梨醋半成品的超滤处理

用截留分子量不同的中空纤维超滤膜组件对梨醋半成品进行了处理.结果表明,使用截留分子量为1万的中空纤维超滤膜组件,在0.1 MPa压力差和室温下,将梨醋半成品超滤5 h,透过通量基本恒定在6 L/(m2.h).梨醋经过超滤,酸度保留率可达97.4%,糖度保留率88.3%,且风味不变,澄清透明,放置13个月无沉淀物.     

糖芯片合成中的固定化策略*

近年来,糖芯片作为一种强有力的生化分析工具在糖生物学的研究中获得了越来越广泛的应用。在糖芯片制备过程中,糖探针在基板表面的固定是最重要也是最难的一步,它不仅要能牢固的固定在芯片基板上,还必须具有足够的生物活性,因此糖芯片在制备过程中制定合适的糖探针固定化策略一直是一个难点,也是极具挑战性的研究热点。本文首先概述了近几年糖芯片作为一种强有力的生化分析工具在糖生物学研究中的应用。详尽介绍了三种将糖探针固定在固相基片表面的策略：（1）非位点特异性、非共价的方式;（2）位点特异性、非共价的方式;（3）位点特异性、共价的方式。并对糖芯片固定化策略的发展进行了展望。     

一体化微流控芯片的酶固定化技术

20世纪90年代,Manz等提出的微全分析系统越来越受到关注,聚二甲基硅氧烷[Poly(dimethylsiloxane),PDMS]材料具有透光性能好和绝缘等优点,并可通过浇铸法制作一体化的芯片,从而有效地解决芯片的封合问题。     

固定化微生物处理垃圾渗滤液

重点研究了固定化微生物处理垃圾渗滤液时的处理结果以及主要性能．通过对进水与出水COD及氨氮等指标进行检测分析,研究了固定化微生物对COD和氨氮的高效去除效果．并采用GC—MS对处理前后的垃圾渗滤液组分进行定性分析,同时利用Kjeldahl’s法测定了高效微生物菌群在载体上的生物负载量,最后采用电子显微镜观察了固定化微生物的形态．研究结果表明：采用固定化微生物处理渗滤液,COD和氨氮去除率分别达到98．3％和99．9％．处理后的垃圾渗滤液组分中有机物大量减少,生物负载量为38g·L^-1,丝状微生物较为发达．而且200mg·L^-1以上的氨氮以及150mg·L^-1以上的NH3对硝化菌及亚硝化菌没有抑制作用．在有机负荷较高的情况下,固定化微生物仍具有较好的硝化作用．还在相同条件下与游离微生物性能进行了比较,说明固定化微生物技术在各个方面所表现出的性能较后者具有明显的优势．     

酶的树脂法固定化及其应用

简述了酶的树脂法固定化方法及所用树脂,列举了固定化、分离提纯及应用实例。     

以醋酸纤维素吸水胶囊为载体制备固定化脲酶

把高吸水材料封在具超滤功能的醋酸纤维素（CA）皮膜中，制成胶囊。此胶囊浸泡在脲酶水溶液中，水分受高吸水材料的吸引透过皮膜进入胶囊中，脲酶被截留在CA皮膜上，并且与CA上的活性基团相结合，形成CA胶囊固定化脲酶。     

固定化酶反应器及其在蛋白质组研究中的应用

综述了近年来国内外酶固定化载体的研究进展,侧重于无机材料和有机聚合物材料上的固定化酶方法;此外,也介绍了固定化胰蛋白酶反应器与分离系统联用在蛋白质样品分析中的应用,并展望了固定化酶反应器的研究方向及其在蛋白质组中的应用前景。     

酶的固定化及其应用

酶的固定化研究始于1960年代中期,从1970年代初开始酶的固定化技术研究发展很快,至1980年代初,每年约发表1000篇以上的文献和近200篇专利,所报道的固定化方法达100种以上[1].1980年代中以后,酶和细胞固定化研究的发展速度开始减慢,从而有人认为,对酶的固定化技术应予以重新评价     

