海洋毒素电化学生物传感器

由藻类产生的海洋毒素对人类健康和环境安全构成了较大威胁,对其进行快速准确的检测是减小海洋毒素危害的有效手段之一。电化学生物传感器具有快速简便、灵敏度高、检测限低和成本低等特点,为检测海洋毒素提供了新的技术途径。目前,应用于海洋毒素检测中的电化学生物传感器主要有免疫传感器、酶传感器和DNA传感器等。本文综述了迄今为止国内外海洋毒素电化学生物传感器研究所取得的成果,并对其当前研究存在的问题和未来发展趋势进行探讨和展望。     

适配体生物传感器在黄曲霉毒素B1检测中的应用

该文首先对黄曲霉毒素B1（AFB1）的相关性质及其传统检测方法进行了介绍,随后概述了近年来基于光学、电化学以及微流控芯片的适配体生物传感器的构建及其在AFB1检测领域中的应用,旨为适配体生物传感器的实际应用提供参考;并通过探讨目前开发的检测方法存在的问题,对适配体生物传感器前景和未来趋势进行了展望。     

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。     

溶胶凝胶法固定抗体制备黄曲霉毒素免疫传感器

利用溶胶凝胶法,将正硅酸乙酯在HCl存在下水解形成的硅溶胶和黄曲霉毒素B1抗体的混合液涂于玻碳电极表面,制备非标记型电化学阻抗免疫传感器。以[Fe(CN)6]3-/4-的磷酸盐缓冲溶液为测试底液,分别研究传感器的循环伏安和交流阻抗行为。实验表明,电极因免疫反应所形成的复合物阻碍了[Fe(CN)6]3-/4-在电极表面的扩散,其氧化还原峰电流明显减小,电子转移阻抗随黄曲霉毒素浓度增加而线性增大。当介质pH=6.5和孵育时间为20 min时,免疫前后传感器的电子转移阻抗变化值最大。在此最佳条件下,传感器电子转移阻抗对黄曲霉毒素响应的线性范围为1.0～10μg/L;检出限为0.1μg/L(S/N=3)。此方法具有高的灵敏度和稳定性,可应用于食品中黄曲霉毒素的测定。     

纳米电化学传感器检测微生物的研究进展

致病微生物是影响人类健康的一类重要微生物。基于纳米材料的电化学免疫生物传感器在致病微生物检测方面具有检测速度快,灵敏度高,检测下限低,成本低等优点。本文综述了几种纳米材料电化学免疫生物传感器的构建和实验研究,分析了各种纳米材料如何改善电化学传感器性能,并具体比较分析了不同纳米电化学生物传感器对各种病原微生物的检测研究,最后,对未来的发展趋势进行了展望。     

基于Nafion-CNNS复合膜构置免标记的AFB1免疫传感器

本文将氮化碳纳米片(g-C₃N₄ nanosheets,CNNS)分散到一定浓度的Nafion溶液中,滴涂至玻碳电极制备修饰电极,而后将黄曲霉毒素B1抗体、黄曲霉毒素B1(AFB1)先后孵育至该修饰电极上,以鲁米诺溶液为电化学发光探针测定免疫作用前后化学发光值,依据前后发光值的差值,构置免标记的用于定量检测黄曲霉毒素B1的电致化学发光免疫传感器。结果表明,免疫结合前后鲁米诺溶液的ECL差值与溶液中黄曲霉毒素B1(AFB1)的含量在1.0量在曲^-4～10.0 ng·mL^-1和10.0～160.0 ng·mL^-1两个区间有着良好的线性关系,对AFB1的检出限为0.1pg·mL^-4,该电致化学发光免疫传感器不但线性范围广,而且检出限超低,可实现对黄曲霉毒素B1的超灵敏检测。     

