多酸-纳米粒子复合物的研究进展

多酸-纳米粒子复合物既具有多酸(POMs)多样的尺寸、可调节的多功能结构、丰富的组成、高的电荷密度及可逆的氧化还原等特性,同时又具有纳米粒子的声、光、电、磁、热、力学等特性.多酸-纳米粒子复合物有望被广泛运用到生物催化、电催化、光催化、生物传感和医药化学等领域.本文作者主要对多酸-纳米粒子复合物的合成方法和应用进行评述,并对今后的发展趋势进行展望.     

基于金纳米粒子的光学生物传感方法研究进展

光学生物传感是以产生各种光学信号为检测基础的一种微量分析技术,具有操作简便、检测成本低、抗干扰能力强及可实现原位检测等优点,在临床诊断、药物分析、环境监测等领域显示出广阔的应用前景.作为纳米材料重要成员之一的金纳米粒子(AuNPs),因其独特的光学性质被广泛用于光学生物传感方法的构建.该文综述了近年来基于金纳米粒子的光...     

硫化金包覆金纳米棒局域等离子体共振的纳米生物传感器研究

纳米生物传感技术是近年来迅速发展起来的一种超微生物传感技术,具有高选择性、高灵敏度、快速、方便检测等优点.尤其基于金纳米颗粒的生物探针的研究备受关注.近年来,对基于棒状金纳米结构的生物探针合成及在生物传感及医学成像中的应用的研究是金纳米棒研究的重要方向.纳米金由于其制备简单、易于修饰、稳定性和生物相容性好等优点,被广泛应用于生物分子的识别和检测领域.     

聚二甲基硅氧烷-纳米金复合材料的制备与生物传感应用

作为一种新型复合材料,聚二甲基硅氧烷-纳米金复合材料兼具聚二甲基硅氧烷和纳米金的良好导电性、生物亲和性及超疏水性等优点,广泛用于生物传感、生物功能材料、环境保护、微流控等领域.该文评述了常规实验室制备聚二甲基硅氧烷-纳米金复合材料的两种主要方法及其在生物传感领域中的应用,并对聚二甲基硅氧烷-纳米金复合材料的发展趋势和应...     

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。     

几种常见纳米材料构建的光学传感体系在生化分析中的应用

近年来生物传感新体系的出现,极大地推动了生物医学、分析、环境等研究领域的发展.由于纳米材料具有一些独特的理化性质,常作为载体材料、信号分子等被广泛应用于构建光学生物传感体系.主要介绍了基于金纳米粒子、石墨烯、碳纳米管、量子点、硅纳米粒子几种常见纳米材料构建的光学传感体系及其在生化分析中的应用.分析讨论了这些体系的原理和实际应用,并展望了其研究和应用前景.     

聚合物-纳米金在油水界面的自组装及有序结构的构筑

聚合物-纳米金复合物既具有金纳米粒子的光、电及催化性能,又具有聚合物的可加工性及对外界的刺激响应性,因此已成为高分子科学及材料科学研究的热点。本文主要介绍了我们实验室在聚合物-纳米金在油水界面的自组装及有序结构的构筑研究方面的相关工作:(1)利用界面聚合的方法制备侧链接枝亲水性金纳米粒子的聚苯乙烯及杂化聚合物在水溶液中的自组装;(2)亲水性金纳米粒子及疏水性聚合物(或疏水性磁性纳米粒子)在油水界面的自组装研究;(3)利用金纳米粒子为交联点制备具有温度响应性聚合物微凝胶的研究。     

金纳米粒子的表面修饰及生物应用进展

近年来纳米材料被广泛应用于生物医学、航空航天和精细化工等领域。构成纳米材料的纳米粒子具有小尺寸效应、表面效应和宏观量子隧道效应等性质。其中金纳米粒子由于其独特的荧光特性、良好的生物相容性和表面等离子共振等性质,被广大科研人员进行深入研究。例如,在生物医学领域,科研人员构建了一系列新型的金纳米比色传感器、光学探针及各类载药体系等。然而,目前金纳米粒子仍存在水分散性差、肾清除效率低和量子发射产率低等问题,限制了其广泛应用。因此,研究人员对金纳米粒子表面进行多样化修饰,从而能有效克服上述缺点。本文就目前主流配体表面修饰金纳米粒子的研究进展进行了详细总结,着重介绍了功能化金纳米粒子在生物成像、生物检测、生物治疗三方面的应用,最后对金纳米粒子的临床治疗机制的探索以及商业化的应用进行了展望,希望能为相关领域的研究者们提供新思路。     

