基于液芯光纤的激光诱导荧光检测装置的研制及应用

描述了一种激光诱导荧光检测装置。该装置的核心是由低折射率的聚四氟乙烯空心管和流动水溶液构成的液芯光纤,激光作为激发光垂直的照射液芯光纤,光纤内的荧光物质产生的发射光在液芯光纤内发生反射。CCD检测器在液芯光纤的一端对发射光进行检测。应用该装置利用Cu离子催化H2O2氧化罗丹明B(Rh B)造成荧光猝灭对Cu2 进行检测。在线性范围0.4~4μg/L内得到的检出限为0.022μg/L。该方法具有较高的灵敏度,重要原因是CCD的检测消除了液芯光纤中散射的激光的干扰。相比于昂贵的商业荧光仪,本装置能得出更好的检测结果。     

液芯光纤长光路系统吸收测定卡马西平

液芯光纤长光路系统主要由聚光系统和液芯光纤长光路吸收管组成。采用不同长度的光纤管,用该系统吸收测定药物卡马西平(Carbamazepine),实验表明,吸光度要比郎伯-比尔定律预期值大。随着液芯光纤长度的增加,线性区域向更低浓度方向移动,因此,液芯光纤长光路系统更宜于作痕量元素分析。     

液芯光纤长光路法在水溶液中测定Cr,Cu

测量了低折射率液体和水溶液液芯光纤的导光特性和光谱特性，研究了液芯光纤长光路法在７０％乙醇－水溶液体系和５０％二氧六环－水溶液体系中测定Ｃｒ（Ⅵ）、Ｃｕ（Ⅱ）的方法。液芯光纤长１１０ｃｍ时，测定Ｃｒ、Ｃｕ的灵敏度分别为０．０５２、０．０１７ｎｇ．ｍＬ＾－１；线性范围０－２５、０－２５ｎｇ／ｍＬ；ＲＳＤ值为１．０％－４．８％。对国标ＧＳＢＥ５０ ００９－８８样品和明胶中铬的测量值与标准值或ＡＡＳ测量     

液芯光纤预共振和共振喇曼光谱及其应用

在液芯光纤内产生预共振和共振喇曼效应，可大度提高喇曼光谱强度，用波长远离样品吸收峰的激光激发观察到了α－甲基吡啶的预共振喇曼光谱。用长１．１ｍ，内径２００μｍ的液芯光纤，波长５１４．５ｎｍ，功率０．８０Ｗ激光激发获得了β－胡萝卜素在ＣＳ２中的共振喇曼光谱，其浓度为２×１０＾－８ｍｏｌ／Ｌ，比普通方法的样品的浓度低２－３个数量级。     

液芯光纤长光路法测定水溶液中Fe（Ⅱ）

在氟塑料管内充满足拆射率ｎ≥１．３４６的水溶液构成液芯光纤,对其导光特性和光谱特性进行了研究。在此基础上提出了液芯在６１％乙醇或２０％二氧六环水溶液中测定Ｆｅ（Ⅱ）的新天然水中的Ｆｅ（Ⅱ）进行了测定并做了加入已知Ｆｅ（Ⅱ）的回收实验,回收率在９９％－１０１％。     

MicroRNA的超灵敏检测研究进展

综述了最新发展的MicroRNA(miRNA)分析方法, 包括比色、 荧光、 化学发光、 表面增强拉曼、 单分子检测和电化学分析, 并对miRNA检测的发展方向做了展望.     

液芯光纤光度法在乙醇水溶液中测定铂（Ⅱ）,钛（Ⅳ）

采用氟塑料长光纤管，以４２％乙醇水溶液作液芯，组成液芯光纤，基于铂与氯化亚锡，钛与过氧化氢形成黄色络合物在乙醇水溶很稳定，拟定了测定铂，钛的液芯光纤光度法。     

液芯光纤光度法在乙醇水溶液中测定铂(Ⅱ)、钛(Ⅳ)

采用氟塑料长光纤管，以４２％乙醇水溶液作液芯，组成液芯光纤，基于铂与氯化亚锡、钛与过氧化氢形成黄色络合物在乙醇水溶液中很稳定，拟定了测定铂、钛的液芯光纤光度法。该法灵敏度高，用 １ｍ长光纤作吸收池，铂的灵敏度为 ４． ８４５ Ａ／ｍｇ· Ｌ－１，钛的灵敏度为１．４１Ａ／ｍｇ· Ｌ－１（Ａ为吸光度），与常规法（１ｃｍ）比色皿相比灵敏度提高了 １００倍。该法测定了催化剂中铂，煤灰粉中钛，结果与推荐值相符。     

微流控SERS芯片的设计制备及其在细菌检测中的应用

微流控芯片分析平台与表面增强拉曼散射(Surface enhanced Raman scattering,SERS)光谱分析方法结合,充分利用了SERS法所具备的样品前处理简便、检测无损、成分辨识度高以及适宜水环境检测等优点,在生化分析检测领域备受关注。微流控SERS芯片设计及芯片上SERS增强基质的制备是构建微流控SERS芯片分析方法和系统的关键,也是提高检测灵敏度和可重复性的核心问题。该文在介绍微流控SERS芯片的基本构型和功能的基础上,重点综述了微流控SERS芯片上SERS基质的制备方法及其测试效果。基于微电子机械系统(Micro-Electro-mechanical-System,MEMS)加工技术制备的SERS基质,具有纳米粒径有序可控、便于集成制备但增强基质材料种类有限的特点;基于化学沉积和自组装等理化方法制备的SERS基质具有基质种类易拓展、成本低、与微流控通道结合方法灵活等特点。在这些基础上构建的微流控SERS芯片及其分析测试方法和系统,在细菌等许多生化检测领域显示出强大的发展潜力。     