MicroRNAs电化学生物传感器在乳腺癌检测中的研究进展

MicroRNAs是一类内源性非编码小RNA分子,可调控靶基因的表达。特异性microRNAs的失调在诸如癌症、心血管疾病、免疫疾病、神经退行性疾病和皮肤疾病等的发展过程中起着关键作用,常作为疾病早期诊断和预后的生物标志物。电化学生物传感器由于其灵敏、快速、成本低等优势,已经成为传统microRNAs检测方法的一种很有前途的替代方法。本文综述了基于microRNA电化学生物传感器检测乳腺癌的研究进展,并对其所构建的电化学生物传感器的检测方法进行了分析探讨。     

电化学生物传感器测定甲胎蛋白的研究进展

人体血清中甲胎蛋白(AFP)含量已作为肝癌检测的重要指标,快速而准确地检测血清中的AFP含量对肝癌的早期诊断和预后都有极为重要的作用。传统的酶联免疫法存在分析时间长、前处理繁琐等不利因素。利用免疫技术与电化学检测技术结合起来的电化学免疫传感器,由于具有操作简单、灵敏度高、特异性强及成本低等特点,而得到广泛关注。本文将根据所采用的不同检测方式及修饰材料等方面对近年来电化学免疫传感器检测AFP的研究与应用进行评述,并对其发展趋势进行了展望。     

亲和型生物传感器在生物医学上的应用进展

近年来,生物传感器与纳米技术、流动注射和微流控等新技术的结合,获得了蓬勃而迅速的发展。 亲和型生物传感器是基于生物分子之间的特异的亲和性,即生物活性物质对底物的亲和与键合而建立起来的一种新型传感装置。 它具有特异性好、灵敏度高、成本低、能在复杂的体系中进行在线连续监测等优点,进而在生物医学领域,对生物医学标记物、核酸、蛋白质、病毒、细菌及毒素的检测、药物作用机理的研究、临床用药筛选等方面有着广泛的应用。 本文从光学、电化学、石英晶体微天平传感、表面等离子体共振等几个方面对近年来亲和型生物传感器,特别是用于检测肿瘤标记物的免疫传感器和基于核酸适体的生物传感器在生物医学领域的测定原理和应用现状进行了评述,并对其发展趋势进行了展望。     

用于赭曲霉毒素A检测的电化学适配体生物传感器的研究进展

赭曲霉毒素（Ochratoxin）是一类主要由曲霉菌和青霉菌产生的次生代谢产物,其中赭曲霉毒素A（OTA）的毒性最强。OTA相当稳定,常规的食品加工难以去除,若摄入受OTA污染的食品或药物会对人类造成严重的危害。实现对OTA的灵敏和快速检测是及早发现和处置OTA污染的关键。近年来,核酸适配体因其独特的优点,被作为抗体的替代物用于构建OTA电化学生物传感器。本文介绍了经典的OTA检测方法和基于适配体的电化学生物传感检测方法,从OTA电化学适配体传感器的适配体优化、新型材料应用以及生物信号放大技术的应用等三个方面总结了该生物传感技术的研究现状,并对其未来的发展进行了展望     

A method for the detection of alcohol vapours based on optical sensing of magnesium 5,10,15,20-tetraphenyl porphyrin thin film by an optical spectrometer and principal component analysis

In this work we have proposed a method for the detection of alcohol vapours, i.e. methanol, ethanol and isopropanol, based on the optical sensing response of magnesium 5,10,15,20-tetraphenyl porphyrin (MgTPP) thin films, as measured by optical spectrometry with the assistance of chemometric analysis. We have implemented a scheme which allows a laboratory UV–vis spectrometer to act as a so-called “electronic nose” with very little modification. MgTPP thin films were prepared by a spin coating technique, using chloroform as the solvent, and then subjected to thermal annealing at 280 °C in an argon atmosphere. These MgTPP optical gas sensors presented significant responses with methanol compared to ethanol and isopropanol, based on the dynamic flow of alcohol vapours at the same mol% of alcohol concentration. Density functional theory (DFT) calculations were performed to model the underlying mechanism of this selectivity. The performance of the optical gas sensors was optimised by varying the fabrication parameters. It is hoped that the MgTPP thin film together with an off-the-shelf optical spectrometer and a simple chemometrics algorithm can be a valuable tool for the analysis of alcoholic content in the beverage industry.     

