基于局域表面等离子体共振效应的光学生物传感器*

贵金属纳米粒子表现出许多常规块体材料所不具备的优异性能,其中局域表面等离子体共振 (LSPR) 特性是研究热点之一。LSPR 的形状和位置与纳米粒子的组成、大小、形状、介电性质以及局域介质环境密切相关。基于这一特性,贵金属纳米粒子已广泛应用于光学生物传感器、光过滤器和表面增强光谱等领域。本文对各种结构的贵金属纳米粒子的制备方法及其在光学生物传感器中的应用进行了综述,并对 LSPR 纳米传感器的未来发展前景做了展望。     

贵金属纳米粒子修饰碳纳米管的研究

碳纳米管具有独特的一维管状结构和优异的电、光、热和力学性能,是药物和纳米催化剂的理想载体。将具有独特光、电、磁和催化性能的贵金属纳米粒子负载在碳纳米管的表面,形成的碳纳米管/贵金属纳米粒子复合物不仅兼有两种纳米材料的优异性能,还可能产生新的特性,在催化、储能、燃料电池、电子器件和传感器等领域均有广阔的应用前景。本文主要从共价修饰和非共价修饰两种策略出发,综述了贵金属纳米粒子修饰碳纳米管的制备方法和研究进展。其中用天然高分子包覆的碳纳米管表面具有很好的贵金属配位结合能力,得到的纳米复合物具有良好的水分散性和生物相容性,在载药、生物传感器和肿瘤诊断治疗等生物领域具有明显的优势。     

贵金属复合纳米粒子的研究进展

贵金属复合纳米粒子具有不同于单组分纳米粒子的独特的光、电和催化等物理与化学性能,是构筑新型功能复合材料的重要单元,在传感器、光学材料、催化剂及生物领域都有着重要应用,已成为当前纳米材料科学研究领域中的前沿和热点。本文主要评述了具有核壳、异质结构以及合金结构的贵金属复合纳米粒子的制备、物理与化学性能及应用等方面的研究进展。     

纳米金-生物酶膜在葡萄糖生物传感器上的应用

把金纳米颗粒加入到生物酶膜中制备葡萄糖生物传感器,分析了电极的反应机理和金纳米颗粒对电极电流响应的影响,并进行了电极的性能测定。试验表明,引入金纳米粒子可显著提高电极的响应灵敏度．制备的传感器抗干扰性强,稳定性高,成本较低,操作简便.     

多肽在贵金属纳米粒子制备中的应用

由于具有与大块固体相迥异的性能,贵金属纳米粒子的制备与应用已经成为当前纳米、材料技术领域研究的热点。由于组成成分较多、包含各种活性基团、序列可调,并且很多多肽可生物降解、生物兼容、具有生物活性和特异性识别性能,多肽在贵金属纳米粒子制备中的应用也越来越受到人们的重视。本文从多肽作为还原剂还原贵金属盐; 多肽作为保护剂/调控剂制备不同尺寸/形貌的贵金属纳米粒子; 多肽作为引导剂规则排列贵金属纳米粒子; 多肽作为贵金属纳米粒子组装的模板以及多肽在贵金属表面的吸附、多肽的自组装和如何获取所需要的多肽序列等几个方面综述了近年来多肽在贵金属纳米粒子制备中的应用。最后简述了利用多肽制备的贵金属纳米粒子在纳米、材料技术领域中的应用,并提出了当前该领域中存在的一些不足及研究展望。     

生物法制备各向异性贵金属纳米粒子的研究进展

利用生物法绿色合成各向异性的贵金属纳米粒子(Au,Ag)具有经济环保、制备简单、无毒副作用等优点,成为近年来的研究热点。 本文通过介绍各向异性贵金属纳米粒子的物理化学性质,归纳了生物法,尤其是利用植物源生物质制备各向异性贵金属纳米粒子的研究,并在此基础上进一步阐述了各向异性贵金属纳米粒子的微观生长机理,最后对各向异性贵金属纳米粒子的应用前景做了展望。     

