/SPE即可抛弃,使用方便快捷。     

一种以发光二极管为激发光源的荧光检测器

利用高亮度发光二极管作为激发光源组装了一荧光检测器并应用于毛细管电泳检测 ;激发光斑与毛细管检测池的耦合通过透镜加光阑组合方式实现 ;光纤用于收集并传输荧光信号 ,增加了光学系统的灵活性和紧凑性 ;光阑、检测池和光纤之间的校准简单、方便 ;用荧光素和异硫氰酸荧光素衍生的氨基酸考察了体系性能 ,最小检测浓度为0.18μmol/L(S/N=5) ,在2×10-7～4×10-5 mol/L范围内表现出较好的线性关系(r=0.993) ,结果表明该系统灵敏度达到了普通荧光检测器的指标     

伯胺N1923萃取钯(II)的动力学研究

报导了用恒界面池搅拌考察N1923-正辛烷溶液从氯化物介质中萃取Pd(II)时诸因素的影响.并用离子选择电极连续检测萃取过程中水相Pd(II)浓度随时间的变化.     

分光光度计改装为用于高压液相的检测器

高速液相色谱仪常配有单波长紫外检测器,检测灵敏度最高可达2×10~(-5)-5×10~(-5)吸光度,但缺点是有些试样在254毫微米处没有吸收或吸收很小。紫外分光检测器则可以按照被测试样的吸收情况任意选择检测波长以提高检测灵敏度,因此为国外商品仪器所普遍采用。这种检测器,实际上就是一种简易的分光光度计,但与一般分光光度计不同的是它必须具有以下特点: 1.必须配有容积较小的流动型样品池,一     

平行入射式光谱电化学池的制作及分析应用

本工作制作了用于定量分析的平行入射式光谱电化学池,电极长度为2 cm,光束高度约为120μm。稳定的吸光度在较宽的浓度范围内具有良好的线性关系,最低检测限对氢醌为3×10~(-8)mol/L,而对邻甲联苯胺为2×10~(-8)mol/L。利用光谱电化学可以在四倍的多巴胺存在下测定抗坏血酸,而大量存在的抗坏血酸对多巴胺的测定无影响。     

微流控芯片化学发光检测系统的设计及其应用

通过标准光刻、化学刻蚀及热键合技术制作微流控电泳芯片,在芯片上集成流通式化学发光检测池,实现样品的芯片电泳分离化学发光检测.采用双(2,4,6-三氯苯基)草酸酯(TCPO)-过氧化氢化学发光体系,通过微泵输送化学发光试剂.单酰化苯并氨基酸和单酰化肌氨酸在该系统中得以成功地分离检测,其检测限分别达到2.8和3.2μmol/L.     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.     

Synthesis of N-substituted carbazolones from α-iodo enaminones via Pd(0)-catalyzed intramolecular coupling under microwave irradiation

A variety of N-aryl and N-alkyl carbazolones were conveniently achieved in good to high yields via Pd₂(dba)₃-mediated intramolecular coupling of N-substituted α-iodo enaminones under microwave irradiation. The Pd(0)-catalyzed cyclization was found to proceed favorably with the more electron-deficient phenyl ring during the reactions involving unsymmetrical N,N-diaryl α-iodo enaminones. This unique property enables the construction of carbazolone skeleton containing nitro substituted benzenoid ring.     

Synthesis of substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles by intramolecular nitrilimine cycloaddition

Both substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles have been synthesized by the 3+2 intramolecular dipolar cycloaddition of nitrilimines to alkynes. This cyclization has been extended to more versatile 3-bromo derivatives by the use of alkynylbromides as dipolarophiles.     

Catalyst free,visible-light promoted photoaddition reactions between C60 and N-trimethylsilylmethyl-substituted tertiary amines for synthesis of aminomethyl-1,2-dihydrofullerenes

An efficient and benign method for the preparation of aminomethyl-substituted fullerenes has been developed. The process, involving catalyst free, visible-light irradiation of 10% EtOH-toluene solutions containing fullerene C₆₀ and N-trimethylsilylmethyl-substituted amines by using a 20 W compact fluorescent lamp, leads to formation of aminomethyl-substituted fullerene adducts in a highly efficient manner. The photoaddition reaction takes place via a pathway initiated by visible light absorption by C₆₀, followed by SET from the amine to the triplet excited state of C₆₀. Ethanol-promoted desilylation of the resulting a minimum radical then generates the corresponding α-amino radical which couples with the C₆₀ radical anion to form the anion precursor of the fullerene adducts. The new approach using visible-light takes place under mild conditions and it does not require the use of photocatalysts. Thus, the method developed in this effort could broadens the range of functionalized fullerene derivatives that can be readily prepared.     

Highly efficient and stereoselective cycloaddition of nitrones to indolyl- and pyrrolylacrylates

The reactions of various nitrones with indolyl- and pyrrolylacrylates proceeds regioselectively with high diastereoselectivity in the case of aldonitrones, and represents an effective method for obtaining new indolyl- and pyrrolyl-substituted isoxazolidine carboxylates stabilized by weak (CH?O) and moderate (NH?N) strength intramolecular hydrogen bonding. The resulting cycloadducts exhibit promising in vitro anti-influenza activities.     

Transition metal-free direct amination of benzoxazoles using formamides as nitrogen sources

A transition metal-free method for the direct amination of benzoxazoles using formamides as nitrogen sources is reported, which was mediated by an inexpensive and environmentally friendly tetrabutylammonium iodide/tert-butyl hydroperoxide system and gave the 2-aminobenzoxazole derivatives with moderate to good yields.     

l-Proline-catalyzed five-component domino reaction leading to multifunctionalized 1,2,3,4-tetrahydropyridines

Multifunctionalized 1,2,3,4-tetrahydropyridines are concisely synthesized in good yields via l-proline-catalyzed or l-proline/FeCl₃-cocatalyzed one-pot multicomponent reactions (MCRs). The MCRs involve a domino hydroamination/prins reaction/Mannich-type reaction/intramolecular dehydration-cyclization process. The molecular structure of 5baa, one of multifunctionalized 1,2,3,4-tetrahydropyridines, was confirmed by single-crystal X-ray diffraction.     

Exploring the scope of the Gewald reaction: Expansion to a four-component process

An efficient four-component reaction was developed to take advantage of the reactivity of the 2-aminothiophene-3-carbonitrile functionality, which is obtained during the classical three-component Gewald reaction. Various α-methylene bearing ketones were reacted with malononitrile, elemental sulfur, and aryl/heteroarylnitrile derivatives in t-BuOH/NaOH to afford 2-arylthieno[2,3-d]pyrimidin-4-amines in high yields. Preliminary studies revealed the photophysical properties of the products and their potential for use as metal sensors.