核酸适配体传感器在黄曲霉毒素B1检测中应用研究进展北大核心CSCD

核酸适配体作为一种新型识别分子,具有亲和力高、稳定性强、制备成本低、特异性强等优点,但其自身不具有信号转换功能,它与靶标分子特异性结合过程,不可产生被检测的物理化学信号。因此,需将核酸适配体与靶标分子特异性识别结合过程转为易于被检测的物理化学信号变化的过程。根据信号转换方式的不同,可将适配体生物传感器分为荧光适配体传感器、比色适配体传感器、电化学适配体传感器和表面拉曼散射适配体传感器。本文对基于以上4种检测信号的核酸适配体生物传感器在黄曲霉毒素(AFB1)检测方面的应用进行综述,并概述该类传感器应用前景和当前面临的挑战。     

适配体生物传感器在病原微生物检测中的应用

适配体是通过指数富集系统进化技术(SELEX)体外筛选得到的一类能够特异性地结合小分子物质、蛋白,甚至整个细胞的寡核苷酸序列.由于具有制备简便、易于修饰、稳定性好等特点,适配体已广泛应用于构建生物传感器,实现对病原微生物的识别和检测.本文在阐述适配体基本原理的基础之上,结合近年来病原微生物适配体研究领域的最新研究成果,综述以病原微生物为目标的适配体筛选技术的最新进展;列举目前已经筛选获得的病原微生物(原生生物、病毒、细菌)适配体;综述适配体生物传感器在病原微生物检测中的应用.并展望了适配体生物传感器在病原微生物检测领域的发展趋势.     

适配体电化学生物传感器研究进展

由于制备简便、易修饰、稳定性好和结合目标物范围广等特点,基于适配体的生物传感器研究工作一直得到广大科研工作者的关注.本文在阐述适配体基本原理的基础之上,结合近年来电化学适配体生物传感器研究领域的最新研究成果,对电化学技术在适配体生物传感器研究领域中的最新进展作一综述与展望.     

高灵敏光学和电化学适配体传感器在真菌毒素快速检测中的研究进展

高灵敏的生物传感器在痕量真菌毒素污染的快速检测中备受关注.适配体除具有与抗体类似的高选择性外,还具有可体外合成和易修饰等独特优势,已成为现阶段生物传感器中常用的识别元件.随着指数富集的配体系统进化(SELEX)技术的发展,筛选获得的真菌毒素适配体越来越多,为不同真菌毒素的检测提供了基础条件,而适配体结合现代新型纳米材料...     

适配体电化学传感器检测汞离子进展

适配体是一小段经体外筛选得到的寡核苷酸序列。适配体中的胸腺嘧啶(T)碱基可与Hg~(2+)形成比双链DNA更加稳定的T-Hg~(2+)-T结构。利用该性质结合电化学测量方法可制作检测Hg~(2+)的特异性强、灵敏度高的适配体电化学传感器,并建立微量Hg~(2+)的检测方法。该文对近年来发展的检测Hg~(2+)的适配体电化学传感器进行了综述和总结,对文献报道的几类传感器的构建过程和检测机理进行了详述,对检测方法的优缺点进行了分析。最后,对此类传感器今后的发展方向提出了展望,引用文献83篇。     

基于适配体的生物传感器在双酚A检测中的应用

双酚A(BPA)的快速、准确检测对于对食品安全和公共卫生至关重要.基于适配体的生物传感器是一种集生物、化学、物理及纳米技术为一体的新型高效传感器,在BPA分析领域有巨大的应用潜力.本文在对BPA适配体简要分析的基础上,综述了基于适配体的多种生物传感器的检测原理以及在BPA检测中的最新应用进展,并对其未来发展方向进行了展...     

核酸适配体生物传感器在农残检测中的研究进展EI北大核心CSCD

由于核酸适配体具有特异性强、亲和力高、制备方便、易修饰、稳定性好、目标物多样性等特点,基于适配体的传感器研究工作一直是广大科研工作者的研究热点。相较于具有特异性识别的生物酶的使用,核酸适配体在农药残留检测中的应用正在发展中,具有广阔的前景。本文主要介绍近两年来核酸适配体生物传感器在农药分子检测领域的相关进展。     

基于结构变化适体及信号探针DNA修饰的Au纳米粒子放大作用的腺苷电化学传感器

适配体（aptamer）是利用体外筛选技术——指数富集的配体系统进化技术（SELEX）,从核酸分子文库中得到的寡核苷酸片段。适配体能与多种目标物质高特异性、高选择性的结合,被广泛应用于生物传感器、药物检测、医学诊断和治疗等方面。青岛科技大学化学与分子工程学院张书圣课题组将纳米技术与适配体技术结合,研制成功一种新型的腺苷分子传感器（Anal．Chem．,2008,80：8382-8388）。     

核酸适配体生物传感器在农残检测中的研究进展

由于核酸适配体具有特异性强、亲和力高、制备方便、易修饰、稳定性好、目标物多样性等特点,基于适配体的传感器研究工作一直是广大科研工作者的研究热点。相较于具有特异性识别的生物酶的使用,核酸适配体在农药残留检测中的应用正在发展中,具有广阔的前景。本文主要介绍近两年来核酸适配体生物传感器在农药分子检测领域的相关进展。     

