NEWS

当前用于电致化学发光传感器的量子点探针主要集中在可见光区,这样导致的高背景可能会干扰生物样品的检测分析。随着生物分析应用的需要,近红外量子点(NIR QDs)电致化学发光研究越来越受到关注。     

量子点在电化学生物传感研究中的应用*

量子点( Quantum dots,QDs )由于具有独特的光学、电化学和电致化学发光特性已受到广泛地重视,而利用量子点构建电化学生物传感器则是量子点最有前途的应用领域之一。量子点具有的高比表面积、高表面活性及小尺寸等特性使它对外界的光、电、温度等十分地敏感,外界环境的微小改变就会迅速引起其表面或界面粒子价态和电子转移行为的显著变化,基于生物大分子引起的QDs表面电化学行为变化而构建的电化学生物传感器,其特点是响应灵敏高、速度快且选择性优良。本文对量子点的光学、电化学和电致化学发光特性作了简单介绍,并重点回顾了其在电致化学发光、免疫分析、DNA杂交、蛋白质检测、农药检测和糖类检测电化学生物传感研究中的应用。同时,对量子点在电化学生物传感研究中的应用前景及研究方向进行了评述和展望。     

光导纤维胆固醇生物传感器的研究

将胆固醇酯酶、胆固醇氧化酶和辣根过氧化物酶通过戊二醛交联反应,固定在牛血清蛋白上,制成光纤胆固醇生物传感器的传感膜.此传感器偶合了胆固醇酯水解、胆固醇的氧化和鲁米诺同过氧化氢的化学发光等3种酶催化反应,通过光纤输出的化学发光信号进行检测.测定总胆固醇和自由胆固醇的线性范围均为0.5～20μg/mL,检测下限为0.1μg/mL,响应时间为2min,寿命在2个月以上,适用于血清中总胆固醇和游离胆固醇的测定.     

基于智能手机的可视化生物传感器在即时检测中的研究进展

人体生理指标是衡量健康与否的重要标准。传统的检测方法通常要求单独的实验室、复杂的操作流程且耗费较长的检测时间,难以满足快速诊断和居家健康监测的需求,因此亟需开发便携、快速和精准的现场检测技术。即时检测（Point-of-care testing, POCT）区别于传统实验室检测的主要特征是不需要实验室繁杂的分析过程即可实现生物分子的快速原位检测。智能手机作为日常生活广泛使用的通讯工具,具有独立的操作系统,内置存储功能,还配备高清摄像头,在POCT可视化检测方面有巨大的应用潜力。将各种生物传感技术与智能手机相结合已经发展成为POCT领域的一个新方向。本文对近年来基于智能手机的可视化生物传感器在POCT中的研究进展进行了评述,包括比色传感器、荧光传感器、化学发光传感器和电化学发光传感器等,总结了目前基于智能手机可视化生物传感器在POCT应用中面临的问题,并对其未来发展前景进行了展望。     

NEWS——基于CdS纳米晶的电致化学发光生物传感器（Ⅰ）

南京大学化学化工学院朱俊杰研究组最近研制了一种基于CdS纳米晶的电致化学发光（ECL）生物传感器（Analytical Chemistry,2007,79,5574-5581）。通过自组装与金纳米颗粒放大技术研制成一种新型的纳米晶体非标记型电化学发光生物传感器,并将其运用于LDL的检测。该传感器具有重现性好,响应速度快,稳定性好等优点。半导体纳米晶通过电化学反应产生氧化态或还原态,     

苦杏仁甙化学发光生物传感器

将具有分子识别功能的β－葡萄糖甙酶和能进行换能反应的Ｌｕｍｉｎｏｌ分别固定在壳质胺和大孔阴离子交换剂的柱中,组成流动注射系统。苦杏仁甙在β－葡萄糖甙酶催化下分解生成的ＣＮ＾－（分子识别反应）与溶解氧反应生成超氧阴离子自由基,继而同Ｌｕｎｉｎｌ反应产生化学发光（换能反应）。这一新型生物传感器的化学发光强度与苦杏杜甙量在１～２００ｕｇ之间呈良好线性关系,检出限为０．３ｕｇ,相对标准偏差为３．１％,并具     

玻璃载体表面脱氧核糖核酸的固定及其化学发光检测

用硅烷化偶联剂把ＤＮＡ直接共价固定在载玻片表面，将辣根过氧化物酶标记的探针与之进行核酸杂交，杂交后用增强的化学发光检测。方法的检出限为７５ｐｇ。研究了ＤＮＡ分子固定在玻璃载体表面的各种条件，并建立了在玻璃载体表面进行核酸杂交的体系，为研究光纤ＤＮＡ生物传感器打下了基础。     

生物电子学—现代分析化学新发展的重要领域

生物电子学技术是基于电子学与生物技术的发展而诞生的新领域。本文阐述并展望在这领域的最新发展。包括:生物计算机与分子计算机,生物传感器,酶电极的生物催化作用,基于离子电极和生物离子学的生物传感器,导电聚合物传感器等。     

共反应试剂增强电致化学发光信号生物传感器

在电致化学发光（ECL）生物传感器的构建中,利用共反应试剂促进发光基团的发光效率是一种常见、方便且非常有效的方法. 然而,如何更好地利用共反应试剂使其更加有效地与发光基团作用是提高该类生物传感器灵敏度的重要因素. 本文结合作者课题组部分工作综述了三种共反应试剂放大ECL信号的构建：共反应试剂内置于检测底液;共反应试剂共存于电极表面;酶促生成共反应试剂,并提出了今后ECL信号放大构建的展望.     