基于DNA定向固定化技术构建毛细管固定化酶微反应器的研究进展

生物酶影响着物质代谢和质能转换等生命活动,生物体内某些酶的活性变化会导致疾病的发生。发展新型的酶分析方法对深刻理解生物代谢过程、疾病诊断和药物研发等具有重要意义。毛细管电泳(CE)具有分离效率高、分析速度快、操作简单和样品消耗少以及可与多种检测手段联用等优点,在酶分析研究中越来越受到关注。CE酶分析主要包括离线和在线两种模式,其中,固定化酶微反应器与毛细管电泳联用(CE-IMER)的在线酶分析已经成为主要的酶分析方法之一。CE-IMER充分结合了固定化酶和CE的优势,将游离酶固定在毛细管内,不仅可以显著提高酶的稳定性和重复使用性,而且可以实现纳升规模溶液的自动化酶分析,进而显著降低酶分析成本。目前已有大量方法制备IMER用于CE酶分析,然而如何构建性能良好、可再生使用、酶固载量大、自动化程度高的CE-IMER一直是该领域重点研究的问题。DNA定向固定化技术(DDI)可以充分利用DNA分子的碱基互补配对(A-T, C-G),在温和的生理条件下特异性固定生物大分子。由于短链双螺旋DNA分子具有较强的机械刚性和物理化学稳定性,通过DDI将酶固定在载体表面,有利于降低传质阻力,提高酶与底物的接...     

肽配基纳米亲和载体定向固定化抗体

抗体经常被固定在某一固相载体表面用于免疫检测分析,但通常得到的是随机固定化的抗体,因而会影响抗体的活性。本文开发了一种新型的亲和载体用于抗体的定向固定化。即将与抗体IgG的Fc片段具有亲和作用的肽配基偶联于pGMA纳米球上,制备亲和载体用于吸附抗体实现抗体的定向固定化。首先利用乳液聚合法制备了粒径为110nm的pGMA纳米球,再以EDMA为交联剂并且在纳米球表面氨基化,最后将与抗体IgG的Fc片段具有亲和作用的肽配基HWRGWV偶联于纳米球表面,制备得到肽配基纳米球亲和载体。然后,考察了亲和载体对猪IgG的吸附行为。进一步,利用等温滴定微量量热仪研究了该纳米球亲和载体与IgG之间的相互作用热力学。结果表明,肽配基亲和载体对IgG的特异性吸附作用明显高于肽配基修饰前的载体。亲和载体与IgG的亲和作用主要贡献是疏水相互作用;而IgG与氨化纳米球载体的吸附作用则主要通过静电作用和氢键作用。所制得的纳米球亲和载体可用于进一步开发高效率、高灵敏度的临床免疫检测方法。     

Comparative Assessment of Oriented Antibody Immobilization on Surface Plasmon Resonance Biosensing

Protein A and protein G are extremely useful molecules for the immobilization of antibodies. However, there are limited comparative reports available to evaluate their immobilization performance for use as biosensors. In this study, a comparative analysis was made of approaches that use protein A and protein G for avian leukosis virus detection. The antibody‐protein binding affinities were determined using surface plasmon resonance (SPR) analysis. The immobilization efficiency was obtained by calculating the number of the protein molecular binding sites. The positive influence of sensor response on antigen detection indicates that the amount of immobilized antibody plays a major role in the extent of immobilization. Moreover, the biosensors constructed using both proteins were found to be regenerative. The SPR results from this study suggest that the surfaces of protein G provide a better equilibrium constant and binding efficacy for immobilized antibodies, resulting in enhanced antigen detection.     

Anti-T2 Monoclonal Antibody Immobilization On Quartz Fibers: Stability and Recognition of T2 Mycotoxin

Abstract

Several methods for immobilizing anti-T2 mycotoxin monoclonal antibodies on quartz fibers, for use in optical sensor development, have been evaluated with respect to the surface density and stability of the immobilized proteins. the first method activates matrix hydroxyl groups using p-toluenesulfonyl chloride (TSC). the second method activates these groups using p-nitrophenyl chloroformate (NPCF). the third method requires an initial silanization using 3-aminopropyltriethoxysilane (APTES) followed by carrier activation with glutaraldehyde. the activated carrier in all three methods is then reacted with the amino groups of the protein. the first two non-silanizing coupling methods are simple, inexpensive and non-hazardous compared to the third, more complex method in which an initial Correspondance: to PVS     