Optical sensor for hydrogen peroxide

Three types of sensors for continuous determination of hydrogen peroxide (HP) are described. The working principles are based on the decomposition of HP by a catalyst and on the measurement of the amount of oxygen thereby produced. The change in oxygen tension is quantitatively determined via the quenching of the fluorescence of a silica gel-adsorbed dye entrapped in silicone rubber. Three methods were found to be useful for HP decomposition. In the first one, the enzyme catalase (which acts as the catalyst) is co-adsorbed onto silica gel and thus is in the same phase as the indicator. In the second one, the enzyme and the dye are adsorbed on different silica gel particles which then are incorporated into the polymer layer. In the third one, finely dispersed silver powder (another catalyst) is embedded in a silicone rubber layer that is spread over the oxygen sensing membrane. The sensor is capable of continuously recording HP in the 0.1 to 10.0 mM concentration range, with a precision of ±0.1 mM at 1 mM HP. Its response time varies from 2.5 to 5 min.     

A Dual Colorimetric and Fluorometric Sensor for Lead Ion Based on Conjugated Polydiacetylenes

A PDA based sensor, derived from a di‐(2‐picolyl) amine (DPA) substituted diacetylene monomer, displayed a selective colorimetric change and a large fluorescence enhancement in the presence of lead ions. The lead selective PDA‐based chemosensor enabled easy detection of the presence of lead in 100% aqueous solution by the naked‐eye.

     

Optical Chemical Sensors Based on Sol-Gel Materials: Recent Advances and Critical Issues

The use of the sol-gel process to produce materials for optical chemical sensors and biosensors is attracting considerable interest. This interest derives mainly from the design flexibility of the sol-gel process and the ease of fabrication. In most applications the sol-gel material is used to provide a microporous support matrix in which analyte-sensitive species are entrapped and into which smaller analyte molecules may diffuse. Sensors based on entrapped organic and inorganic dyes, enzymes and other biomolecules have been reported. A range of sensor configurations has been employed, including monoliths, thin films, as well as more elaborate structures. In this paper a selection is presented of recent significant developments in optical chemical sensors which employ solgel-derived materials. These developments include the tailoring of sol-gel materials to optimise sensor response, advanced waveguide structures and novel probe-tip sensors. Those issues which remain critical to the eventual deployment of sol-gel sensors are examined. In particular, the problems of leaching, microstructural stability, diffusion-limited response time, and susceptibility to interferents are discussed and some solutions proposed.     

A new sensing material for optical oxygen measurement,with the indicator embedded in an aqueous phase

A new type of oxygen-sensitive material is obtained by preparing an aqueous emulsion of a solution of an oxygen-sensitive fluorescent dye in a rigid polymer. The fluorescence of this emulsion is related to the oxygen partial pressure, but a Stern-Volmer plot is not linear over the whole pressure range. Aside from high sensitivity and specificity for oxygen, this new type of sensing material has favorable analytical wavelengths allowing the use of low-cost opto-electronic equipment. Since the indicator is embedded in an aqueous environment, the sensor should be capable of monitoring various kinds of reactions occurring in the aqueous phase, for instance enzymatic reactions which are accompanied by production or consumption of oxygen.     

Chemical sensors (review)

The capabilities and development prospects of chemical sensors as a new area in analytical chemistry and instrument engineering are discussed. Problems of terminology, principles of operation, basic characteristics, and also applications of chemical sensors and sensor analyzers made from them are discussed.From the materials of a report given at a joint scientific session of the departments of the physicochemistry and technology of inorganic materials and of general and technical chemistry.V. I. Vernadskii Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Moscow 117975. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 3, pp. 487–493, March, 1992.     