光学适配体传感器检测赭曲霉毒素A的研究进展

赭曲霉毒素A(Ochratoxin A,OTA)是真菌产生的次级代谢产物,性质稳定,不易去除,人体摄入后将产生严重的健康危害。数十年来,核酸适配体不断发展,成为生物传感器的重要识别元件之一,适体传感器被广泛用于生物、医药、疾病等分析检测。本文总结了用于检测OTA的经典方法和基于核酸适配体的生物传感器方法,并主要从光学适配体传感器方面阐述了近年用于检测赭曲霉毒素A的适配体传感器,并对其进行了总结和展望。     

Protein detection by nanopores equipped with aptamers

Protein nanopores have been used as stochastic sensors for the detection of analytes that range from small molecules to proteins. In this approach, individual analyte molecules modulate the ionic current flowing through a single nanopore. Here, a new type of stochastic sensor based on an αHL pore modified with an aptamer is described. The aptamer is bound to the pore by hybridization to an oligonucleotide that is attached covalently through a disulfide bond to a single cysteine residue near a mouth of the pore. We show that the binding of thrombin to a 15-mer DNA aptamer, which forms a cation-stabilized quadruplex, alters the ionic current through the pore. The approach allows the quantification of nanomolar concentrations of thrombin, and provides association and dissociation rate constants and equilibrium dissociation constants for thrombin·aptamer interactions. Aptamer-based nanopores have the potential to be integrated into arrays for the parallel detection of multiple analytes.     

基于微磁珠分离技术的适配体实时定量PCR检测方法

利用适配体的识别能力和可扩增性, 构建了基于微磁珠分离技术的适配体实时定量聚合酶链式反应(PCR)检测方法. 通过微磁珠偶联的互补链与适配体序列之间的碱基配对结合, 有效除去溶液中未与靶分子结合的适配体序列, 采用实时定量PCR技术测定上清液中结合态的适配体序列浓度, 从而间接实现对靶分子的定量检测. 分别选取代表生物大分子和有机小分子的凝血酶和ATP作为检测对象, 验证了该方法的普适性. 研究结果表明, 在获取特异性适配体序列后, 仅需简单优化其互补链序列, 即可对超低含量的凝血酶和ATP进行准确定量, 检出限分别为50 pmol/L和5 μmol/L. 该方法具有同时适用于高特异性和高灵敏度地检测生物大分子和有机小分子的优势.     

Investigation of the interaction between a bivalent aptamer and thrombin by AFM

Aptamers are a new class of molecular probes for protein recognition, detection, and inhibition. Multivalent aptamer-protein binding through aptamer assembly has been currently developed as an effective way to achieve higher protein affinity and selectivity. In this study, the specific interaction between bivalent aptamer Bi-8S and thrombin has been measured directly and quantitatively by atomic force microscopy to investigate the unbinding dynamics and dissociation energy landscape of the multivalent interaction. Bivalent aptamer Bi-8S contains thrombin's two aptamers, 15apt and 27apt, which are linked by eight spacer phosphoramidites. The results revealed the sequential dissociation of the two aptamers. Moreover, the dynamic force spectroscopy data revealed that the 27apt's binding to the thrombin remains largely unaffected by the eight-spacer phosphoramidites within Bi-8S. In contrast, the eight-spacer phosphoramidites stabilized the 15apt-thrombin binding.     

核酸适配体荧光探针在生化分析和生物成像中的研究进展

核酸适配体是指通过体外筛选技术从核酸文库中筛选出来,能够高特异性、高亲和力识别靶标物的寡核苷酸序列,具有靶标类型广泛、合成简单、相对分子质量小、化学稳定性高、易于进行生物化学修饰等优点。 核酸适配体能够通过折叠成特定的二维或三维构型与靶标物特异性结合,加上合适的信号转导机制,为重要靶标物的研究提供理想的分子识别与分子检测探针。 荧光检测技术具有高灵敏、高分辨率、易于实现多元分析等优点。 将核酸适配体的分子识别特性与荧光优异的光学检测性能相结合,在生命科学研究领域有着广泛的应用空间。 本文主要综述了核酸适配体荧光探针常见的分子设计和信号响应方式,及其在细胞成像、亚细胞成像中的应用研究,并对核酸适配体探针目前面临的一些挑战进行了讨论,最后对其未来的发展方向进行了展望。     

基于适配体技术的雌性激素检测方法研究进展

雌激素是一种类固醇激素,属于环境内分泌干扰物,可在人体和动物体内积累并起到类似雌激素的作用,使生物体的内分泌失衡,因此开发简单快速灵敏的雌激素检测方法具有重要意义。核酸适配体是通过指数富集配体系统进化技术(SELEX)筛选得到的一条寡核苷酸序列,能够与靶标高亲和力特异性结合,与传统抗体相比,具有靶标范围广、易合成修饰、稳定性高等特点,因而被广泛用于分析检测领域。该文主要综述了雌激素适配体的筛选进展以及适配体技术在雌激素检测中的应用,并对核酸适配体技术在雌激素检测领域的应用前景进行了展望。     

