荧光纳米材料应用于蛋白质分析的研究进展

蛋白质与人体新陈代谢、免疫应答和疾病发生等密切相关,因此对蛋白质研究是当今世界共同关注的热点,目前已经渗透到生物、医学、食品等各个领域。纳米技术的发展极大地促进了蛋白质技术的研究,发展光学特性优良、生物相容性好的功能化荧光纳米材料对深入研究蛋白质的标记、分析以及分离具有非常重要的意义。本文主要介绍了半导体量子点、嵌入式核壳荧光纳米颗粒、碳点、碳纳米管、贵金属元素纳米簇和磁性荧光纳米颗粒等荧光纳米材料的基本性质,以及各种荧光纳米材料在蛋白质标记成像、蛋白质相互作用、蛋白质固定与分离以及蛋白质分析检测方面的应用。     

纳米二氧化钛的制备及其在自清洁材料的应用

作为一种新型的无机纳米材料,纳米二氧化钛（TiO2）颗粒不仅具有优异的光催化性质和防紫外性能,还具有很高的化学稳定性、热稳定性、超亲水性、非迁移性和无毒性等特征。详细阐述了纳米TiO2颗粒的晶型结构特征、催化机理和制备方法,简单介绍了其在自清洁材料方面的应用。列出了目前制约纳米TiO2颗粒发展的一些问题．对其进一步的研究和应用进行了展望。     

纳米技术与防护服

<正>纳米材料具有与传统晶体和非晶体材料完全不同的独特性质,因此,纳米技术在电子学、光学、化工、陶瓷加工、生物工程和医药学等领域得到应用,并相继取得重大进展。纳米技术在防护领域的应用尚属科学实验阶段,但随着纳米电子学、纳米材料学、纳米化学、纳米生物学、纳米机械     

纳米金在食品安全检测中的应用研究进展

纳米金具有良好的生物相容性和独特的光学性质,可与生物和有机分子结合,形成功能化的纳米金。基于这些特性,纳米金在食品安全检测方面有着广泛的应用。本文综述了纳米金在食源性致病菌、生物毒素、重金属离子、药物残留、食品添加剂及非法添加物和其他食品有害因子检测中的应用实例,并对纳米金在食品安全检测方面的应用进行了展望。     

激光烧蚀银等离子体特性分析

金属纳米材料因具有的独特的表面效应、小尺寸效应和量子效应,使得金属纳米材料在光学、电学、磁学、生物医学、传感等多个方面得到了广泛的开发和利用。其中Au、Ag金属纳米材料因为其具有优良的物理化学特性,逐渐成为基础研究领域的热门方向。文章首先介绍了激光烧蚀法制备银纳米粒的制备方法,通过对银纳米粒子的特性进行分析,描述了其在光学、抗菌、催化等方面的优异特性。最后浅谈了金属纳米材料在催化,磁性,生物学方面的应用及发展前景。     

木质素中空纳米球的制备和应用研究进展

木质素中空纳米球是一种具有球形和独特中空结构的纳米颗粒,具有高的比表面积、生物相容性和高负载能力等特点,在生物医学、紫外防护、新能源等领域具有广阔的应用前景。本文针对自组装制备木质素中空纳米球的过程进行剖析,总结了近年来国内外溶剂-反溶剂法、界面细乳聚合法、模板法和交联/偶联聚合法等自组装方法制备纳米颗粒的形成过程与机理,以期对开发简单可控的自组装方法制备木质素中空纳米球、高效资源化应用提供借鉴。     

纳米纤维支架在神经组织工程中的应用进展

采用纳米技术生产的组织工程材料具有独特的生物学性能,在神经组织工程中的应用研究成为人们关注的热点。静电纺丝、自组装等纳米纤维支架在神经组织工程中的应用已有大量报道,研究结果表明纳米材料在神经组织工程领域有着良好的应用前景。对纳米纤维支架在神经组织工程中的应用研究现状及发展前景进行了综述。     

