共查询到18条相似文献,搜索用时 78 毫秒
1.
基于银纳米粒子的传感器的应用引起了广泛关注,原因是其具有简便、高效和经济的特点。我们在水相中合成了壳聚糖修饰的银纳米粒子,通过紫外检测,实现了对色氨酸的选择识别,并初步探讨了它们作用的可能机制。 相似文献
2.
3.
以卤化银或氧化银作为前驱体,室温下以水为溶剂,在较高溶液浓度下,利用化学还原法制备了单分散性银纳米粒子,并通过改变前驱体的种类,实现了粒径可控制备。采取扫描电子显微镜(SEM)、紫外-可见光谱仪(UV-Vis)、X射线-粉末衍射仪(XRD)、X射线-光电子能谱仪(XPS)等对所制备的银纳米粒子的形貌及成分进行了表征。结果显示,所制备的银纳米粒子具有较高的单分散性,粒径在40~150nm之间,具有面心立方多晶结构。该方法制备的银纳米粒子可用于喷墨打印RFID天线。 相似文献
4.
5.
银纳米粒子在木瓜蛋白酶固定化中的应用 总被引:1,自引:0,他引:1
通过超声条件下正硅酸四乙酯与g-氨丙基三乙氧基硅烷的同步水解,一步制备了带氨基的二氧化硅微球,并在其表面沉积了银纳米粒子. 以此负载银的二氧化硅微球作为载体固定木瓜蛋白酶,研究了银纳米粒子负载量对木瓜酶固定化的影响,考察了固定化木瓜蛋白酶的性能. 结果表明,当载体的银负载量为0.68%时,固定木瓜蛋白酶活回收率达到最高,比使用未负载银的载体提高了188%;该固定酶比游离酶具有更好的热稳定性,在重复使用20次后仍保持原有酶活的43%,4℃下储存2个月后酶活基本没有下降. 相似文献
6.
7.
本文以N-(3-氨基丙基)咪唑功能化的纳米金粒子(imid-Au NPs)为探针对铀酰离子进行比色检测。imid-Au NPs的咪唑基团可与铀酰根离子形成金属螯合物,诱导imid-Au NPs聚集,致使溶液由酒红色转变为蓝色,该变化可直接通过肉眼识别,从而建立起一种简单快速且适用于现场实时检测UO2+2的可视化比色检测的方法。在最优的p H和显色时间等条件下,其它金属离子(Ni2+、Co2+、Mn2+等11种金属离子)对该比色系统无干扰。当铀酰离子浓度在1.5-13.36μmol/L范围内,该浓度与吸光度比值呈现良好的线性关系(Y=0.1552X+0.4526(R2=0.90)),最低检测限为5.84×10-8mol/L。 相似文献
8.
9.
10.
11.
Prof. Dr. Yoshitsugu Akiyama Kazunori Kimura Dr. Syuuhei Komatsu Dr. Tohru Takarada Prof. Dr. Mizuo Maeda Prof. Dr. Akihiko Kikuchi 《Chembiochem : a European journal of chemical biology》2023,24(1):e202200451
A colorimetric assay of DNA cleavage by bleomycin (BLM) derivatives was developed utilizing high colloidal stability on double-stranded (ds) DNA-modified gold nanoparticles (dsDNA-AuNPs) possessing a cleavage site. The assay was performed using dsDNA-AuNPs treated with inactive BLM or activated BLM (Fe(II)⋅BLM). A 10-min exposure in dsDNA-AuNPs with inactive BLM treatment resulted in a rapid color change from red to purple because of salt-induced non-crosslinking aggregation of dsDNA-AuNPs. In contrast, the addition of active Fe(II)⋅BLM retained the red color, probably because of the formation of protruding structures at the outermost phase of dsDNA-AuNPs caused by BLM-mediated DNA cleavage. Furthermore, the results of our model experiments indicate that oxidative base release and DNA-cleavage pathways could be visually distinguished with color change. The present methodology was also applicable to model screening assays using several drugs with different mechanisms related to antitumor activity. These results strongly suggest that this assay with a rapid color change could lead to simple and efficient screening of potent antitumor agents. 相似文献
12.
纳米银粒子的独特性能使其在电学、热学、光学、磁学、抗茵和催化等诸多领域具有广阔的应用前景.近几年,纳米银制备技术迅速发展,方法多种多样.生物法因其成本低、绿色环保和反应过程简单等优势吸引了众多研究者的关注.采用细茼或真菌等微生物合成纳米银材料一直是新材料领域研究的热点,对近几年国内外生物合成纳米银材料的方法及机理进行了... 相似文献
13.