MOFs传感器在癌症及其生物标志物检测中的应用

癌症是世界上最致命的疾病之一,因此癌细胞的有效捕获和敏感检测对基础研究以及临床诊断和治疗都具有重要意义。基于金属有机骨架(MOFs)的催化活性和固有的发光性能等特点,MOFs已被成功地开发为传感平台实现对癌症及其标志物的检测。综述了基于MOFs的电化学、荧光、电化学发光、比色传感器在癌细胞及核酸、蛋白质等生物标志物检测中近3年的研究进展,从MOFs材料,检测物类型,检测方法、检测能力等方面进行了综述,并对各自的特点进行了讨论,对以后MOFs纳米材料在癌症检测中的应用进行了展望。     

Nitrogen‐doped Hollow Co3O4 Nanofibers for both Solid‐state pH Sensing and Improved Non‐enzymatic Glucose Sensing

Nitrogen‐doped hollow cobalt oxide nanofibers (Co₃O₄ NFs) with both glucose catalytic activity and pH sensitivity were fabricated through core‐sheath electrospinning technique, followed by calcination. The as‐developed nitrogen‐doped hollow Co₃O₄ NFs were thoroughly characterized using various techniques, and then employed to fabricate a dual electrochemical sensor for both pH sensing and glucose sensing. The pH sensitivity of the developed nitrogen‐doped hollow Co₃O₄ NFs demonstrated a Nernst constant of 12.9–15.9 mV/pH in the pH range of 3.0～9.0 and 6.8–10.7 mV/pH in the pH range of 9.0～13.0, respectively. The developed hollow cobalt oxides nanofibers sensor also possesses glucose sensitivity of 87.67 μA mM^?1 cm^?2, the limit of detection of 0.38 μM (S/N=3), and an acceptable selectivity against several common interferents in non‐enzymatic glucose determination. High accuracy for monitoring glucose in human serum sample was also demonstrated. These features indicate that the as‐synthesized nitrogen‐doped hollow cobalt oxides nanofibers hold great potential in the development of a unique dual sensor for both solid‐state pH sensing and superior non‐enzymatic glucose sensing.     

催化发光的应用研究进展

催化发光是物质在催化材料表面发生反应产生的发光现象,是一种重要的化学分析方法,在药物分析、食品分析、免疫学分析以及环境监测等方面具有广泛的应用前景。 本文从挥发性有机物的快速定量检测,分析物的识别区分以及催化剂的活性评估三方面综述了催化发光的应用研究进展,并对催化发光的研究方向进行了展望。     

A Multistep Enzyme Sensor for Sucrose Based on S-Layer Microparticles As Immobilization Matrix

Abstract

In this paper we report on the construction principle and performance of an amperometric 3-enzyme sensor for sucrose based on crystalline bacterial cell surface layers (S-layers) as immobilization matrix for the biological components.

Isoporous, crystalline surface layers (S-layers) have been identified as outermost cell envelope layer in many bacteria. Since they are composed of identical protein or glycoprotein subunits with functional groups in well defined positions and orientations, they represent ideal matrices for the controlled and reproducible immobilization of functional macromolecules, as required for the development of biosensors. Apart from single enzyme sensors, which were described earlier, a strikingly simple method for the assembly and optimization of multistep systems was developed. For the fabrication of an amperometric sucrose sensor invertase, mutarotase and glucose oxidase were individually immobilized on S-layer fragments isolated from Clostridium thermohydrosulfuricum L111-69 via aspartic acid as spacer molecules. Subsequently, appropriate mixtures of enzyme loaded S-layer fragments were deposited on a microfiltration membrane and finally, the composite multifunctional sensing layer was sputtered with gold in order to establish a good metal contact. Amperometric sucrose measurements based on H₂O₂ oxidation revealed a high signal level (1 μA^?1/cm^2?mmol sucrose), 5 min response time and a linear range up to 30 mM sucrose as the main characteristics of the S-layer sucrose sensor.