Magnetic field modulated SERS enhancement of CoPt hollow nanoparticles with sizes below 10 nm
Magnetic field modulated SERS enhancement of CoPt hollow nanoparticles with sizes below 10 nm
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磁场调制 SERS 增强尺寸低于 10 nm 的 CoPt 空心纳米粒子
DOI：
10.1039/c8nr03781g
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发表时间：
2018
期刊：
影响因子：
6.7
通讯作者：
Wang Rongming
中科院分区：
文献类型：
--
作者：
Wang Yinong;Liu Qing;Sun Yinghui;Wang Rongming
众所周知，当与Au、Ag和Cu相比时，Pt在可见光谱中显示出弱得多的等离子体效应。因此，通过在可见光谱中具有小于10 nm的尺寸的Pt纳米颗粒实现有效的光吸收仍然是一个挑战。提高光吸收的一种可能的方法是制备Pt基双磁性纳米颗粒。此外，如果施加外部磁场，则电场和磁场两者的协同效应可以提供足够的Sers增强。本文在室温下，在溶液中合成了尺寸小于10 nm，壳层尺寸约为12 nm的CoPt空心纳米粒子（NPs）。纳米颗粒具有高的表面积与体积比和优异的结构稳定性。空心纳米粒子表现出增强的光吸收，其特征在于与4-巯基苯甲酸（4-MBA）作为尖端分子的表面增强拉曼散射（Sers）。值得注意的是，这些合金纳米颗粒的Sers增强可以通过使用外部磁场来调谐。这些中空纳米颗粒和银膜基板之间的协同光学效应。因此，CoPt空心纳米颗粒显示出作为Sers基底的前景和在光学增强中的其他应用的潜力。
It is well known that Pt shows much weaker plasmonic effects in the visible spectrum when compared to Au, Ag and Cu. Therefore, the realization of efficient optical absorption by Pt nanoparticles with sizes below 10 nm in the visible spectrum remains a challenge. One possible way to enhance the optical absorption is to prepare Pt-based bimetallic magnetic nanoparticles. Furthermore, if an external magnetic field is applied, the synergistic effect of both electric and magnetic fields may provide sufficient SERS enhancement. In this paper, CoPt hollow nanoparticles (NPs) with sizes below 10 nm and ultrathin shells (∼2 nm) were synthesized in solution, at room temperature. The NPs have high surface-to-volume ratios and excellent structural stability. The hollow NPs exhibited enhanced light absorption characterized by surface-enhanced Raman scattering (SERS) with 4-mercaptobenzoic acid (4-MBA) as tip molecules. It is noted that the SERS enhancement of these alloyed NPs can be tuned by using an external magnetic field. A synergistic optical effect between these hollow NPs and the Ag film substrate is obtained. Hence, CoPt hollow NPs show promise as SERS substrates and potential for other applications in optical enhancement.