纳米级改性淀粉及食品应用研究进展

纳米级改性淀粉是特征尺度至少在一个维度上为纳米量级的改性淀粉,根据形态可分为淀粉纳米颗粒和淀粉纳米纤维两类。近年来,纳米级改性淀粉因其独特的纳米材料特性,以及原料来源广、可生物降解、生物相容性好等优点,在包装新材料、活性成分包埋、食品质地改良等方面具有重要的潜在应用价值,逐渐成为食品纳米科技研究的热点。文中在介绍淀粉纳米材料形态的基础上,进一步对纳米级改性淀粉的"自上而下"及"自下而上"2种制备方法及其性能改良方法进行阐述,并总结了纳米级改性淀粉的基本理化性质及在食品领域的研究应用。     

结构DNA纳米新技术的研究现状与应用

综述了结构DNA纳米技术——DNA自组装、DNA折纸术和SST自组装的研究现状,并以郑州轻工业学院校徽设计中引入DNA折纸术构建校徽DNA结构模型、利用SST自组装方法设计构造镂空结构的校徽图形为例,对结构DNA纳米技术予以评析与探讨;鉴于该技术目前主要应用于引导无机纳米粒子精确装配、装备纳米生物芯片以及与微加工技术相结合等方面,提出:纳米电子电路及器件、纳米光电子学、高灵敏度高特异性生物传感器、分子机器人、材料学和纳米医学等领域,将是结构DNA纳米技术应用未来的发展方向.     

蚕丝作为生物模板合成无机纳米材料的进展

蚕丝作为一种重要的天然高分子材料,在生物、医学等领域有着重要的应用。随着对蚕丝研究的深入,人们发现丝蛋白具有精密、特殊的结构和规则的尺寸,利用丝蛋白的活性位点和自组装性能,可作为生物模板合成无机纳米材料。重点介绍了蚕丝作为生物模板合成无机纳米材料的进展。最后指出了蚕丝作为生物模板合成无机纳米材料存在的问题。     

纳米金比色法在食品安全检测中的应用研究进展

纳米金粒子具有独特的物理、化学特性及较好的生物相容性,是目前现有的纳米材料中应用和研究最多的材料之一,其在诸多领域如生物传感器、表面电化学分析、免疫分析、药物传递以及治疗等方面都具有广阔的应用前景。纳米金具有极高的消光系数和强烈的粒子间距效应,其在分散状态下呈红色,变为交联团聚状态后呈蓝色,依据该特性建立了各种各样的纳米金比色快速检测方法。由于纳米金比色法具有操作简便、成本低廉、结果肉眼可见且灵敏度较高等优点,近年来在分析化学尤其是快速检测领域发展迅速,许多影响食品安全的有害物质可通过直接或间接作用影响纳米金的聚合状态,从而使纳米金比色法在食品安全检测中的应用成为可能。本文综述了纳米金比色法的原理及其在食品安全各类污染物中的检测应用,并总结了该方法面临的问题,提出了将来的发展方向。     

Copper-based nanoparticles for biopolymer-based functional films in food packaging applications

This review summarizes the latest developments in the design, fabrication, and application of various Cu-based nanofillers to prepare biopolymer-based functional packaging films, focusing on the effects of inorganic nanoparticles on the optical, mechanical, gas barrier properties, moisture sensitivity, and functional properties of the films. In addition, the potential application of Cu-based nanoparticle-added biopolymer films for fresh food preservation and the effect of nanoparticle migration on food safety were discussed. The incorporation of Cu-based nanoparticles improved the film properties with enhanced functional performance. Cu-based nanoparticles such as copper oxide, copper sulfide, copper ions, and copper alloys affect biopolymer-based films differently. The properties of composite films containing Cu-based nanoparticles depend on the concentration of the filler, the state of dispersion, and the interaction of the nanoparticles with the biopolymer matrix in the film. The composite film filled with Cu-based nanoparticles effectively extended the shelf life by maintaining the quality of various fresh foods and securing safety. However, studies on the migration characteristics and safety of copper-based nanoparticle food packaging films are currently being conducted on plastic-based films such as polyethylene, and research on bio-based films is limited.     

