磁性纳米材料在兽药残留检测应用中的研究进展

磁性纳米材料是一种具有稳定磁学性能、极小生物背景干扰以及丰富化学性能的新型功能复合型材料,与免疫技术、分子印迹技术及传感器技术等结合,开始应用于兽药残留检测中的样品前处理与检测过程,以此提高检测的灵敏度。本文主要对其中的磁固相萃取、磁性分子印迹技术、磁免疫层析技术以及磁生物传感器技术进行介绍,综述了其在兽药残留分析中的研究进展。     

纳米传感器在农药残留检测中的应用研究进展

农药残留是影响食品安全的主要风险因素之一。传统的农药残留检测方法由于需要昂贵、大型的检测仪器往往不能满足现场、实时检测的需要。近年来,随着纳米材料制备及功能化技术日趋完善,其在农药残留快速检测领域的研究日益活跃。纳米材料与荧光法、比色法、表面增强拉曼散射法及电化学法结合,可构建各类纳米传感器,在检测特异性和灵敏度上有较大提升,实现了快速检测技术的突破。本文综述了上述4类主要的纳米传感器在农药残留快速检测中的应用,并对其应用前景进行展望。未来构建选择性高、分析范围广、抗干扰、简单便携的纳米传感器仍将是农药残留检测领域主要的研究方向。     

基于SERS技术的基底增强效应对比及食源性芽孢快速检测

为了实现食源性芽孢的快速识别,该研究利用表面增强拉曼光谱技术,以产气荚膜梭菌芽孢(C.perfringens spores)、艰难梭菌芽孢(C.difficile spores)和生孢梭菌芽孢(C.sporogenes spores)为研究对象,将3种不同纳米溶胶材料Au NPs、Ag NPs和Au@AgNPs作为表面增强拉曼散射(Surface-enhanced Raman scattering,SERS)基底对食源性芽孢的增强效应进行对比,确定较佳增强效果的纳米材料,进一步开展基于较优纳米溶胶材料为基底的SERS技术对不同种属食源性芽孢的光谱解析及快速识别研究。结果表明,Au@Ag NPs对食源性芽孢的SERS增强效果最较好,其增强因子达3.49×10⁴,且光谱特异性和重现性良好。经拉曼光谱解析,Ca²⁺-DPA的拉曼峰是三种食源性芽孢的共有标志特征峰,拉曼振动峰在1 017、1 440和1 570 cm^-1波段显示且峰强度不同。C.perfringens芽孢在740、787、821、1 203、1 308和1 62...     

Promoting effect of Nano-Se on tobacco growth and reactive oxygen species metabolism

Abstract

Se is beneficial to plants’ growth and it is an essential mineral for animals and humans. However, relatively little is known about the relationship between nano-Se concentrations and plant antioxidant activity. In this work, a pot experiment was carried out using two cultivars of tobacco and increasing nano-Se concentrations. The changes of plant biomass, root growth, chlorophyll content, nutrient accumulation and reactive oxygen species (ROS) content in tobacco leaves after being sprayed with nano-Se were studied. The results indicated that the growth of tobacco can be promoted by applying nano-Se in an appropriate concentration. In addition, our research proves that there is cultivars variation in the response of tobacco to increased concentrations of nano-Se. The biomass, root growth characteristics, chlorophyll content and N accumulation of E'yan 1 were increased significantly and were the highest at 5.0?mg L^?1 of nano-Se. On the other hand, the above mentioned indicators for K326 reached the maximum value at 2.5?mg L^?1 and decreased at 5.0?mg L^?1 of nano-Se. The antioxidant enzymes activity were increased by the application of nano-Se, however cultivars variation was detected. The application of nano-Se reduced the amount of thiobarbituric acid reactive substances (TBARS) and ROS at 5.0?mg L^?1 for both cultivars. This study confirms that nano-Se affects positively the growth and oxidative status of tobacco plants. However, this study points out that more research is needed to understand the interaction phenomena observed here between tobacco cultivars and concentrations specifically for the anti-oxidant status of the plant.     