The rediscovery of the medical uses of silver provides another noticeable example, this time at the interface of chemistry and medicine, of the real (and nonlinear) progress of scientific research. Several new silver-based antimicrobial products have thus been commercialized in the last two decades. Next-generation antibacterials and antivirals of broad scope, low toxicity and affordable cost, we argue in this study, will be based on microencapsulated Ag nanoparticles. 相似文献
14.
Kenneth K. Y. Wong Dr. Stephanie O. F. Cheung Liuming Huang Dr. Jun Niu Dr. Chang Tao Dr. Chi‐Ming Ho Dr. Chi‐Ming Che Prof. Paul K. H. Tam Prof. 《ChemMedChem》2009,4(7):1129-1135
The production of pure silver in nanoparticle size has opened new dimensions in the clinical use of this precious metal. We and others have demonstrated previously that silver nanoparticles (nAg) possess efficient antimicrobial activity. Herein we show they may also have significant anti‐inflammatory effects in a postoperative peritoneal adhesion model. This finding provides further insight into the biological actions of nAg as well as a potentially novel therapy for peritoneal adhesions in clinical surgery.
15.
Seven biological methods were adopted (three bacterial activities of bioluminescence, enzyme, enzyme biosynthetic, algal growth, seed germination, and root and shoot growth) to compare the toxic effects of two different sizes of silver nanoparticles (AgNPs). AgNPs showed a different sensitivity in each bioassay. Overall, the order of inhibitory effects was roughly observed as follows; bacterial bioluminescence activity ≈ root growth > biosynthetic activity of enzymes ≈ algal growth > seed germination ≈ enzymatic activity > shoot growth. For all bacterial activities (bioluminescence, enzyme, and enzyme biosynthesis), the small AgNPs showed statistically significantly higher toxicity than the large ones (p < 0.0036), while no significant differences were observed among other biological activities. The overall effects on the biological activities (except shoot growth) of the small AgNPs were shown to have about 4.3 times lower EC50 (high toxicity) value than the large AgNPs. These results also indicated that the bacterial bioluminescence activity appeared to be an appropriate method among the tested ones in terms of both sensitivity and the discernment of particle sizes of AgNPs. 相似文献
16.
ABSTRACT: Polyhexamethylene biguanide (PHMB), a broad spectrum disinfectant against many pathogens, was used as a stabilizing ligand for the synthesis of fairly uniform silver nanoparticles. The particles formed were characterized using UV-visible spectroscopy, FTIR, dynamic light scattering (DLS), electrophoretic mobility and TEM to measure their morphology and surface chemistry. PHMB-functionalized silver nanoparticles were then evaluated for their antimicrobial activity against a gram negative bacterial strain, E. coli. These silver nanoparticles were found to have about 100 times higher bacteriostatic and bactericidal activities, compared to the previous reports, due to the combined antibacterial effect of silver nanoparticles and PHMB. In addition to other applications, PHMB-functionalized silver nanoparticles would be extremely useful in textile industry due to the strong interaction of PHMB with cellulose fabrics. 相似文献
17.
在弱酸性缓冲溶液中,质子化的多巴胺与表面包裹着柠檬酸根负离子的纳米银相结合,引起纳米银的聚集,导致体系在442 nm处共振散射强度增强,其强度增加值与多巴胺浓度呈线性关系,据此提出了一种利用纳米银的聚集效应采用共振散射技术测定痕量多巴胺的新方法。在选定最佳实验条件下,多巴胺的线性范围为1.0×10~(-7)~2.5×10~(-5)mol/L,线性回归方程为ΔI=2.808×10~7c+8.15,相关系数为0.999 2,检出限为2.78×10~(-8)mol/L。该方法操作简便,应用于注射液、人血清和尿液中多巴胺含量的检测,其加标回收率为96.4%~103.9%,相对标准偏差为0.31%~1.28%。 相似文献
18.
Thou-Jen Whang Hsien-Yu Huang Mu-Tao Hsieh Jyun-Jen Chen 《International journal of molecular sciences》2009,10(11):4707-4718
Silver nanoparticles doped on titanium oxide (TiO2) were produced by laser-liquid interaction of silver nitrate (AgNO3) in isopropanol. Characteristics of Ag/TiO2 (Ag doped TiO2) nanoparticles produced by the methods presented in this article were investigated by XRD, TEM, SEM, EDX, and UV-Vis. From the UV-Vis measurements, the absorption of visible light of the Ag/TiO2 photocatalysts was improved (additional absorption at longer wavelength in visible light region) obviously. The photocatalytic efficiency of Ag/TiO2 was tested by the degradation of methylene blue (MB) in aqueous solution. A maximum of 82.3% MB degradation is achieved by 2.0 wt% Ag/TiO2 photocatalyst under 2 h illumination with a halogen lamp. 相似文献