硅基芯片表面化学性质对蛋白质固定化的影响

制备蛋白质芯片的关键在于将蛋白质固定到芯片表面并保持其生物学活性.本实验中,我们分别采用物理吸附、直接化学固定、加入间隔臂化学固定和生物亲和作用固定的方法将癌胚抗原(CEA)抗体固定到硅基芯片的二氧化硅表面.基于抗原-抗体的特异性相互作用,利用双抗体夹心酶联免疫法(ELISA)评价各种方法固定抗体的效果.实验结果表明,在修饰有氨基的表面采用戊二醛作为偶联试剂固定CEA抗体具有最高的偶联效率,引入多聚赖氨酸(poly-L-lysine)作为间隔臂可以显著增强固定效果,并可进一步降低非特异性吸附.而利用生物亲和作用固定CEA抗体也可获得较好的固定效果,但是非特异性吸附较严重.     

纳米金-蛋白A介导抗体定向固定的压电传感及电化学特性研究

以纳米金为载体标记蛋白A(PA),用于介导抗体在压电石英晶体金电极表面的定向固定化.以补体C_1q抗体为模型,采用压电传感技术实时监察了此敏感界面的免疫反应过程,并考察了与补体C_1q免疫反应的压电响应性能.金标PA固定抗体的方法与传统的直接PA固定化方法相比较,具有传感界面无需活化,固定抗体的免疫活性高等优点,可对相应抗原进行高灵敏的压电免疫检测.分别利用循环伏安和电化学交流阻抗技术对金标PA固定抗体及其免疫反应的动力学过程进行了表征.     

Surface Activation of Poly(Methyl methacrylate) by Plasma Treatment: Stable Antibody Immobilization for Microfluidic Enzyme-Linked Immunosorbent Assay

With the aim of obtaining stable antibody immobilization on the poly(methyl methacrylate), PMMA channel surface, PMMA substrates were activated with O₂ plasma treatment to introduce surface polar groups on it. The plasma-treated PMMA surfaces were characterized using water contact angle measurement, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). It was observed that plasma treatment significantly improved the surface wettability with changing surface chemistry and topography. The strategy of immobilization of a model antibody, anti-goat IgG on plasma-treated PMMA involved two steps. First the plasma-treated PMMA was functionalized with (3-aminopropyl)thriethoxy silane, APTES off-chip which facilitated covalent capturing of antibody via a crosslinking agent in the inner surface of PMMA channel in the second step. The antibody immobilization on plasma-treated PMMA was also confirmed using AFM, XPS, and fluorescence microscopy. The anti-IgG covalently captured on channel surface was evaluated with sandwich ELISA protocol on-chip using fluorescence microscopy. The observed results demonstrate that this technique could be extended to integrate the current diagnostic techniques into the plastic chip for important biomarker diagnosis.     

Surface‐Independent and Oriented Immobilization of Antibody via One‐Step Polydopamine/Protein G Coating: Application to Influenza Virus Immunoassay

For the construction of high‐performance biosensor, it is important to interface bioreceptors with the sensor surface densely and in the optimal orientation. Herein, a simple surface modification method that can optimally immobilize antibodies onto various kinds of surfaces is reported. For the surface modification, a mixture of polydopamine (PDA) and protein G was employed. PDA is a representative mussel‐inspired polymer, and protein G is an immunoglobulin‐binding protein that enables an antibody to have an optimal orientation. The surface characteristics of PDA/Protein G mixture‐coated substrates are analyzed and the PDA/protein G ratio is optimized to maximize the antibody binding efficiency. Moreover, the antibody‐immobilized substrates are applied to the detection of influenza viruses with the naked eye, providing a detection limit of 2.9 × 10³ pfu mL^‐1. Importantly, the several substrates (glass, SiO₂, Si, Al₂O₃, polyethylene terephthalate, polyethylene, polypropylene, and paper) can be modified by simple incubation with the mixture of PDA/protein G, and then the anti‐influenza A H1N1 antibodies can be immobilized on the substrates successfully. Regardless of the substrate, the influenza viruses are detectable after the sandwich immunoreaction and silver enhancement procedure. It is anticipated that the developed PDA/protein G coating method will extend the range of applicable materials for biosensing.     

