Formation of PdPt alloy nanodots on gold nanorods: tuning oxidase-like activities via composition.
Formation of PdPt alloy nanodots on gold nanorods: tuning oxidase-like activities via composition.
复制标题
DOI：
10.1021/la104566e
复制
发表时间：
2011-02
期刊：
影响因子：
--
通讯作者：
Ke Zhang;Xiaona Hu;Jianbo Liu;Jun-Jie Yin;S. Hou;T. Wen;Weiwei He;Yinglu Ji;Yuting Guo
中科院分区：
文献类型：
--
作者：
Ke Zhang;Xiaona Hu;Jianbo Liu;Jun-Jie Yin;S. Hou;T. Wen;Weiwei He;Yinglu Ji;Yuting Guo
利用Pt的岛状生长模式在金纳米棒上形成PdPt合金纳米点（Au@PdPt NRs）。Pd/Pt比值在0.2 ~ 5范围内可调的合金纳米点均匀分布在Au NR表面。纳米点壳层的形成导致了Au纳米棒的纵向表面等离子体共振（LSPR）带的红移和展宽。Au@PdPt合金纳米棒在温和条件下对常用显色底物的氧化具有催化活性，表明其是一种新型的氧化酶模拟物。对抗坏血酸（AA）和3，3 ′，5，5 ′-四甲基联苯胺（TMB）的氧化以及对硝基苯酚的还原反应，观察到了组成依赖的催化活性。对于AA和TMB，催化活性在较低的Pd/Pt比下快速增强，并且在较高的Pd/Pt比下趋于饱和。对于对硝基苯酚的还原，由于Pd的催化活性较高，催化活性与Pd/Pt比呈良好的线性关系。总之，Pd和Pt的适当合金化提供了定制催化活性的有效途径。有趣的是，合金纳米点还可以催化溶解氧将Fe（II）氧化为Fe（III）。因此，基于TMB和Fe（II）的竞争性氧化，可以实现后者的选择性检测。
The island growth mode of Pt was employed to guide the forma-tion of PdPt alloy nanodots on gold nanorods (Au@PdPt NRs). Well-defined alloy nanodots, with tunable Pd/Pt ratios from 0.2 to 5, distribute homogeneously on the surface of the Au NR. Formation of nanodots shell leads to the red-shift and broadening of the longitudinal surface plasmon resonance (LSPR) band of the Au NRs. The Au@PdPt alloy NRs exhibit catalytic activity toward oxidation of often-used chromogenic substrates by dissolved oxygen under mild conditions, suggesting a new type of oxidase mimics. Composition dependence catalytic activity is observed for the oxidation of ascorbic acid (AA) and 3,3',5,5'-tetramethylbenzidine (TMB) and for the reduction of p-nitrophenol. For AA and TMB, catalytic activity enhances quickly at lower Pd/Pt ratios and tends to saturate at higher Pd/Pt ratios. For p-nitrophenol reduction, catalytic activity shows a nice linear relationship with Pd/Pt ratio owing to much higher catalytic activity of Pd. In conclusion, proper alloying of Pd and Pt presents an effective route to tailor the catalytic activity. Interesting, alloy nanodots can also catalyze the oxidation of Fe (II) to Fe (III) by dissolved oxygen. Thus, based on the competitive oxidation of TMB and Fe (II), selective detection of the latter can be achieved.