Cu元素纳米材料的研究进展

介绍了Ｃｕ元素纳米材料的结构特征和独特性能,及其制备、表征方法和应用等方面的研究进展。     

纳米材料对辣椒种子萌发的作用参数优化

为了优化纳米材料对辣椒种子萌发的作用参数,试验分两个阶段进行,第一阶段用纳米材料不同时间处理的活化水浸种,筛选出适宜辣椒种子萌发的纳米材料活化水时间范围第二阶段。参考第一阶段试验结果,进行活化时间和浸种时间交互试验,研究最适宜辣椒萌发的活化时间和浸种时间组合。结果表明:纳米材料活化水1.0h处理在促进辣椒种子萌发方面效果最好,最适宜辣椒萌发的活化时间和浸种时间组合以A2B5(活化时间70min、浸种9h)综合表现最佳。     

纳米材料在免疫传感器中的应用

纳米技术是21世纪的一次技术革命,纳米材料作为纳米技术的重要组成部分,已渗入到多学科当中,并在医学领域中得到广泛的应用。由于纳米材料所特有的特性即小尺寸效应、表面效应、量子尺寸效应和宏观量子隧道效应,使纳米材料在电化学、压电和光学免疫传感器中广泛应用,提高了传感器的选择性、准确性、重复性、灵敏度和响应速度,同时使其向着微型化、集成化方向发展。     

Impact of carbon nanomaterials on microbial activity in soil

In this study, effects of an increase in concentration of fullerene-C_60, single-walled carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWCNTs) or fullerene soot (FS) on overall microbial activity was investigated over a 21 d incubation period. Microbial utilisation of ¹⁴C-glucose and uptake of ¹⁴C-glucose into the microbial biomass was investigated. For CNM-amended soils, greater extents of ¹⁴C-glucose mineralisation were found in the C₆₀-amended soils compared to MWCNT-, SWCNT- or FS-amended soils. In addition, the 100 and 1000 mg kg⁻¹ were consistently found to have higher extents of mineralisation in C₆₀, MWCNT, SWCNT or FS-amended soils, respectively. Further, the incorporation of ¹⁴C-glucose into the microbial biomass declined slightly with an increase in concentration in the amended soils, but no consistent pattern was observed. As a result, the biophysical quotient (BQ) increased significantly (P < 0.05), as concentrations increased from 1 mg kg⁻¹ to 1000 mg kg⁻¹ in all C₆₀-, MWCNT-, SWCNT- and FS-amended soils. The results obtained from this study showed that the addition to carbon nanomaterials had no profound impacts on the overall microbial activity, and the overall influence of CNMs on soil microbial activity does not reveal a specific pattern in the short term.     

Kinetics Stability of Nanoparticles Colloids

The dimension of nano-particles is close to the dimension of colloid particles. The dispersion system of nano-particles is colloid. The sedimentation rate of nano-particles dispersed in water is calculated, and it is shown that the sedimentation rate is very slow and the nano colloids have high stability on dynamics. Those conclusions are approved by tests. The influence of electric characters of the colloid and macromolecule was introduced. The results of the study maybe out of the image of most people and are useful to change their attitude of the kinetics stability of real nano particles colloid.     

纳米材料在兽药残留分析中的应用

食品安全问题是当今全球关注的热点,特别是动物性食品中抗生素和违禁药物残留问题,已引起世界各国的高度重视,灵敏、安全、经济的检测手段是当前制约动物性食品中兽药残留检测的瓶颈,采用现代科技最新研究成果之一的纳米材料提高检测方法的灵敏度将是一条大有希望的途径。纳米材料特别是半导体纳米晶体,由于量子尺寸效应,具有激发光谱宽、发射光谱窄、荧光强度高、稳定性好等特点,其生物兼容性和超顺磁性在兽药残留分析中具有很大潜力。现就纳米材料的最新研究进展特别是纳米材料在兽药残留分析中免疫检测、免疫组化及基质净化等方面的应用潜力做一简要综述。