金属离子诱导Aspergillus sp. WL-Au合成纳米金的特性

纳米金凭借其独特的光电特性、良好的稳定性及生物相容性被广泛应用于工业催化、污染控制及医学诊断等领域。近年来,微生物法合成纳米金具有绿色低毒、条件温和、成本低廉等优势而倍受关注。然而,如何对纳米金的形貌尺寸进行定向调控仍有待进一步探究。该研究选取Fe^(3+)、Zn^(2+)、Al^(3+)、Co^(2+)、Ni^(2+)、Pb^(2+)及Sn^(2+)等多种金属离子,诱导曲霉菌(Aspergillus sp.) WL-Au合成纳米金,对其形貌进行定向调控。紫外-可见光谱分析结果表明,经Fe^(3+)、Sn^(2+)诱导的菌株合成的纳米金分散性较好,其余金属离子诱导菌株合成的纳米金单分散性较差、易沉聚。透射电子显微镜分析结果表明,大多数金属离子诱导菌株合成的纳米金为球形和伪球形,有少量的三角形;其中,经Fe^(3+)诱导后,菌株WL-Au胞外合成形貌均一、粒径较小的球形纳米金,而经Pb^(2+)诱导后,合成形貌均一的纳米棒。此外,Fe^(3+)诱导菌株合成的球形纳米金对4-硝基苯酚具有良好的催化还原性能,其催化速率常数k为13.3×10^(-3)s^(-1)。研究表明曲霉菌(Aspergillus sp.)WL-Au经Fe^(3+)诱导后可显著提高胞外合成纳米金的能力,且合成的纳米金具有形貌均一、分散性好、催化速率高的特点,在催化还原污染物方面具有较好的应用潜力。

大体积样品堆积-毛细管电泳-紫外检测分析鼠肝中不同亚型金属硫蛋白

制备了均匀稳定的聚丙烯酰胺涂层毛细管,有效抑制了毛细管内壁对金属硫蛋白(MT)的吸附,大大提高了MT的分离度和分离重现性。基于此,建立了大体积样品堆积-毛细管电泳-紫外检测法(LVSS-CE-UV)分析鼠肝中MT的新方法。在最优化的条件下,该方法对两种MT亚型(MT-1/2)的富集倍数分别为13、11倍,检出限分别为0.80、1.01μg·m L^(-1)。将所建立的LVSS-CE-UV方法用于经Cd^(2+)、Zn^(2+)诱导的Sprague Dawley大鼠肝脏中MT-1/2的定量分析,结果表明经Cd^(2+)、Zn^(2+)诱导的鼠肝内均检测出MT-1/2。其中,经Zn^(2+)诱导的鼠肝内MT-1与MT-2的含量分别为31.9、24.3μg·g^(-1);Cd^(2+)诱导组的MT-1与MT-2分别为15.9、31.2μg·g^(-1)。

无定形Fe基MOF材料的制备及析氧性能研究

采用外来金属离子诱导策略,通过一步溶剂热法成功制备了一系列In x Fe y-aMOF材料,并探究其在析氧反应中的应用.XRD、TEM和N 2吸附结果表明:Fe 3+的引入使原始晶态In-MOF失去长程有序结构,无序的纳米结构拥有较高的比表面积和丰富裸露的金属活性位点,有利于电催化反应进行.Fe-aMOF表现出最佳的析氧反应活性:在电流密度为0.01 A/cm^(2)时,过电位仅为258.2 mV,塔菲尔斜率为45.4 mV/dec.此外,Fe-aMOF还具有长期稳定性,在0.01 A/cm^(2)时至少可以连续运行110 h.该研究为合理设计和构建新一代高效电催化剂提供了一种独特的思路.

Fluorescence Enhancement of Polyamine Derivatives of 1,8-Naphthalimide with Transition Metal Ions

A series of fluorescent chemosensors 1-3 were synthesized to detect transition metal ions. At the room temperature, fluorescence intensities of these chemosensors in acetonitrile without transition metal ions were found to be very weak, due to the process of the efficient intramolecular photoinduced electron transfer （PET）. However, after addition of the transition metal ions, the chemoscnsor 1-3 exhibits obvious fluorescence enhancement. Moreover, the intensity of the fluorescence emission of chemosensors increases significantly in the presence of Zn^2＋ and Cd^2＋. The fluorescent chemosensors with different polyamine as receptors show diverse affinity abilities to the transition metal ions and signal the receptor-metal ion interaction by the intensity change of fluorescence emission.

Synthesis of Porphyrin-Appended Pyridine as a Fluorescent Chemosensor for Cd（Ⅱ） and Hg（Ⅱ）

In this research, specific molecular sensors are classified according to the type of receptor-cation interaction, that is ligand-metal interactions. Receptors are based on a multidentate protoporphyrin-appended pyridine platform, which leaves at least a vacant coordination site for the incoming metal ions. A protoporphyrin-appended pyridine, 2,5-pyridine dicarboxyamidyl-8,13-bis（vinyl）-3,7,18,17-tetramethyl-21 H, 23 H-porphyrin（P-PTP）, was designed and synthesized. Its application as potential fluoroionophore for recognition of cadmium and mercury ions is reported. P-PTP shows chelation-enhanced fluorescence effect with Cd（Ⅱ） and Hg（Ⅱ） via the interruption of photoinduced electron transfer （PET） process, which has been utilized as the basis of the fabrication of the metal ions-sensitive fluorescent chemosensor. The analytical performance characteristics of the proposed Cd（Ⅱ）- and Hg（Ⅱ）- sensitive chemosensors were investigated. It shows a linear response toward Cd（Ⅱ） and Hg（Ⅱ） in the concentration range of 1.0×10-3 to 1.0×10-7 M with a limit of detection of 1.0×10-7 M and 0.5×10-7M for Cd（Ⅱ） and Hg（Ⅱ）, respectively. The chemosensor shows good selectivity for Cd（Ⅱ） over a large number of other transition metal ions, i.e., Cu（Ⅱ）, Zn（Ⅱ） and mixed metal ions.