基于血红蛋白/硒化镉量子点多层膜的H2O2生物传感器

合成了水溶性硒化镉(CdSe)量子点,利用组装技术和静电吸附作用,将带正电荷的血红蛋白(Hb)和带负电荷的CdSe量子点层层组装到壳聚糖(chit)修饰的玻碳电极(GCE)表面,构建基于{Hb/CdSe}n多层膜的无电子媒介体的电流型生物传感器({Hb/CdSe}3/chit/GCE).运用紫外-可见吸收光谱、电致化学发光、交流阻抗和循环伏安技术来表征修饰膜,并研究传感器的作用机理、性能及分析应用.结果表明:与量子点薄膜法及量子点/血红蛋白复合物法等固载血红蛋白的其他方法相比,层层组装法能显著提高血红蛋白的固定量,保持血红蛋白的生物活性,增强传感器的灵敏度和稳定性.传感器检测H2O2的线性范围为4.0×10-8～4.8×10-6 mol·L-1(r=0.999 1),检测限为2.0×10-8mol·L-l.多层膜的电致化学发光研究,表明修饰电极有望用于电致化学发光传感器的制备.     

A study of the chemiluminescence of some acidic triphenylmethane dyes

Chemiluminescence was observed when some acidic triphenylmethane dyes were oxidized with hydrogen peroxide in alkaline solution. Trace amounts of Co(II) catalysed this chemiluminescent reaction strongly, especially in the presence of the cationic surfactant cetyltrimethylammonium bromide. The chemiluminescence spectra of some compounds and the absorption spectra of some products of the chemiluminescent reactions were investigated, and some acidic triphenylmethane dyes were studied by the Hückel molecular orbital method. On the basis of these investigations, a possible mechanism for this chemiluminescent reaction, and an initial explanation for the relationship between the structure of the reagents and their chemiluminescent behaviour were proposed. The optimum conditions for use of some of the chemiluminescent reaction systems were selected by means of the modified simplex method, and a chemiluminescent analytical method for determination of ultratrace amounts of cobalt was established, with a detection limit of 5 pg/ml. It was used for analysis of natural water samples, and good results were obtained.     

Recent developments, characteristics, and potential applications of electrochemical biosensors.

The objective of this study is to analyze the technical importance, performance, techniques, advantages, and disadvantages of the biosensors in general and of the electrochemical biosensors in particular. A product of reaction diffuses to the transducer in the first generation biosensors (based on Clark biosensors). The mediated biosensors or second generation biosensors use specific mediators between the reaction and the transducer to improve sensitivity. The second generation biosensors involve two steps: first, there is a redox reaction between enzyme and substrate that is reoxidized by the mediator, and eventually the mediator is oxidized by the electrode. No normal product or mediator diffusion is directly involved in the third generation biosensors, direct biosensors. Based on the type of transducer, current biosensors are divided into optical, mass, thermal, and electrochemical sensors. They are used in medical diagnostics, food quality controls, environmental monitoring, and other applications. These biosensors are also grouped under two broad categories of sensors: direct and indirect detection systems. Moreover, these systems could be further grouped into continuous or batch operation. Therefore, amperometric biosensors and their current applications are focused on more in detail since they are the most commonly used biosensors in monitoring and diagnosing tests in clinical analysis. Problems related to the commercialization of medical, environmental, and industrial biosensors as well as their performance characteristics, their competitiveness in comparison to the conventional analytical tools, and their costs determine the future development of these biosensors.     

Chemiluminescence behavior based on oxidation reaction of rhodamine B with cerium(IV) in sulfuric acid medium

The chemiluminescence (CL) of the rhodamine B (RhB)-cerium(IV) system was investigated by flow-injection. Rhodamine B was suggested to be a suitable chemiluminescent reagent in acidic conditions. When the concentration of rhodamine B was 100 mg l⁻¹ and cerium sulfate was 1.6 mmol l⁻¹ in sulfuric acid, the chemiluminescent intensity was found to be highest by using 0.3 mol l⁻¹ sulfuric acid as a carrier solution. The particular chemiluminescent system could tolerate such distinct acidic environments that it was utilized for detecting many compounds that are stable in acidic solutions. Furthermore, by virtue of IR, UV-Vis and luminescence spectroscopic measurements, the chemiluminescent behavior of rhodamine B was studied and a possible mechanism for this chemiluminescent reaction was proposed. The emitter was affirmed to be a radical species due to one of the oxidation products of RhB; the chemiluminescent emissive wavelength was about 425 nm.     

