硫硒化镉纳米颗粒对胰高血糖素聚集的影响

利用原子力显微镜、傅里叶变换红外光谱仪和荧光光度计等研究了硫硒化镉纳米颗粒对胰高血糖素聚集的影响, 包括聚集形成纤维数量的多少、纤维的生长速度等. 结果表明: 硫硒化镉纳米颗粒能够抑制胰高血糖素多肽的聚集, 并且随着颗粒浓度的增加, 其抑制胰高血糖素维化的程度也明显加剧. 另外, 还对纳米颗粒抑制胰高血糖素聚集的机理进行了初步讨论.     

ITO上电沉积Pd的成核机理及电催化性质

采用循环伏安技术和计时电流技术, 研究了ITO上电沉积Pd的过程, 发现Pd在ITO表面的电沉积是过电位成核且为不可逆的扩散控制过程; 根据Cottrell方程计算得到[PdCl₄]^2-的扩散系数为2.19×10^-5 cm²/s; 根据Scharifker的理论模型, 归一化处理电流-时间曲线, 与理论成核曲线对照, 判断Pd 的成核机理. 通过场发射扫描电子显微镜(FESEM)对Pd 的形貌进行分析, 讨论了沉积电位和沉积时间对Pd纳米粒子形貌的影响. 用X射线粉末衍射(XRD)对Pd纳米粒子进行结构分析, 并在0.5 mol/L H₂SO₄溶液中研究了其电化学性质及在碱性条件下乙醇分子的电催化性质.     

Metallic iron nanoparticles: Flame synthesis,characterization and magnetic properties

Metallic iron (Fe) nanoparticles (NPs) with a typical core–shell structure have been prepared by a simple and continuous flame spray pyrolysis (FSP) method, which are stabilized by the corresponding Fe₃O₄ shell with a thickness of 4–6 nm. The size of metallic Fe cores is about 30–80 nm. The core–shell structured iron NPs show an air stability as long as one month as a result of the protection of oxide shell. Through the control of the residence time of materials in flame and flame atmosphere, metallic Fe and iron oxides are obtained, showing a better external magnetic field responsibility. It is concluded that the evolution of morphology and composition of flame-made magnetic NPs could be attributed to the competition mechanism between reduction and oxidation reactions of in situ flame combustion, which offers more choices and better effective design strategy for the synthesis of advanced functional materials via FSP techniques.     

Z型可见光催化剂Au NPs/g-C3N4/BiOBr的构建及其光催化性能

通过水热和原位还原法制备了一种新型Z型异质结三元复合材料Au NPs/g-C₃N₄/BiOBr,并通过X射线衍射、X射线光电子能谱、透射电子显微镜、紫外-可见漫反射光谱和光致发光发射光谱等技术对材料的形貌、结构进行了表征。通过在可见光下降解苯酚来评价光催化剂的活性。研究发现,Au NPs/g-C₃N₄/BiOBr显示出增强的光催化活性,对苯酚的降解能力是g-C₃N₄的3倍,是BiOBr的2.5倍。这可归因于三元复合材料的窄带隙（2.10eV）、Z型机理对光生电子-空穴对的有效分离和Au纳米颗粒的表面等离子体共振效应（SPR）。     

基于铂氧化铜负载多壁碳纳米管标记夹心型电化学免疫传感器

设计了一种夹心型电化学免疫传感器,以金负载二氧化锡石墨烯（GS－SnO2－Au）为检测平台,铂氧化铜负载多壁碳纳米管（Pt@CuO－MWCNTs）为标记物,用于乙肝表面抗原（HBs）的定量检测。GS－SnO2－Au具有较高比表面积,良好的导电性、分散性和生物相容性,有利于捕获大量抗体（Ab1）。Pt、CuO和多壁碳纳米管对H2O2分解均具有催化性,Pt@CuO－MWCNTs复合物能协同放大催化作用,实现多重放大信号的效果,有利于实现高灵敏检测。通过透射电镜表征GS－SnO2－Au和Pt@CuO－MWCNTs的形貌特征。结果表明,基底材料和标记物材料的性能良好。在最佳实验条件下：磷酸盐pH值7.4,GS－SnO2－Au的质量浓度为1 mg/mL,Pt@CuO－MWCNTs质量浓度为2 mg/mL,该免疫传感器对HBs的线性范围为0.001 ~ 100 ng/mL,检出限为0.33 pg/mL,对实际样品的加标回收率为99.8% ~ 100%,相对标准偏差（RSD）为1.1% ~ 1.5%。所设计的免疫传感器具有良好选择性、重现性和稳定性,在HBs的临床检测方面具有潜在应用价值。     

Cytotoxic performance of green synthesized Ag and Mg dual doped ZnO NPs using Salvadora persica extract against MDA-MB-231 and MCF-10 cells

In this study, dual doped Zinc oxide nanoparticles consisted of silver and magnesium were prepared by Salvadora persica extract. Powder X-ray diffraction (PXRD) analysis displayed the formation of wurtzite ZnO phase nanostructures and dual doped nanoparticles. The morphological observations of scanning electron microscopy (SEM) confirmed the hexagonal morphology of prepared nanoparticles. The Raman scattering of this product exhibited the first and second orders of polar and non-polar modes that are the characteristic bonds of a wurtzite structure. The toxicity effects of synthesized un-doped, as well as Ag and Mg dual doped ZnO NPs on breast cancer cell (MDA-MB-231) and breast normal cell (MCF-10A) lines, were investigated by the means of MTT test. Accordingly, in comparison to the case of silver and magnesium doped zinc oxide nanoparticles, the un-doped ZnO NPs caused a more toxic impact on MDA-MB-231cells. There was a lack of any significant toxicity effects from un-doped and Ag and Mg dual doped ZnO nanoparticles on the experimented normal cell line (MCF-10A). The gathered results were indicative of a lower toxicity effect in doped nanoparticles when compared to un-doped nanoparticles and therefore, it can be stated that the doping of silver and magnesium metals produces more reliable zinc oxide nanoparticles.     

