导数-同步荧光法同时测定苯甲酸和水杨酸

本文建立了一种同时测定苯甲酸、水杨酸的新方法.苯甲酸、水杨酸的检测限分别为 0.026 μg/mL,0.083 μg/mL;相对标准偏差分别为 1.8％和 3.1％.将该方法用于商品杀菌防腐剂中苯甲酸及水杨酸的同时测定,结果满意.     

同步荧光法同时测定苯甲酸和水杨酸的研究

根据苯甲酸与水杨酸在酸性条件下荧光光谱出现的差异，用同步荧光法同时测定其混合物中二组份。苯甲酸及水杨酸的检测限分别为０．２４μｇ／ｍＬ和０．２５μｇ／ｍＬ相对标准偏差分别为１．３％和１．２％。方法用于商品杀菌腐剂中苯甲酸与水杨酸的同时测定，结果满意。     

同步荧光法同时测定四环素和脱水四环素

本文提出了同步荧光法同时测定四环素（ＴＣ）和脱水四环素（ＡＴＣ）新方法。ＴＣ和ＡＴＣ与铝离子形成络合物后分别在３８７／４６２ｎｍ和４８０／５３８ｎｍ处发射增强的荧光；加入十二烷基硫酸钠（ＳＬＳ）后，ＴＣ和ＡＴＣ络合物的荧光强度分别增强４．５倍和８倍。其同步荧光峰在△λ＝６０ｎｍ时完全分离，在ＴＣ和ＡＴＣ浓度比为２０：１～１：２０范围内可同时测定ＴＣ和ＡＴＣ。本法测定尿液中ＴＣ和ＡＴＣ的回收率为９４     

同步荧光法同时测定强力霉素和土霉素

本文提出了表面活性剂增敏碱性降解同步荧光测定强力霉素（ＤＣ）和土霉素（ＯＴＣ）新法。土霉素和强力霉素在０．１ｍｏｌ／ＬＮａＯＨ溶液中反应，生成强荧光降解物，加入十六烷基三甲基溴化铵（ＣＴＭＡＢ）后，荧光强度分别增加４．２倍和１０．７倍。其同步荧光峰在△λ＝７０ｎｍ时基本分离，ＯＴＣ和ＤＣ浓度比在１＋４０～１０＋１范围内可同时测定ＯＴＣ和ＤＣ。本法测定尿液中ＯＴＣ和ＤＣ的回收率为９０％～１０４％。     

十二烷基苯磺酸钠与苯酚的导数同步荧光法同时测定

研究了十二烷基苯磺酸钠和苯酚及其混合物在pH 6.0的磷酸二氢钠-磷酸氢二钠缓冲液中的一阶导数同步荧光光谱,确定了最佳实验条件:波长差Δλ=60 nm,十二烷基苯磺酸钠的测定波长为224 nm,苯酚的测定波长为258 nm,建立了一阶导数同步荧光法同时测定混合物中十二烷基苯磺酸钠和苯酚的新方法。十二烷基苯磺酸钠和苯酚的线性范围分别为0.05~8.00 mg/L和0.10~5.50 mg/L;线性相关系数分别为0.995 5和0.999 7;检出限分别为8.4μg/L和5.3μg/L;回收率分别为95%~100%和98%~102%;相对标准偏差分别为3.8%和1.9%。该方法可用于水中十二烷基苯磺酸钠和苯酚的同时检测,结果满意。     

同步荧光法同时测定水溶解态的蒽和芘

利用PAHs具有高的荧光量子产率,同步荧光法具有快速、灵敏、选择性较好的优点,建立了同时测定水溶液中溶解态蒽和芘的方法。所建方法测定蒽和芘的线性范围分别为1.0×10-8~2.0×10-7mol/L和5.0×10-9~3.5×10-7mol/L,检出限分别为1.69×10-9mol/L、8.42×10-10mol/L,相对标准偏差分别为2.90%、2.34%(n=5)。运用所建方法尝试了自来水样品的测定。     

固定波长同步荧光法同时分析2,2′—二羟基联苯和4—羟基联苯

建立了２，２′－二羟基联苯和４－羟基联苯的同时同步荥光分析法，方法简便快速，２，２′－二羟基联苯和４－羟基联苯的线性范围均为０～８μｍ／ｍＬ，检出限分别为６１ｎｇ／ｍＬ和８７ｎｇ／ｍＬ。     

导数—同步荧光法同时测定苯甲酸和水杨酸

本文建立了一种同时测定苯甲酸、水杨酸的新方法。苯甲酸、水杨酸的检测限分别为０．０２６μｇ／ｍＬ，０．０８３μｇ／ｍＬ；相对标准偏差分别为１．８％和３．１％。将该方法用于商品镣菌防腐剂中苯甲酸及水杨酸的同时测定，结果满意。     