高保真纳米耀斑在生物传感中的应用

传统的纳米耀斑是基于金纳米颗粒（Au NPs）通过金-硫（Au-S）键共价组装功能核酸而成,广泛应用于DNA可编程组装、生物传感、成像和治疗等领域。然而,在细胞环境中,生物硫醇和其他化学物质的干扰是一个长期存在的问题,阻碍了其实际应用。针对此问题,通过升级纳米耀斑实现细胞内的高保真荧光成像,避免生物硫醇和其他化学物质的干扰以获得高保真信号,对细胞内高精度成像具有重要意义。本文对高保真纳米耀斑相关研究进行了归纳整理,系统概述了高保真纳米耀斑的设计原理及其在生物传感中的应用,最后展望了该策略在细胞成像方面的优势及应用前景。     

金纳米粒子和聚合物复合体系分子设计与组装过程的计算机模拟

金纳米粒子除了拥有纳米粒子的体积效应、表面效应、量子尺寸效应、宏观量子隧道效应等优异性能之外,还有一些特殊性能,如良好的稳定性、抗菌抑菌功能、表面吸收带效应、荧光效应等。量子化学计算方法提供了从分子水平上探究金团簇的催化和反应活性的影响因素,如金团簇的尺寸、形状、电子状态、活性位点的类型和结构等。分子动力学可以更好地模拟纳米粒子与配体和溶剂的相互作用方式,同时给出热力学和动力学行为。耗散粒子动力学等介观模拟方法则被应用到金纳米粒子和聚合物复合体系自组装过程的研究,并可以给出调控自组装结构的有效方案。以高分子与纳米粒子复合物为研究对象,明晰影响复合物结构和性质的主导因素,探索复合物调控机制,提出决定复合物功能的主控因素,进一步理解高分子与纳米粒子复合物的本质,可以为实验上制备、优化新型高分子与纳米粒子复合物材料提供可靠的理论帮助。     

New nanostructured electrochemical biosensors based on three-dimensional (3-mercaptopropyl)-trimethoxysilane network

The design and characterization of a new nanostructured organic-inorganic hybrid material and its application to L-lactic acid determination are described. This material is based on the integration of the enzyme lactate oxidase (LOx) and gold nanoparticles (AuNPs) into a sol-gel 3D polymeric network derived from (3-mercaptopropyl)-trimethoxysilane (MPTS) previously formed onto a gold surface. MPTS presents the advantage of forming a 3D polymeric network containing a large number of thiol tail groups distributed throughout its structure that enable both its anchoring onto gold surfaces and the AuNPs incorporation. Moreover, this matrix provides a biocompatible environment that preserves the catalytic activity of LOx after its immobilization and allows the incorporation of a high amount of enzyme, which is expected to improve the sensitivity of the final biosensing device. Characterization of the designed biosensing platform was performed using quartz crystal microbalance (QCM), scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques. From the conjunction of these techniques, information about (i) the kinetic of LOx adsorption process in real time, (ii) the amount of LOx incorporated into the network, and (iii) the morphological characteristics at the nanometre level of the designed biosensing material was obtained. This information is very useful on the development of successful biosensing devices. Finally, the response of the biosensor to L-lactic acid was evaluated. The biosensor responds linearly to L-lactic acid in the range of 50 μM to 0.25 mM, with a sensitivity of 3.4 μA mM(-1) and a detection limit of 4.0 μM.     

Recent progress in gold nanoparticle-based biosensing and cellular imaging

Gold nanoparticles (AuNPs) have been extensively used in optical biosensing and bioimaging due to the unique optical properties. Biological applications including biosensing and cellular imaging based on optical properties of AuNPs will be reviewed in the paper. The content will focus on detection principles, advantages and challenges of these approaches as well as recent advances in this field.     

