Rapid Synthesis of Monodispersed Au-Ag Alloy Nanosponges Using Selective Laser Melting and Dealloying for Sensitive Near-Infrared Surface-Enhanced Raman Scattering
Rapid Synthesis of Monodispersed Au-Ag Alloy Nanosponges Using Selective Laser Melting and Dealloying for Sensitive Near-Infrared Surface-Enhanced Raman Scattering
复制标题
利用选择性激光熔化和脱合金快速合成单分散金银合金纳米海绵，用于灵敏的近红外表面增强拉曼散射
DOI：
10.1088/1361-6528/ac2a82
复制
发表时间：
2021
期刊：
影响因子：
3.5
通讯作者：
Guihua Jiang
中科院分区：
文献类型：
--
作者：
Hua Wen;Lifeng Hang;Lianbao Liang;Wuming Li;Guihua Jiang
研究了一种采用选择性激光辐照熔融和化学合金化工艺快速合成具有高密度近红外表面增强拉曼散射（NIR-SERS）“热点”的单分散金银合金纳米海绵（NSs）的方法。通过快速激光辐照，在2分钟内将Au@ Ag核壳纳米球原位转化为固体合金Au-Ag纳米球。经化学合金化处理后，合金Au-Ag纳米球转化为Au-Ag合金NSs。与传统的热退火不同的是，它可以有效地避免纳米颗粒之间的热融合，并保持合金Au-Ag纳米球和NSs的高单分散性。重要的是，由于纳米孔（孔径小于10 nm）中的强等离子体耦合，所获得的Au-Ag合金NSs在可见光至近红外区域（500-1200 nm）表现出广泛而强烈的局部表面等离子体共振吸收。可接近的开放结构和高密度的“nir热点”使金-银合金NSs衬底对4-氨基噻吩的NIR-SERS检测具有优异的灵敏度，增强因子为~ 10.7。这项工作不仅为快速制备生物传感用NIR-SERS底物提供了一条简单的途径，而且可能为利用其他元素制备海绵状纳米结构开辟了新的途径。
We developed a rapid synthesis method for monodispersed Au–Ag alloy nanosponges (NSs) with high density of'hotspots' for near-infrared surface enhanced Raman scattering (NIR-SERS) by a selective laser-irradiation melting and chemical dealloying process. Au@ Ag core–shell nanocubes were first in situ converted into solid alloyed Au–Ag nanospheres by a rapid laser irradiation igniting quick fusion and quenching process within two minutes. The alloyed Au–Ag nanospheres transformed into Au–Ag alloy NSs after treated by a chemical dealloying process. Different from traditional thermal annealing, it thus can effectively avoid the heat fusion between nanoparticles, and maintain the alloyed Au–Ag nanospheres and NSs in high monodispersity. Importantly, due to the strong plasmonic coupling in nanopores (pore size less than 10 nm), the obtained Au–Ag alloy NSs show a broad and intense localized surface plasmon resonances absorption ranging from visible to near-Infrared region (500–1200 nm). The accessibly open structures for absorbing targets and high-density of'NIR-hotspots' endow the Au–Ag alloy NSs substrate with superior sensitivity in NIR-SERS detection of 4-aminothiophenol with an enhancement factor of∼ 10 7. This work not only provides a simple pathway for rapid preparation of NIR-SERS substrate for biosensing, but also might open up a new horizon for fabricating spongy nanostructures with other elements.