纳米结构聚吡咯构建的生物传感器

本文总结了纳米结构聚吡咯对生物分子的固定方法如吸附法、电化学聚合包埋法、共价键偶联法以及分子印迹法,重点评述了基于纳米结构聚吡咯的电流型生物传感器,如酶、核酸、免疫传感器等的工作原理和探测性能.指出聚吡咯纳米敏感材料优良的选择透过性和高比表面积有利于生物分子的固定,提高了生物传感器的敏感度;聚吡咯良好的生物相容性和抗干扰性,可以很好地保持生物分子的活性,提高生物传感器的选择性和环境稳定性;聚吡咯与其它敏感材料如碳纳米管或金属纳米粒子复合,两者的协同效应使电极的电化学信号放大、电催化活性可提高2～4个数量级.检出限最高可提升5万倍;聚吡咯纳米生物传感器在生物医学工程、临床诊断、环境监测、食品卫生和科学等领域展现出广阔的应用前景.     

暗场显微镜下的彩色“纳米星”（英文）

具有独特局域表面等离子共振散射特性的贵金属纳米粒子,在可见光区域表现出明显的吸收和散射光谱特性。在过去的几十年中,基于纳米金和纳米银溶液的可视化颜色传感器,被广泛应用在金属离子、生物分子、农药等灵敏检测。自2000年,暗场显微镜的出现,实现了纳米尺度下等离子共振散射光谱的精准获取,将传感尺度从传统的实验试管发展到单纳米颗粒界面。单颗粒检测消除了本体溶液中大量纳米粒子产生的平均效应,可提供更加准确的反应信息。纳米粒子的散射光谱主要取决于颗粒的尺寸、形貌、成分以及颗粒间耦合作用等,因此,具有特定散射颜色的单个纳米粒子,可以作为优异的纳米探针。这篇综述聚焦于单颗粒纳米传感,首先介绍了纳米粒子局域表面等离子共振的原理和发展历史。随后,主要讨论了单个贵金属纳米粒子作为颜色编码传感器,在生物分子、环境污染物以及能源等领域的应用,尤其是基于单颗粒的原位纳米光谱电化学传感及其在电催化反应中的应用。例如,利用纳米粒子的溶出和生长过程,精巧地设计了针对不同待测物的纳米探针。另一方面,对单纳米粒子结构演变过程的原位监测,也有助于对纳米材料制备机理的理解。最后,着重探讨了纳米颜色传感器信号提取放大的检测手段,...     

基于贵金属纳米颗粒生长的比色传感研究进展

近年来,作为颜色标记和信号发生器的贵金属纳米粒子由于其简单性和实用性而被广泛用于比色测定和传感的研究当中。本文综述了近十年基于贵金属纳米粒子生长的比色传感器策略和应用的最新进展,总结了基于贵金属纳米颗粒生长的单色及多色传感器的传感原理、分类及前沿应用,探索了其比色传感的信号产生、分类和放大机制。由于贵金属纳米粒子在不同尺寸、距离、形状、成分等基底上的生长会产生不同的LSPR共振峰以及显著的传感信号变化,我们详细讨论了贵金属纳米粒子在金纳米棒等晶种基底上生长的比色传感。最后,我们对目前该比色传感面临的挑战和未来前景进行了展望。     

贵金属纳米粒子与水凝胶复合材料的制备及其在分析化学领域的应用进展

贵金属纳米材料由于其独特的光电化学性能,在分析化学领域应用广泛.但是,纳米粒子在水溶液中不稳定,这在一定程度上限制了贵金属纳米材料的发展,水凝胶载体能够很好地解决此问题.水凝胶具有优异的机械性能、良好的生物相容性和易于改性等特点,在稳定纳米材料的同时,能够提升纳米材料的性质,因此,贵金属纳米粒子与水凝胶复合材料的研究逐...     