A label-free and high sensitive aptamer biosensor based on hyperbranched polyester microspheres for thrombin detection

In this paper, we have synthesized hyperbranched polyester microspheres with carboxylic acid functional groups (HBPE-CA) and developed a label-free electrochemical aptamer biosensor using thrombin-binding aptamer (TBA) as receptor for the measurement of thrombin in whole blood. The indium tin oxide (ITO) electrode surface modified with HBPE-CA microspheres was grafted with TBA, which has excellent binding affinity and selectivity for thrombin. Binding of the thrombin at the modified ITO electrode surface greatly restrained access of electrons for a redox probe of [Fe(CN)₆]^3−/4−. Moreover, the aptamer biosensor could be used for detection of thrombin in whole blood, a wide detection range (10 fM–100 nM) and a detection limit on the order of 0.90 fM were demonstrated. Control experiments were also carried out by using bull serum albumin (BSA) and lysozyme in the absence of thrombin. The good stability and repeatability of this aptamer biosensor were also proved. We expect that this demonstration will lead to the development of highly sensitive label-free sensors based on aptamer with lower cost than current technology. The integration of the technologies, which include anticoagulant, sensor and nanoscience, will bring significant input to high-performance biosensors relevant to diagnostics and therapy of interest for human health.     

核酸适配体功能化的稀土上转换纳米材料在生物检测中的应用

稀土上转换纳米材料可以吸收近红外光并发射出可见光或紫外光,在生物传感领域得到了广泛研究。核酸适配体能高特异性和高亲和性地与靶标物结合,被广泛应用于生物传感、疾病诊断等领域。将稀土上转换纳米材料与核酸适配体结合构建的检测体系,可实现对目标物灵敏、高选择性的检测。本文介绍了近几年核酸适配体功能化的稀土上转换纳米材料在生物小分子、蛋白质、核酸、病原微生物、细胞等方面的应用,并展望了其在分析检测领域的发展前景。     

基于适配体亲和毛细管电泳-激光诱导荧光检测的凝血酶分析

以一种高亲和力适配体作为亲和荧光探针,以自建的毛细管电泳-激光诱导荧光(CE-LIF)检测装置为基础,建立了一种高灵敏、快速测定人凝血酶的方法。荧光标记的凝血酶适配体特异性地与凝血酶结合并形成稳定的凝血酶-适配体复合物,采用CE-LIF对复合物进行分离检测,从而测定凝血酶浓度。探讨了盐离子种类及浓度对适配体与凝血酶结合的影响,并在选定的电泳条件下对凝血酶检测的线性范围、检出限和重现性进行了测定。结果表明,盐离子存在的条件下适配体与凝血酶的亲和力降低,不利于两者的结合;人血清溶液中,凝血酶浓度在0.25～10 nmol/L范围内与复合物峰面积具有良好的线性相关性(r20.991),检出限(S/N3)为55.6 pmol/L;精密度和回收率测定结果均能满足分析的要求。     

Homogeneous assays using aptamers

Aptamers are DNA or RNA oligonucleotides that can bind with high affinity and specificity to a wide range of targets such as proteins, metal ions or pathogenic microorganisms. Soluble aptamers and aptazymes have been used as sensing elements for developing homogeneous assays in a solution phase, the whole sensing process being carried out in a homogeneous solution. Contrary to most conventional heterogeneous assays that are time-consuming and labor-intensive, aptamer-based homogeneous assays are simple, easy-to-perform, rapid and do not require immobilization nor washing steps. To our knowledge, this review is the first entirely dedicated to aptamer-based homogeneous assays. Optical detection appears as the most developed technique. Colorimetry represents the simplest sensing mode that occupies a very important position among aptamer-based assays, involving gold nanoparticle aggregation (with unmodified or aptamer-modified gold NPs), the formation of HRP-mimicking DNAzyme with hemin, dye displacement or interactions with a cationic polymer. Fluorescence that is highly sensitive offers the most developed detection mode. Aptamers can be labeled or not, to give rise to turn-on or usually less sensitive turn-off fluorescent assays. Newly reported and thus less developed non-conventional magnetic resonance imaging (MRI) and electrochemistry also recently appeared in the literature, thrombin still remains the main detected target. Homogeneous assays based on aptazyme, an aptamer sequence connected to a known ribozyme motif, are also described in this review, involving optical detection, by colorimetry or fluorescence.     

Recent advances of aptamer sensors

Aptamers are a series of high-affinity and high-specificity oligoneucleotides (single-stranded DNA or RNA) to the target, usually selected by the combinatorial chemistry SELEX technique (systematic evolution of ligands by exponential enrichment). Aptamers have proved to be one kind of novel functional molecules in life science and chemistry. After being labeled by signaling groups, the aptamer probe can conveniently transfer the characteristics of aptamer-target recognition to a form of high-sensitive signal, and the high-affinity, high-specificity measurements of metal ion, organic molecules, nucleic acid, proteins, or cells become possible. This article summarizes the recent advances of aptamer probes in different sensing fields, with special emphasis on aptamer probes as fluorescent sensors.