同步-偏振-导数荧光法同时测定三种苯二酚异构体的研究

苯二酚的三种异构体, 由于其吸收光谱和荧光光谱均重叠严重, 不能用常规分光光度法和荧光法进行同时测定. 而以λ＝0 nm进行同步扫描时, 在350～500 nm之间具有相似的荧光光谱特征, 其荧光强度有良好的加和性, 可以对三者进行总量测定. 研究还发现三种苯二酚异构体与Cu^2＋和异烟肼形成1∶1∶2的配位合物时, 用Δλ＝30 nm进行同步扫描并采用偏振和一阶导数法, 间苯二酚的导数荧光峰位于260 nm处, 对苯二酚的导数荧光峰位于320 nm处, 两者能很好分开, 而此时邻苯二酚荧光峰消失, 因此可在三者的混合物中分别测定间、对苯二酚, 然后再从总量中减去间、对苯二酚的含量, 从而测到邻苯二酚的浓度, 因此本工作通过上述方法可对三种苯二酚异构体进行同时测定. 其线性范围均在3×10^－6～5×10^－4 mol/L之内, 间苯二酚和对苯二酚的检出限分别是2.5×10^－7 mol/L和3.1×10^－7 mol/L; 其混和物总量的检出限是4.5×10^－7 mol/L, RSD均在5%以下. 该方法简便快速, 有良好的准确性和重复性, 用于环境水样中三种苯二酚的同时测定, 获得满意结果.     

Ultrasensitive Detection of Hepatitis C Virus DNA Subtypes Based on Cucurbituril and Graphene Oxide Nano-composite

Infectious of hepatitis C viruses(HCVs)lead to hepatic fibrosis,cirrhosis even hepatoma.Developing rapid and sensitive diagnostic method for HCV is of great importance.Based on the host-and-guest interaction between cucurbit[7]uril(CB[7])and methylene blue(MB),a CB[7]-graphene nano-composite(CB[7]-N3-GO)is raised for the electrochemical detection of HCV DNA.The method is able to linearly detect the HCV nucleic acid in the range of 0.2—10 nmol/L with detection limit as low as 160.4 pmol/L.The proposed detection strategy is able to discriminate the lb and 6k subtypes of HCV and has a prospective potential in the blood screen for HCV in clinical diagnosis.     

氧化石墨烯荧光传感器

氧化石墨烯因其独特的光学、表面、机械、电学及热学性质在诸多领域都具有良好的应用前景。利用氧化石墨烯能够有效猝灭荧光体(染料分子、量子点及上转换纳米材料)荧光的特性,结合相关生物分析技术,相继开发了各种荧光传感器。本文综述近年来氧化石墨烯荧光传感器的基本原理及研究进展,主要讨论氧化石墨烯荧光传感器在重金属离子、DNA、蛋白质及生物小分子的分析应用,并对该领域的应用前景进行了展望。     

荧光核酸适配体功能化氧化石墨烯生物传感器用于快速检测氯霉素

开发了一种无标记和快速的检测方法基于氧化石墨烯（GO）和荧光功能性G-四聚体探针（FGP），可用于定量检测氯霉素（CAP）.FGP由氯霉素核酸适配体和富含G碱基的核酸序列组成.核酸适配体用于结合CAP，并且由富含G碱基的核酸序列在K⁺，Na⁺离子的作用下形成的G-四聚体，然后与硫磺素T（ThT）结合后用作信号分子.在没有CAP的情况下，FGP通过π-π堆积相互作用被吸附到GO的表面上，阻碍了G-四聚体的形成导致溶液中的荧光强度低.在加入CAP时，FGP的核酸适配体部分可识别并结合CAP以形成复合物，导致其从GO解吸.因此，游离的富含G的碱基序列可以形成G-四聚体结构并与ThT结合，导致溶液的荧光强度增加.我们观察到荧光强度增加与CAP浓度在2~20 nmol/L范围内呈线性关系，检测限为1.45 nmol/L.此外，该检测系统用于检测加标牛奶中的CAP，回收率在93.2%~103.3%之间.这些结果表明，开发的方法可用于有效检测实际样品中的CAP.     

基于氧化石墨烯荧光适体传感器的胰岛素检测

采用荧光基团(FAM)标记的核酸适体作为识别元件,氧化石墨烯为淬灭剂,建立了一种高选择性、高灵敏度的核酸适体传感器.核酸适体与氧化石墨烯结合后,荧光淬灭,此时溶液无荧光;加入胰岛素后,溶液中荧光得到恢复.利用荧光分析法检测加入胰岛素前后,溶液中荧光强度的变化,获取了荧光适体传感器的线性度和灵敏度,实现对胰岛素浓度的测定.结果表明,在5×10-8 ～ 1×10-5 mol/L范围内,胰岛素的浓度与溶液中荧光强度有良好的线性关系,检出限为10 nmol/L.采用此方法检测胰岛素,操作简便,检测速度快,准确性高,选择性好,检出限低.     