Synthesis of chitosan-stabilized copper nanoparticles (CS-Cu NPs): Its catalytic activity for C-N and C-O cross-coupling reactions and treatment of bladder cancer

Herein, we report the synthesis of copper nanoparticles at ambient conditions using biopolymer, chitosan, as a protecting and stabilizing agent and hydrazine as a reducing agent. The obtained nanoparticles (CS-Cu NPs) were characterized using XRD, FT-IR, FE-SEM, EDS, TEM and UV–Vis spectroscopy. This nanocomposite was utilized as an efficient heterogeneous nanocatalyst for the aryl and heteroaryl C–N and C–O cross coupling reactions with excellent yields at mild conditions. The nanocatalyst were isolated and reused for 10 times with reproducible catalytic activity. Cell viability of nanocomposite was very low against bladder cancer (UM-UC-3 (Transitional cell carcinoma), SCaBER (Squamous cell carcinoma), and TCCSUP (Grade IV, transitional cell carcinoma)) cell lines without any cytotoxicity on the normal cell line. The best anti-human bladder cancer properties of nanocomposite against the above cell lines was in the case of TCCSUP cell line. According to the above findings, the nanocomposite may be administrated for the treatment of several types of human bladder cancer in humans.     

The Effect of Nano-ZnO on Seeds Germination Parameters of Different Tomatoes (Solanum lycopersicum L.) Cultivars

The agriculture sector faces numerous problems. One of the beforementioned problems relates to the proper crop plants’ fertilization. The conventional bulk fertilizers are becoming less effective and have a negative impact on the environment. Nanomaterials such as zinc oxide nanoparticles (ZnO NPs) are widely used in various sectors such as medicine or electronics. Several studies indicate that nano-ZnO may likewise be considered as a potential nanofertilizer. In present research, an attempt was made to study the influence of two different sized ZnO NPs (<50 nm and <100 nm) on the seed germination of chosen tomato (Solanum lycopersicum) cultivars. The seeds of three cherry tomato cultivars were placed on a Petri dish with the NPs suspensions (0, 50, 150, and 250 mg/L) in order to examine the influence on germination parameters at a certain size of NPs and at a chosen concentration. In addition, within this study, we verified that the implicated conditions have the exact impact on all three cultivars. The obtained results indicate that all the factors affect the seed sprouting, however, this process mainly depends on the type of tomato cultivar and the size of the used nanoparticles. The parameter of the germination percentage (GP) was the only of the assumed factors that did not influence it significantly. Nevertheless, the values of other examined parameters such as the MGT, GRI, CVG, or VI depend strongly on all assumed features including the type of chosen cultivar. The obtained results vary significantly between all cultivars which indicates that the plants from the same family may require different conditions for optimal growth. In this research the <50 nm ZnO nanoparticles had more beneficial influence on sprouting parameters then parallelly used <100 nm ZnO nanoparticles.     

亲水性FePt纳米颗粒协同催化有机污染物的降解

以半胱氨酸为配体,采用一锅法简便合成了亲水性的FePt纳米颗粒(NPs).超小的FePtNPs对水中常见有机污染物表现出良好的催化降解性能,以NaBH₄为还原剂时可实现对染料罗丹明B(RhB)和有害物质4-硝基苯酚(4-NP)的有效还原;以H₂O₂为氧化剂时可实现亚甲基蓝(MB)的高效降解.实验结果表明,FePtNPs对3种有机污染物的降解率均高于90%.对Fe Pt原子对之间的协同催化机理进行了探讨,揭示了不同反应体系中微观反应历程和催化机理的区别.磁性测试结果表明,FePt催化剂可以通过外加磁场进行收集并重复利用,解决了催化剂二次污染问题.该研究为设计合成绿色环保催化剂提供了思路.     

Green chemical synthesis of Pd nanoparticles for use as efficient catalyst in Suzuki‐Miyaura cross‐coupling reaction

Herein, we report the synthesis of tiny spherical Pd nanoparticles (NPs) by green chemical method under ambient conditions using flower extract of Lantana camara plant. The size of the Pd NPs is tunable from 4.7 to 6.3 nm by systematically controlling the concentration of either metal ions or plant extract. The synthesized Pd NPs were well characterized by different spectroscopic, microscopic and diffractometric techniques. The Pd NPs offered good size‐dependent catalytic activity in the Suzuki‐Miyaura C‐C coupling reaction under mild reaction conditions in (1: 1) water‐ethanol mixture. The catalyst is stable and exhibited excellent reusability up to three cycles of coupling reaction after which the catalytic activity decreases.