Gold nanoparticles: From synthesis,properties to their potential application as colorimetric sensors in food safety screening

BackgroundFood safety management and guarantee are the basic requirement during food processing, circulation, storage, and marketing. Elevating the ability to evaluate food quality and safety in a rapid, sensitive and reliable manner is of great importance in food industry. Recently, gold nanoparticles due to unique optical property, ease of functionalization and preparation, and high selectivity and sensitivity have received considerable attention in the field of food safety.Scope and approachGold nanoparticles exhibit distinguishable optical characteristic in different aggregated states and thus have been developed into simple colorimetric sensors for the quick detection of chemical contaminants in food samples. Herein, we reviewed the current methods for synthesis and functionalization of gold nanoparticles, strategies for fabrication of gold nanoparticle based colorimetric sensors and their applications in rapid analysis of food contaminant. Moreover, the inherent optical property of gold nanoparticles and their detecting principle have been highlighted. Finally, the main challenges and future efforts in developing such colorimetric sensors for food contaminants detection were discussed.Key findings and conclusionsGold nanoparticles as smart colorimetric sensors conform to the requirement of modern analysis, such as high selectivity, sensitivity, simplicity, celerity, and portability. Thus, they have great potential to be applied as power sensing tools for food safety screening.     

Food emulsifier based on the interaction of casein and butyrylated dextrin for improving stability and emulsifying properties

Green hydrophobically modified butyrylated dextrin (BD) was used to modulate casein (CN). The CN/BD complex nanoparticles were formed at different CN-to-BD mass ratios based on a pH-driven technology. The interaction force, stability, and emulsifying properties of complex nanoparticles were investigated. The nanoparticles had a negative charge and a small particle size (160.03, 152.6, 155.9, 206.13, and 231.67 nm) as well as excellent thermal stability and environmental stability (pH 4.5, 5.5, 6.6, 7.5, 8.5, and 9.5; ionic strength, 50, 100, 200, and 500 mM). Transmission electron microscopy demonstrated the successful preparation of complex nanoparticles and their spherical shape. Fourier transform infrared spectroscopy, fluorescence spectroscopy, and dissociation analysis results showed that the main driving forces of formed CN/BD nanoparticles were hydrogen bonding and hydrophobic interaction. Furthermore, the CN/BD nanoparticles (CN/BD mass ratio, 1:1; weight/weight) exhibited the lowest creaming index, and optical microscopy showed that it has the most evenly dispersed droplets after 7 d of storage, which indicates that the CN/BD nanoparticles had excellent emulsifying properties. Butyrylated dextrin forms complex nanoparticles with CN through hydrogen bonding and hydrophobic interaction to endow CN with superior properties. The results showed that it is possible to use pH-driven technology to form protein–polysaccharide complex nanoparticles, which provides some information on the development of novel food emulsifiers based on protein–polysaccharide nanoparticles. The study provided significant information on the improvement of CN properties and the development of emulsions based on CN.     

纳米SiO2对淀粉浆膜耐磨损性能的影响

 利用纳米SiO₂粒子改善淀粉浆料,通过试验分析纳米SiO₂提高淀粉浆料浆膜耐磨损性能的原理。将处理后的纳米SiO₂粒子添加到淀粉浆料中制备成膜,并用耐磨试验机测试了纳米SiO₂粒子含量对浆膜耐磨性能的影响。同时,通过AFM、SEM、视频变焦显微镜对浆膜表观形貌结构和磨损机制进行了表征。结果表明,添加适量纳米SiO₂的混合浆料的浆膜比纯淀粉浆料的浆膜具有更好的耐磨损性,而且当纳米SiO₂含量为3%时,混合浆料浆膜的耐磨性能最好。     

拉曼增强技术对纸张添加剂高灵敏检测的研究

通过溶胶自组装法制备了表面包覆有银纳米颗粒的高灵敏度和便携式表面增强拉曼散射（SERS）检测的球形光纤探针，然后在银纳米颗粒上面再沉积一层Parylene-C纳米薄膜实现球形光纤探针的可重复利用性。实验表明，沉积Parylene-C纳米薄膜的球形光纤探针重复使用50次仍基本没有变化，且清洗3 min后残留的罗丹明6G（R6G）分子即呈稳定状态；而未沉积Parylene-C纳米薄膜的球形光纤探针经过10次冲洗后峰值已变弱，且经过15 min的清洗R6G分子才趋于稳定。最后，利用包覆有银纳米颗粒的光纤探针对4种不同厂家生产的纸张进行了检测。结果表明，自制球形光纤探针可检测出纸张中浓度较低的添加剂成分，最低浓度为10^-12 mol/L。     