Enzymatic biosensors based on the use of metal oxide nanoparticles

Over the past decades, various techniques have been developed to obtain materials at a nanoscale level to design biosensors with high sensitivity, selectivity and efficiency. Metal oxide nanoparticles (MONPs) are of particular interests and have received much attention because of their unique physical, chemical and catalytic properties. This review summarizes the progress made in enzymatic biosensors based on the use of MONPs. Synthetic methods, strategies for immobilization, and the functions of MONPs in enzymatic biosensing systems are reviewed and discussed. The article is subdivided into sections on enzymatic biosensors based on (a) zinc oxide nanoparticles, (b) titanium oxide nanoparticles, (c) iron oxide nanoparticles, and (d) other metal oxide nanoparticles. While substantial advances have been made in MONPs-based enzymatic biosensors, their applications to real samples still lie ahead because issues such as reproducibility and sensor stability have to be solved. The article contains 256 references.

Mesoporous Bimetallic PtPd Nanoflowers as a Platform to Enhance Electrocatalytic Activity of Acetylcholinesterase for Organophosphate Pesticide Detection

Mesoporous bimetallic PtPd nanoflowers (MPtPdN) were synthesized by a surfactant‐directing method. The MPtPdN was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and wide‐angle X‐ray diffraction (XRD). The use of MPtPdN as a platform for the indirect electrochemical detection of organophosphate pesticides (OPs) via enzymatic inhibition pathway was demonstrated. Due to the nanostructure of MPtPdN and the synergy effect of the noble metal nanoparticles, a novel and sensitive acetylcholinesterase (AChE) biosensor for OPs detections based on MPtPdN and enzyme inhibition was prepared. The inhibition of omethoate exhibited a linear relationship from 4.7×10⁻¹¹ to 4.7×10⁻⁸ M with a detection limit of 1.7×10⁻¹² M (S/N=3). The proposed AChE biosensor was reliable and can be used to measure the concentration of omethoate in different spiked samples with high accuracy and satisfactory recovery. The preparation of biosensors based on the MPtPdN can be further extended to construct many other important enzyme biosensors.     

Optical biosensors based on Prussian Blue films

Optical biosensing schemes based on enzymatically modified inorganic/organic transparent films predominately composed of Prussian Blue are demonstrated. The composite film, which is non-electrochemically deposited on a non-conducting support. is used as an optical transducer for flow-through biosensors based on hydrolases and oxidases. Urease and glucose oxidase are utilized as model enzymes. Action of the urea biosensor is based on optical pH sensitivity of Prussian Blue indicator. The glucose biosensor is acting as first-generation optical biosensor based on in situ generated Prussian White transducer for hydrogen peroxide. These simple, single-pass transmission optical biosensors exhibit sensitivity in the millimolar range of concentration. The biosensors are very stable owing to presence of a poly(pyrrolylbenzoic acid) network in the composite material. This organic polymer plays a dual role as a binding agent for inorganic material and as a functionalized support for strong covalent immobilization of enzyme molecules.     

Bacterial synthesized metal and metal salt nanoparticles in biomedical applications: An up and coming approach

In the present scenario, metal nanoparticles have elicited a great deal of interest in biomedical applications because of their unique properties and antimicrobial potentials. Over the past few years, the green nanotechnology has materialized as a momentous approach for the synthesis and fabrication of noble metal salt and metal nanoparticles. The green route synthesis exploits diverse reducing and stabilizing agents from bacterial resources for the successful synthesis of metal nanoparticles. This review mainly focuses on the biosynthesis of the most commonly studied metal and metal salt nanoparticles such as gold, silver, platinum, palladium, copper, cadmium, titanium oxide, zinc oxide, zinc sulphate, cadmium sulphide and many more. These noble nanoparticles can be exploited in pharmaceutical industry as antimicrobial and anti-biofilm agents, targeted delivery of anticancer drugs, biosensors, etc.     