纳米粒子在电化学DNA生物传感器研究中的应用

简要介绍了电化学DNA生物传感器的原理和分类,对纳米粒子在电化学DNA生物传感器研究中的应用进行了详细评述.     

Microwave‐assisted synthesis of copolymers of luminol with anisidine: Effect on spectral,thermal and fluorescence characteristics

With the aim to investigate variation in the spectral, morphological, and fluorescence characteristics of a chemiluminescent moiety upon copolymerization with an aniline derivative, the present preliminary work reports for the first time the microwave‐assisted copolymerization of luminol and o‐anisidine in acidic and basic media. Characterization of the resulting copolymers was performed by Fourier transform infrared spectroscopy, UV‐visible studies, fluorescence studies, X‐ray diffraction, and transmission electron microscopy measurements. Polymerization of luminol and its copolymers was noticed to be different in acidic and basic media, which was confirmed by IR analysis while UV‐visible as well as fluorescence studies revealed a major decrease in the intensity of the peaks associated with polyluminol that reflected the quenching nature of o‐anisidine. Peak broadening at higher loading of o‐anisidine comonomer confirmed intense interaction of the 2 monomers via hydrogen bonding. To predict the possible use of luminol copolymers as biosensors, bovine serum albumin was chosen as a model protein for performing the adsorption studies. Results revealed that the copolymers reflected immense potential to be used as a protein biosensor.     

电聚高分子膜固定化酶生物传感器及其进展

本文将电化学聚合高分子膜固定膜酶制备的生物传感器分为以下三种主要类型，并分别 就其发展概况和发展方向进行了评述。即：以溶解氧为电子受体的的生物传感器（第一代电流型生物传感器）；以非氧介全为电子受体的生物传感器（第二代电流型生物传感器）和电子在酶和聚合高分膜之间直接进行转移的传感器（第三代电流型生物传感器）。     

Anorganische Chemilumineszenz. Traditionelle Experimente in neuem Licht

Clearly visible chemiluminescence experiments are comparably rare in anorganic chemistry. Apart from the extensively described reactions of the white phosphorus, only the chemiluminescent oxidations of “Wöhlers siloxene” and the chemiluminescent appearances of singlet oxygen might be commonly known. The here described anorganic chemiluminescent experiments take up other well known, entirely anorganic reactions and demonstrate their good visibility even for lectures. Thought has been given to halogen, earth alkaline, ammonia and manganese reactions.     

功能碳黑修饰的丝网印刷碳糊电极葡萄糖生物传感器的特性与机理

从碳黑表面引发苯乙烯磺酸钠的原子转移自由基聚合制备了聚(苯乙烯磺酸钠)改性碳黑(CB-g-PSS),并分别以掺杂和沉积两种不同方式修饰电极的生物敏感膜,再在生物敏感膜上吸附固定葡萄糖氧化酶,制作了两种葡萄糖氧化酶传感器,得到了不同的效果.实验结果表明,将CB-g-PSS与成膜材料掺杂制作的生物传感器与无修饰传感器相比,响应灵敏度下降了1/3;将CB-g-PSS沉积修饰丝网印刷碳糊电极制作的传感器与无修饰传感器相比,响应灵敏度提高了2倍,且对1.1～33.3 mmoL/L的葡萄糖待测样本,RSD均＜7%,稳定性良好,有较高的应用价值.通过实验分析了CB-g-PSS以不同方式修饰电极的工作机理,结果表明,选择正确的修饰方式,能够发挥CB-g-PSS的导电效应及纳米效应,使其有利于酶的固定,提高响应灵敏度并改善酶促反应动力学特性.     

Chemiluminescence detection of five-membered heteroaromatic compounds using electrogenerated tris(2,2'-bipyridine)-ruthenium(III).

Heteroaromatic compounds, such as 2,5-dimethylthiophene, 2,5-dimethylpyrrole, and 2,5-dimethylfuran, were found to act as reducing agents for the tris(2,2'-bipyridine)ruthenium(III), Ru(bpy)3(3+), chemiluminescent reaction. In order to characterize the chemiluminescent reaction of Ru(bpy)3(3+) with heteroaromatic compounds, we have investigated various mono-, di-, and tri-heteroaromatic compounds. The pi-electron density and stability of aromatic rings influence the chemiluminescent efficiency of the reaction. Above all, 2,5-dimethylthiophene produced strong chemiluminescence under acidic conditions. In addition, we confirmed that the rate of the chemiluminescent reaction of Ru(bpy)3(3+) with 2,5-dimethylthiophene is very fast.