Compartmentalization of gold nanoparticle clusters in hollow silica spheres and their assembly induced by an external electric field

JOURNAL OF COLLOID AND INTERFACE SCIENCE

卷:566

Article

Watanabe, Kanako¹  Welling, Tom A. J.²  Sadighikia, Sina²  Ishii, Haruyuki³  Imhof, Arnout²  van Huis, Marijn A.²  van Blaaderen, Alfons²  Nagao, Daisuke¹ 

[1] Tohoku Univ, Dept Chem Engn, Aoba Ku, 6-6-07 Aoba, Sendai, Miyagi 9808579, Japan

[2] Univ Utrecht, Debye Inst Nanomat Sci, Soft Condensed Matter, Princetonplein 5, NL-3584 CC Utrecht, Netherlands

[3] Yamaguchi Univ, Dept Sustainable Environm Engn, 2-16-1 Tokiwadai, Ube, Yamaguchi 7550097, Japan

关键词: Plasmonic nanoparticles;    Nanoparticle clusters;    Plasmonic properties;    surface-enhanced Raman scattering;    Hollow particles;    Particle assembly;   

DOI  :  10.1016/j.jcis.2020.01.094

来源: Elsevier

【 摘 要 】

Assembly of plasmonic nanoparticle clusters having hotspots in a specific space is an effective way to efficiently utilize their plasmonic properties. In the assembly, however, bulk-like aggregates of the nanoparticles are readily formed by strong van der Waals forces, inducing a decrease of the properties. The present work proposes an advanced method to avoid aggregation of the clusters by encapsulating into a confined space of hollow silica interior. Hollow spheres incorporating gold nanoparticle clusters were synthesized by a surface-protected etching process. The observation of inner nanoparticles with liquid cell transmission electron microscopy experimentally proved that the nanoparticles moved as a cluster instead of as dispersed nanoparticles within the water-filled hollow compartment. The hollow spheres incorporating the nanoparticle clusters were assembled in the vicinity of electrodes by application of an external AC electric field, resulting in the enhancement of Raman intensities of probe molecules. The nanoparticle-cluster-containing hollow spheres were redispersed when the electric field was turned off, showing that the hollow silica spheres can act as a physical barrier to avoid the cluster aggregation. The Raman intensities were reversibly changed by switching the electric field on and off to control the assembled or dispersed states of the hollow spheres. (C) 2020 Elsevier Inc. All rights reserved.

【 授权许可】

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