Preparation of gold nanoparticles on eggshell membrane and their biosensing application

A facile green biosynthesis method has been successfully developed to prepare gold nanoparticles (AuNPs) of various core sizes (25 ± 7 nm) using a natural biomaterial, eggshell membrane (ESM) at ambient conditions. In situ synthesis of AuNPs-immobilized ESM is conducted in a simple manner by immersing ESM in a pH 6.0 aqueous solution of HAuCl₄ without adding any reductant. The formation of AuNPs on ESM protein fibers is attributed to the reduction of Au(III) ions to Au(0) by the aldehyde moieties of the natural ESM fibers. Energy dispersive X-ray spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, and X-ray powder diffraction unambiguously identify the presence of AuNPs on ESM. The effect of pH on the in situ synthesis of AuNPs on ESM has been investigated in detail. The pH of the gold precursor (HAuCl₄) solution can influence the formation rate, dispersion and size of AuNPs on ESM. At pH ≤3.0 and ≥7.0, no AuNPs are observed on ESM while small AuNPs are homogeneously dispersed on ESM at pH 4.0-6.0. The optimal pH for AuNPs formation on ESM is 6.0. AuNPs/ESMs are used to immobilize glucose oxidase (GO_x) for glucose biosensing. AuNPs on ESM can increase the enzyme activity of GO_x. The linear response range of the glucose biosensor is 20 μM to 0.80 mM glucose with a detection limit of 17 μM (S/N = 3). The biosensor has been successfully applied to determine the glucose content in commercial glucose injections. Our work provides a very simple, non-toxic, convenient, and green route to synthesize AuNPs on ESM which is potentially useful in the biosensing field.     

Coupling a universal DNA circuit with graphene sheets/polyaniline/AuNPs nanocomposites for the detection of BCR/ABL fusion gene

This article described a novel method by coupling a universal DNA circuit with graphene sheets/polyaniline/AuNPs nanocomposites (GS/PANI/AuNPs) for highly sensitive and specific detection of BCR/ABL fusion gene (bcr/abl) in chronic myeloid leukemia (CML). DNA circuit known as catalyzed hairpin assembly (CHA) is enzyme-free and can be simply operated to achieve exponential amplification, which has been widely employed in biosensing. However, application of CHA has been hindered by the need of specially redesigned sequences for each single-stranded DNA input. Herein, a transducer hairpin (HP) was designed to obtain a universal DNA circuit with favorable signal-to-background ratio. To further improve signal amplification, GS/PANI/AuNPs with excellent conductivity and enlarged effective area were introduced into this DNA circuit. Consequently, by combining the advantages of CHA and GS/PANI/AuNPs, bcr/abl could be detected in a linear range from 10 pM to 20 nM with a detection limit of 1.05 pM. Moreover, this protocol showed excellent specificity, good stability and was successfully applied for the detection of real sample, which demonstrated its great potential in clinical application.     

“Signal-on” Electrogenerated Chemiluminescence Biosensing Method for the Determination of Matrix Metalloproteinase 2

A simple, selective and sensitive “signal-on” electrogenerated chemiluminescence (ECL) biosensing method was developed for matrix metalloproteinase 2 (MMP-2). Ru(bpy)₃²⁺, gold nanoparticles (AuNPs) and Nafion were modified onto glassy carbon electrode (GCE) to form Ru(bpy)₃²⁺/AuNPs/Nafion/GCE as sensitive ECL platform and then ferrocene (Fc) labeled peptide was assembled onto the modified electrode to form ECL biosensing platform. The ECL intensity increased when the ECL biosensing electrode reacted with MMP-2 because of MMP-2-induced cleavage of Fc labeled peptide. The ECL method was applied to determine MMP-2 with detection limit of 0.3 ng/mL and one-step recognition, which is promising for point-of-care test of protease.     

Nanoparticle based enhancement of electrochemical DNA hybridization signal using nanoporous electrodes

A novel nanoparticle-based enhanced methodology for the detection of ssDNA using nanoporous alumina filter membranes, containing pores of 200 nm in diameter, is reported. The blockage of the pores due to the hybridization is detected by measuring the decrease in the differential pulse voltammetric response of the [Fe(CN)(6)](4-/3-) redox indicator and using screen-printed carbon electrodes as transducing platform. Furthermore, 20 nm gold nanoparticle (AuNPs) tags are used in order to increase the sensitivity of the assay. The enhancement mechanism of DNA detection is due to an additional blocking effect induced by hybridization reaction by bringing AuNPs inside the pores. The developed methodology can be extended to other biosensing systems with interest not only for DNA but also for proteins and cells. The developed nanochannel/nanoparticle biosensing system would have enormous potential in future miniaturized designs adapted to mass production technologies such as screen-printing technology.     