Analytical Characteristics of Electrochemical Biosensor Using Pt‐Dispersed Graphene on Boron Doped Diamond Electrode

An electrochemical biosensor was developed using Pt‐nanoparticles (Pt‐NPs) dispersed graphene based on a boron‐doped diamond thin film electrode. To compare its performances with those of other biosensors, glucose was used as a target analyte. This biosensor exhibited a wide linear range, a low detection limit and a higher sensitivity compared to other amperometric biosensors using graphene‐based electrodes. In addition, the biosensor promotes a direct electron transfer between the redox enzymes and the electrode surface and detects low concentration analytes. The excellent performance of the biosensor is attributed to the synergistic effect of the Pt‐NPs, graphene sheet and the BDD thin film. Therefore, it can be a promising application for electrochemical detection of analytes.     

Electron donor solvent effects provide biosensing with quantum dots

A palmitate biosensor that uses the emission intensity of a semiconducting nanoparticle to report palmitate concentration is presented. This method uses electron transfer to quench the emission from a ZnS-coated CdSe nanoparticle. The fatty acid binding pocket of intestinal fatty acid binding protein is used to modulate the electron transfer properties of [Ru(L)(NH3)4](PF6)2 (L = 5-maleimido-1,10-phenanthroline) that is covalently attached within this pocket. Once the metal-complex-modified protein is attached to ZnS-coated CdSe nanoparticles, palmitate addition excludes water from around the metal complex and increases the electron transfer from the metal complex to the valence band hole of the nanoparticle excited state. A 1.6-fold change in emission intensity is observed upon adding a saturated amount (500 nM) of sodium palmitate. The dissociation constant was calculated as 5 nM with a 1 nM lower limit of detection. Since palmitate does not alter the global conformation of intestinal fatty acid binding protein, palmitate-mediated changes in pocket solvation are suggested. This represents a new method in biosensor construction with semiconducting nanoparticles. Including previous conformation-dependent biosensors, there are thousands of potential analytes that can be detected with these strategies. Such biosensors will provide fluorescence contrast imaging reagents for small molecule analytes.     

电化学葡萄糖传感器

作为电化学生物传感器中最重要的研究内容之一,葡萄糖生物传感器在数十年的发展中取得了巨大进展。本文综述了近年来利用纳米技术设计的新型电化学葡萄糖传感器的主要研究进展,并从纳米材料维度分类进行了讨论。其中,零维纳米材料主要讨论了包括金纳米颗粒、银纳米颗粒以及铜、铂等金属纳米颗粒材料; 一维纳米材料主要讨论了通过模板法制备的金属或金属氧化物纳米线以及单臂或者多壁纳米管材料; 二维纳米材料主要总结了以碳为基础的石墨烯材料和一些片状的金属材料。纳米材料对电化学葡萄糖传感器的影响主要集中在生物相容性、增强检测灵敏度、酶的固定等方面。此外,本文也对电化学葡萄糖传感器的今后发展做了展望。     

Sensitive Biosensors Based on (Dendrimer Encapsulated Pt Nanoparticles)/Enzyme Multilayers

A sensitive enzymed‐based biosensor for glucose has been obtained by introducing dendrimer encapsulated Pt nanoparticles via a layer‐by‐layer assembling method. The free amine groups located on each poly(amidoamine) dendrimer molecule were exploited to covalently attach enzyme to the dendrimer chains using carbodiimide coupling. The resultant enzyme electrodes are shown to have excellent sensitivity (as high as 30.33 μA mM^?1 cm^?2) and a limit of detection (about 0.1 μmol L^?1), depending on metal nanoparticles within dendrimers and the biocompatibility of dendrimers, the linear response range to glucose (from 5 μM to 1.0 mM), a fast response time (within 5 s), and good reproducibility (<8% relative standard deviation between electrodes at low substrate concentration). The sensitivities, and stabilities determined experimentally have demonstrated the potential of dendrimer encapsulated Pt nanoparticles as a novel candidate for enzymatic glucose biosensors.