Robust size control of bovine serum albumin (BSA) nanoparticles by intermittent addition of a desolvating agent and the particle formation mechanism

In polymeric nanoparticle preparation, despite similar conditions, large fluctuations in particle size distributions are usually observed. Herein, we demonstrate that the intermittent addition of a desolvating agent can improve reproducibility in the preparation of polymeric bovine serum albumin (BSA) nanoparticles. Using this modification, BSA nanoparticles of controlled size can be manufactured with narrow particle size distributions. In our study, ethanol as a desolvating agent was added intermittently to 1% BSA solutions at different pHs with stirring at 700 rpm. The effect of the preparation parameters on size and optical density of the fabricated nanoparticles were studied. The average particles sizes of BSA nanoparticles prepared at pH values of 6, 7 and 9 were approximately 100, 200 and 300 nm, respectively. As ethanol addition increased, desolvation of BSA molecules resulted in formation of loose-structured particles with pH-dependent size. Beyond that, only particle density increased, but size remained unchanged with further addition of ethanol. Consistently uniform particle size distribution was achieved by adding ethanol intermittently.     

Methods of nanoparticles control in food and biological objects. Report 1. Use of microscopic and chromatography investigation methods

One of the promising applications of modern nanotechnology are food productions, which includes the improvement of food packaging, creation of new forms of nutrients that are characterized by improved assimilation and technological characteristics, quality control through the creation of compact and cheap test kits. All these applications of nanomaterials related to the risks of the possibility of receipt of potentially toxic nanoparticles in the diet. The task of regulation and hygienic standardization requires developing of the methods, their qualitative and quantitative analysis for such complex, multicomponent systems, which are the agricultural commodities and food products. The best hope in this plan are assigned to a group of approaches related to the microscopic visualization of artificial nanoparticles in the biological objects. While the typical size of nanoparticles (<100 nm) are below the theoretical maximum-resolution light optical methods, transmission electron microscopy often allows not only to identify nanoparticles on their size and shape, but also a qualitative and quantitative analysis their chemical composition with the use of additional analytical options. Another group of elaborate methods used in solving the problems of qualitative and quantitative analysis of nanoparticles are chromatographic methods, in particular, the exclusion, hydrodynamic, high-performance liquid chromatography, and the flow-field fractionation. Limitation of chromatographic approaches related with the need of complex sample preparation, as well as specific difficulties in nanoparticles detecting in chromatographic fractions. Transmission electron microscopy and high-performance liquid chromatography methods are officially recommended in Russia for the analysis of artificial nanoparticles in natural biological systems, including food products.     

大豆分离蛋白-花青素共价复合物制备纳米颗粒及其Pickering乳液特性分析

构建大豆分离蛋白-花青素共价复合纳米颗粒,以粒径、Zeta电位、自由基清除能力、光学显微镜观察为指标,对纳米颗粒和Pickering乳液进行研究。结果表明,通过添加花青素在一定程度上改变了纳米颗粒和Pickering乳液的粒径分布与Zeta电位值;对比可知,添加花青素后纳米颗粒和乳液体系更加稳定。此外,当花青素添加量为0.15%时,纳米颗粒的粒径分布较为均一,粒径相对体积最大;纳米颗粒Zeta电位绝对值最大;自由基清除能力相对较强;并且以0.15%花青素添加量的纳米颗粒制备的Pickering乳液液滴分布较为均匀,不易发生聚集,较为稳定。     

Visual detection of melamine in raw milk using gold nanoparticles as colorimetric probe

We report the development of a simple and rapid colorimetric detection method for melamine in raw milk using gold nanoparticles as probe. This assay relies upon the distance-dependent optical properties of gold nanoparticles. In neutral media, melamine could rapidly induce the aggregation of gold nanoparticles, thereby resulting in red-to-blue (or purple) colour change. The concentration of melamine in raw milk can be determined by monitoring with the naked eye or a UV–vis spectrometer. The present limit of detection for melamine is 0.4 mg/L. The method is rather simple, and the whole process including sample pretreatment takes only 12 min at room temperature. The merits (such as simplicity, rapidity, low cost and visual colorimetry) make the proposed method specially useful for on-site screening melamine levels well below the current safety limit in raw milk.