纳米银修饰的超疏水界面用于农药的超灵敏检测

采用化学还原法,在具有不同微观结构的规整的不锈钢网和聚纤维素酯薄膜表面合成了银纳米颗粒.利用氟化试剂对复合界面进行处理,形成超疏水性能的界面,能有效地浓缩目标分子.以罗丹明6G(R 6G)为分析物,纳米银修饰聚纤维素酯薄膜为基底,采用表面增强拉曼散射(SERS)分析了氟化处理前后基底对目标分子的检测能力.实验结果表明,具有超疏水性能的复合基底对R 6G分子的检出限为1 ×10-16 mol/L.以纳米银修饰的不锈钢网和聚纤维素酯两种复合材料为基底,对常用杀虫剂敌百虫的检出限分别为1×10-15 mol/L和1×10-16 mol/L.     

SERS活性光纤光谱微探针研究

用真空蒸镀银岛膜和银溶胶自组装膜两种方法对光纤探针进行表面增强拉曼(SERS)活性修饰,构造了圆锥型SERS活性光纤光谱微探针.选取几个有代表性的分子作为检测样品,得到了低浓度样品的SERS光谱,对样品BVPP的检测下限达到10^-9mol/L.比较两种修饰光纤探针的检测结果可知,银溶胶自组装膜修饰更有优势.     

SERS-Active MIL-100(Fe) Sensory Array for Ultrasensitive and Multiplex Detection of VOCs

The application of metal–organic frameworks (MOFs) as SERS-active platforms in multiplex volatile organic compounds (VOCs) detection is still unexplored. Herein, we demonstrate that MIL-100 (Fe) serves as an ideal SERS substrate for the detection of VOCs. The limit of detection (LOD) of MIL-100(Fe) for toluene sensing can reach 2.5 ppm, and can be even further decreased to 0.48 ppb level when “hot spots” in between Au nanoparticles are employed onto MIL-100 (Fe) substrate, resulting in an enhancement factor of 10¹⁰. Additionally, we show that MIL-100(Fe) substrate has a unique “sensor array” property allowing multiplex VOCs detection, with great modifiability and expandability by doping with foreign metal elements. Finally, the MIL-100(Fe) platform is utilized to simultaneously detect the different gaseous indicators of lung cancer with a ppm detection limit, demonstrating its high potential for early diagnosis of lung cancer in vivo.     

具有表面拉曼增强活性的新型银纳米材料的合成和表征

利用简易无模板湿化学法合成了由纳米片组装的具有三维分级结构的银纳米材料。场发射扫描电子显微镜表明柠檬酸氢二铵在这种结构形成过程中起到很重要的作用。X射线衍射和透射电子显微镜表征进一步证明了这种结构的形成。此外本文还对这种分级结构进行了紫外和拉曼表征。这种新型的银纳米结构有望作为一种高灵敏度的表面拉曼增强基底。     

具有表面拉曼增强活性的银纳米材料的合成和表征(英文)

利用简易无模板湿化学法合成了由纳米片组装的具有三维分级结构的银纳米材料。场发射扫描电子显微镜表明柠檬酸氢二铵在这种结构形成过程中起到很重要的作用。X射线衍射和透射电子显微镜表征进一步证明了这种结构的形成。此外本文还对这种分级结构进行了紫外和拉曼表征。这种新型的银纳米结构有望作为一种高灵敏度的表面拉曼增强基底。     

Ultrasensitive one-step rapid detection of ochratoxin A by the folding-based electrochemical aptasensor

A one-step electrochemical aptasensor using the thiol- and methylene blue- (MB-) dual-labeled aptamer modified gold electrode for determination of ochratoxin A (OTA) was presented in this research. The aptamer against OTA was covalently immobilized on the surface of the electrode by the self-assembly effect and used as recognition probes for OTA detection by the binding induced folding of the aptamer. Under the optimal conditions, the developed electrochemical aptasensor demonstrated a wide linear range from 0.1 pg mL⁻¹ to 1000 pg mL⁻¹ with the limit of detection (LOD) of 0.095 pg mL⁻¹, which was an extraordinary sensitivity compared with other common methods for OTA detection. Moreover, as a practical application, this proposed electrochemical aptasensor was used to monitor the OTA level in red wine samples without any special pretreatment and with satisfactory results obtained. Study results showed that this electrochemical aptasensor could be a potential useful platform for on-site OTA measurement in real complex samples.     

Simple Multiresidue Determination of Fluoroquinolones in Bovine Milk by Liquid Chromatography with Fluorescence Detection

Abstract

A simple and sensitive method for the simultaneous determination of five fluoroquinolones (ciprofloxacin, enrofloxacin, danofloxacin, difloxacin, and sarafloxacin) in bovine milk was developed. Protein precipitation from milk samples was achieved by the addition of acetonitrile and o‐phosphoric acid. Acetonitrile was removed with dichloromethane, leaving the fluoroquinolones in the acid aqueous extract. The aqueous extract was analyzed by liquid chromatography with fluorescence detection (LC–FD). The mobile phase was composed of acetonitrile and 10 mM citrate buffer solution of pH 4.5, with an initial composition of acetonitrile‐water (12∶88, v/v) and using linear gradient elution. Norfloxacin was used as an internal standard. The limits of detection found ranged from 1 to 6 ng · mL^?1 and were below the maximum residue limits (MRLs) established by the European Union. The proposed method was applied to the determination of these compounds in different bovine milk samples. Method validation was carried out by a recovery assay.