Continuous Electroformation of Gold Nanoparticles in Nanoliter Droplet Reactors

Gold nanoparticles (AuNPs) are employed in numerous applications, including optics, biosensing and catalysis. Here, we demonstrate the stabilizer-free electrochemical synthesis of AuNPs inside nanoliter-sized reactors. Droplets encapsulating a gold precursor are formed on a microfluidic device and exposed to an electrical current by guiding them through a pair of electrodes. We exploit the naturally occurring recirculation flows inside confined droplets (moving in rectangular microchannels) to prevent the aggregation of nanoparticles after nucleation. Therefore, AuNPs with sizes in the range of 30 to 100 nm were produced without the need of additional capping agents. The average particle size is defined by the precursor concentration and droplet velocity, while the charge dose given by the electric field strength has a minor effect. This method opens the way to fine-tune the electrochemical production of gold nanoparticles, and we believe it is a versatile method for the formation of other metal nanoparticles.     

酶法合成的葡萄糖氧化酶-纳米金复合物的直接电化学与生物传感

将NaAuCl₄、葡萄糖氧化酶（GOx）和葡萄糖混合,借一步酶促反应制得吸附GOx的金纳米颗粒（AuNPs）,再通过滴干修饰法研制了Nafion/GOx-AuNPs修饰的玻碳（GC）电极,并考察了该酶电极上GOx的直接电化学和生物传感性能. 这种酶法合成的GOx-AuNPs复合物有良好的酶直接电化学活性,也保持了GOx的生物活性,似可归因于酶法合成的纳米金更接近酶氧化还原活性中心的缘故. 该酶电极在-0.4 V（vs. SCE）电位下,其稳态电流下降与葡萄糖浓度（0.5 4 mmol·L^-1）成正比,检测下限0.2 mol·L^-1.     

CHCA-modified Au nanoparticles for laser desorption ionization mass spectrometric analysis of peptides

Gold nanoparticles (AuNPs) have been studied as a potential solid-state matrix for laser desorption/ionization mass spectrometry (LDI-MS) but the efficiency in ionization remains low. In this report, AuNPs are capped by a self-assembled monolayer of cysteamine and modified with α-cyano-4-hydroxycinnanic acid (CHCA) for effective MALDI measurements. CHCA-terminated AuNPs offer marked improvement on peptide ionization compared with citrate-capped or cysteamine-capped AuNPs. The coating also effectively suppresses formation of Au cluster ions and analyte fragment ions, leading to cleaner mass spectra. Addition of glycerol and citric acid to the peptide/AuNPs sample further improves the performance of these AuNPs for LDI-MS analysis. Glycerol appears to enhance the dispersion of AuNPs in sample spots, increasing the sample ionization and shot-to-shot reproducibility, while citric acid serves as an external proton donor, providing high production of protonated analyte ions and reducing fragmentation of peptides on the nanoparticle-based surface. Optimal ratios of citric acid, glycerol, and AuNPs in sample solution have been systematically studied. A more than 10-fold increase for desorption ionization of peptides can be achieved by combining 5% glycerol and 20 mM citric acid with the CHCA-terminated AuNPs. The applicability of the CHCA-AuNPs for LDI-MS analysis of protein digests has also been demonstrated. This work shows the potential of AuNPs for SALDI-MS analysis, and the improvement with chemical functionalization, controlled dispersion, and use of an effective proton donor.     

Interaction of peptides with graphene oxide and its application for real-time monitoring of protease activity

We have developed a novel graphene-based biosensing platform using peptides as probe biomolecules, and demonstrated its feasibility in the application of real-time monitoring of protease activity based on FRET between GO and dye-labeled peptides. This assay allows the rapid and accurate determination of enzyme kinetic parameters as well as inhibition constants.