固定波长同步荧光光谱参数的理论计算

基于荧光激发光谱和发射光谱对波长呈高斯分布的设定,本文推导出固定波长同步荧光光谱峰峰值位置、相对强度和半峰宽度等3个主要光谱参数的理论计算式。所提出的计算式应用于若干荧光物质光谱参数的计算,并和实测值、文献计算值作了对照。结果表明,和文献计算方法相比,本法与所研究物质的实际光谱参数较为接近,可为固定波长同步荧光光谱参数的理论计算提供一有效方法。     

基于荧光共轭聚电解质的生物分子检测

共轭聚电解质综合了传统共轭聚合物的光电性质和聚电解质的水溶性特点,使其在新一代化学生物荧光传感器中获得多种应用。本文总结了近五年来报道的共轭聚电解质（聚芴、聚噻吩、聚苯撑乙烯、聚苯撑乙炔等）用于检测生物分子的研究进展,并对共轭聚电解质的应用前景进行了展望。     

Fabrication of Orange Fluorescent Boron-Doped Graphene Quantum Dots for Al3+ Ion Detection

Aluminum is a kind of metal that we often encounter. It can also be absorbed by the human body invisibly and will affect our bodies to a certain extent, e.g., by causing symptoms associated with Alzheimer’s disease. Therefore, the detection of aluminum is particularly important. The methods to detect metal ions include precipitation methods and electrochemical methods, which are cumbersome and costly. Fluorescence detection is a fast and sensitive method with a low cost and non-toxicity. Traditional fluorescent nanomaterials have a high cost, high toxicity, and cause harm to the human body. Graphene quantum dots are a new type of fluorescent nanomaterials with a low cost and non-toxicity that can compensate for the defects of traditional fluorescent nanomaterials. In this paper, c-GQDs and o-GQDs with good performance were prepared by a bottom-up hydrothermal method using o-phenylenediamine as a precursor and citric acid or boric acid as modulators. They have very good optical properties: o-GQDs exhibit orange fluorescence under UV irradiation, while c-GQDs exhibits cyan fluorescence. Then, different metal ions were used for ion detection, and it was found that Al³⁺ had a good quenching effect on the fluorescence of the o-GQDs. The reason for this phenomenon may be related to the strong binding of Al³⁺ ions to the N and O functional groups of the o-GQDs and the rapid chelation kinetics. During the chelation process, the separation of o-GQDs’ photoexcited electron hole pairs leads to their rapid electron transfer to Al³⁺, in turn leading to the occurrence of a fluorescence-quenching phenomenon. In addition, there was a good linear relationship between the concentration of the Al³⁺ ions and the fluorescence intensity, and the correlation coefficient of the linear regression equation was 0.9937. This illustrates the potential for the wide application of GQDs in sensing systems, while also demonstrating that Al³⁺ sensors can be used to detect Al³⁺ ions.     

用同步荧光法研究细胞色素C在水溶液中的存在形态

用同步荧光光谱法研究细胞色素Ｃ在水溶液中的存在形态，发现细胞色素Ｃ中色氨酸残基的同步荧光光谱随浓度改变而发生变化，在较稀的溶液中，只观察到色氨酸残基的一个荧光峰，在较浓的溶液中也观察到一个荧光峰，而在这两个浓度之间时，这两个峰共存，可能反映了细胞色素Ｃ在不同浓度溶液中聚集状态的不同，当向存在两个荧光峰的溶液中加入不同浓度的脲，在一定脲浓度范围内，细胞色素Ｃ不发生变性，脲的作用使细胞色素Ｃ的单体浓度     

Fluorescence and Sensing Applications of Graphene Oxide and Graphene Quantum Dots: A Review

Graphene oxide and graphene quantum dots are attractive fluorophores that are inexpensive, nontoxic, photostable, water‐soluble, biocompatible, and environmentally friendly. They find extensive applications in fluorescent biosensors and chemosensors, in which they serve as either fluorophores or quenchers. As fluorophores, they display tunable photoluminescence emission and the “giant red‐edge effect”. As quenchers, they exhibit a remarkable quenching efficiency through either electron transfer or Förster resonance energy transfer (FRET) process. In this review, the origin of fluorescence and the mechanism of excitation wavelength‐dependent fluorescence of graphene oxide and graphene quantum dots are discussed. Sensor design strategies based on graphene oxide and graphene quantum dots are presented. The applications of these sensors in health care, the environment, agriculture, and food safety are highlighted.     

Homogeneous Detection of Trypsin in Protein Mixtures Based on Fluorescence Resonance Energy Transfer between Anionic Conjugated Polymer and Fluorescent Probe

Herein we describe a novel and simple conjugated polymer‐fluorescent probe based platform for trypsin detection from protein mixtures in homogeneous solution. This platform takes advantage of specific interaction between the probe and the active site of trypsin and the electrostatic interaction between the polymer and the protein to mediate energy transfer between the polymer and the probe. This method does not require any separation steps, which should facilitate high‐throughput protease screening and drug discovery.