Immobilization of proteins on gold coated porous membranes via an activated self-assembled monolayer of thioctic acid

A new methodology for efficient protein (e.g., antibodies, enzymes, etc.) immobilization on microporous nylon membranes for use in a variety of bioanalytical systems is introduced. The method utilizes an activated self-assembled monolayer (SAM) of thioctic acid on gold coated forms of the membranes. Via a carbodiimide mediated reaction, the protein is anchored to the gold surface through an amide bond with the terminal carboxyl group of the adsorbed thioctic acid. The immobilization efficiency is high (95% for a monoclonal immunoglobulin G(IgG) and the surface bound protein appears to be stable enough to resist any displacement by other proteins in a matrix as complex as serum. Immunological activity of immobilized antibody is retained as demonstrated via use of such membrances in colorimetric ELISA for human chorionic gonadatropin (hCG). The high protein immobilization efficiency, the high tensile strength of microporous nylon membranes, and the excellent electrochemical characteristics of gold make this approach very attractive for preparing biomembranes that should be useful in affinity chromatography, electrochemical immunosensing systems, flow-through enzyme reactors, etc.     

Advanced Immobilization and Amplification for High Performance Protein Chips

With the success of high-throughput DNA microarrays, protein biochips have been intensively investigated and broadly used in bioscience research, clinic diagnosis, drug discovery, and other applications. However, there is great need to significantly improve the sensitivity of protein chips, especially in early diagnosis. A major challenge of improving sensitivity is that protein detection does not have an effective amplification method, such as PCR for DNA microarrays. Construction of unique biofilms for efficient immobilization of protein probes and innovation of new amplification schemes could play a critical role in performance improvement of protein biochips. With dramatic developments in microfabrication, nanotechnologies, and biotechnologies, enormous progress has been made, particularly in improving biosensing sensitivity. This article reviews new advances in protein biochip technologies with emphasis on novel approaches for efficient probe immobilization and nanomaterials-assisted signal amplification for high performance protein chips. Prominent progress in integration of protein microarrays with microfluidic platforms is briefly discussed. The major challenges and perspectives on the future of protein biochips are also addressed.     

在线超滤-离子色谱法同时测定面粉中3种阴离子

采用在线超滤-离子色谱法同时测定面粉中BrO3-、NO2-、NO3-3种阴离子的含量。10.00g样品用水超声提取30min,定容为100mL,离心分离,取上清液通过0.22μm在线超滤系统进行预处理。分取20μL进样,经Metrosep A Supp 7-250阴离子分析柱和Metrosep A Supp 4/5Guard保护柱分离,以3.6mmol·L-1碳酸钠溶液为流动相进行淋洗,采用抑制电导检测器进行检测。BrO3-、NO2-和NO3-分别在0.20~10.0 mg·L-1,0.02~2.00 mg·L-1和0.25~30.0mg·L-1范围内呈线性关系,检出限(3S/N)在0.20~2.50mg·kg-1之间。应用此方法分析了3个面粉样品,并以此为基体,用标准加入法进行回收试验,测得回收率在89.0%~110%之间,测定值的相对标准偏差(n=6)在2.2%~4.6%之间。     

Conjugation of Methacrylamide Groups to a Model Protein via a Reducible Linker for Immobilization and Subsequent Triggered Release from Hydrogels

An efficient strategy is reported to introduce methacrylamide groups on the lysine residues of a model protein (lysozyme) for immobilization and triggered release from a hydrogel network. A novel spacer unit was designed, containing a disulfide bond, such that the release of the protein can be triggered by reduction. The modified proteins were characterized by MALDI‐TOF MS, titration of free NH₂ residues and spectral analysis. The modification reaction is well controlled, and the number of introduced functions can be tailored by changing the reaction conditions. Gel electrophoresis experiments showed that the methacrylamide modified protein can be immobilized in a polyacrylamide hydrogel and subsequently released by reduction of the spacer by which the protein was grafted to the polymeric network.