以PAMAM树形分子为模板制备Pd纳米簇合物

以酯端基聚酰胺-胺树形分子(PAMAM)为模板在甲醇溶剂中制备了Pd纳米簇合物. 采用紫外-可见分光光度法和红外光谱法研究了Pd²⁺与树形分子的作用机理, 结果表明, Pd²⁺与树形分子内部胺基基团(主要为叔胺基)产生了络合作用. 采用硼氢化钠还原法制备了树形分子包裹的、粒径为2 nm的球形面心立方Pd纳米簇合物. 紫外-可见吸收光谱研究结果表明, Pd²⁺与树形分子的摩尔比越小, 生成的纳米簇合物尺寸越小; 由于高代数树形分子具有封闭结构, 且其内部配体数目较多, 采用较高代数的树形分子(5.5代)比低代数(3.5代)更有利于得到尺寸小、分散性较好的Pd纳米簇合物.     

铁氰化钴/树状高分子修饰电极免标记法检测基因突变

利用铁氰化钴/树状高分子(CoHCF/PAMAM)复合材料修饰玻碳电极(GCE), 制备了免标记检测基因突变的新型DNA电化学传感器. 传感器中树状高分子层明显增加了单链DNA探针的固定量, 铁氰化钴层增大了鸟嘌呤的氧化信号, 该传感器可以灵敏识别单碱基错配的基因序列, 具有良好的选择性和灵敏度. 在7.6×10^-11～3.05×10^-8 mol/L浓度范围内, 鸟嘌呤(G)的氧化峰电流差值与突变基因浓度呈良好的线性关系, 检出限为1.0×10^-11 mol/L(S/N=3).     

Metal adsorption properties of multi-functional PAMAM dendrimer based gels

Metal adsorption studies are getting important and there are many functional adsorbents developed recently. Here, we report the synthesis of multifunctional PAMAM G2 (polyamidoamine) possessing methacryl, amine, hydroxyl and phosphonate groups used in free radical curing gel formulations. UV curable gel is conducted in the presence of acrylamide, bisacrylamide, and polyethylene glycol diacrylate. Adsorption study of the resulting novel sorbents (gels) are carried out with a series of metals. Through a comprehensive study, structure–property relationship of the series gels is conducted by using different amount of amine, hydroxyl, and/or phosphonate ester groups on the PAMAM G2. Selected metals are Cr³⁺, Fe³⁺, Ni²⁺, Cu²⁺, Ag⁺, and Cd²⁺ within a series of hard, intermediate, and soft ionic species. Adsorption study is carried out in pure water environment at neutral pH. Metal ions removal percentages and adsorption capacities of gel adsorbents are calculated by using atomic absorption spectroscopy. There is relationship between the overall functional groups presence in gel formulation and swelling densities for removing the metal ions. Introducing dendrimer into the gel formulation enhanced the metal ions adsorption against to Bare GEL formulation which do not possess dendrimer units. Consequently, the maximum removal efficiency has been obtained for Cr³⁺ and Fe³⁺.