Sun Mei, Zhao Aiwu, Wang Dapeng, Wang Jin, Chen Ping, Sun Henghui
Institute of Intelligent Machines, Chinese Academy of Sciences, hefei, CHINA.
Institute of Intelligent Machines, Chinese Academy of Sciences , hefei, CHINA.
Nanotechnology. 2018 Feb 9. doi: 10.1088/1361-6528/aaae42.
As a novel SERS nanocomposities, cube-like Fe3O4@SiO2@Au@Ag magnetic nanoparticles have been synthesized for the first time. Cube-like α-Fe2O3 NPs with uniform size can be achieved by optimizing reaction temperature and time. Firstly, the cube-like Fe3O4@SiO2 with good dispersity were achieved by calcining α-Fe2O3@SiO2 NPs in hydrogen atmosphere at 360 °C for 2.5 h, followed by self-assembling PEI shell via sonication. Furthermore, the Au@Ag particles can be densely assembled on the Fe3O4@SiO2 NPs to form the Fe3O4@SiO2@Au@Ag composite structure via strong Ag-N interaction. The obtained nanocomposites exhibit an excellent surface-enhanced Raman (SERS) behavior, reflected from low detection of limit (p-ATP) at 5×10-14 M level. Moreover, these nanocubes are used for detection of thiram and the detection limit can reach up to 5×10-11 M, while the rule of U.S. Environmental Protection Agency specifies that the residue in fruit must be lower than 7 ppm. Hence, the resulting substrate with high SERS activity has great practical potential applications in rapid detection of chemical, biological and environment pollutants with a simple portable Raman instrument at trace level.
作为一种新型的表面增强拉曼散射（SERS）纳米复合材料，首次合成了立方状的Fe3O4@SiO2@Au@Ag磁性纳米粒子。通过优化反应温度和时间，可以得到尺寸均匀的立方状α-Fe2O3纳米粒子。首先，将α-Fe2O3@SiO2纳米粒子在360℃氢气气氛中煅烧2.5小时，得到分散性良好的立方状Fe3O4@SiO2，然后通过超声处理自组装PEI壳层。此外，Au@Ag粒子可以通过强Ag-N相互作用密集地组装在Fe3O4@SiO2纳米粒子上，形成Fe3O4@SiO2@Au@Ag复合结构。所制备的纳米复合材料表现出优异的表面增强拉曼散射（SERS）行为，在5×10-14 M水平下对限定量（p-ATP）的检测下限较低即可体现。此外，这些纳米立方体用于检测福美双，检测限可达5×10-11 M，而美国环境保护局规定水果中的残留量必须低于7 ppm。因此，所制备的具有高SERS活性的基底，在使用简单便携式拉曼仪器对化学、生物和环境污染物进行痕量快速检测方面具有巨大的实际潜在应用价值。
