Maximizing surface-enhanced Raman scattering sensitivity of surfactant-free Ag-Fe3O4 nanocomposites through optimization of silver nanoparticle density and magnetic self-assembly

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal

30 Scopus Citations
View graph of relations

Author(s)

Detail(s)

Original languageEnglish
Article number124305
Journal / PublicationJournal of Applied Physics
Volume114
Issue number12
Online published25 Sep 2013
Publication statusPublished - 28 Sep 2013
Externally publishedYes

Abstract

Magnetic composite nanomaterials consisting of more than two functional constituents have been attracting much research interests due to the realization of multiple functionalities in a single entity. In particular, integration of ferromagnetic oxides and noble metal nanoparticles (NPs) in composites results in simultaneous magnetic activity and optical response where the optical property of the whole system could be modulated by application of an external magnetic field. In this work, we prepared Ag NPs-coated Fe3O 4 microspheres as a novel surfactant-free surface-enhanced Raman scattering (SERS) substrate through a solid-phase thermal decomposition reaction. The SERS sensitivity of the fabricated nanocomposites is maximized by adjusting the size and density of Ag NPs supported on the Fe3O 4 microspheres and further increased by magnetic-field-directed self-assembly of the composite substrates, with both effects attributed to the efficient generation of plasmonic near-field "hot" spots. At the optimal conditions, the prepared substrate is capable of detecting rhodamine 6G molecules at a concentration down to 10-12 M, thus demonstrating the great potential of using bifunctional nanocomposites as an excellent candidate for ultra-high sensitive Raman spectroscopy and biosensors. We also reveal the underlying mechanisms responsible for the observed SERS enhancements through full-wave numerical simulations.  

Citation Format(s)

Maximizing surface-enhanced Raman scattering sensitivity of surfactant-free Ag-Fe3O4 nanocomposites through optimization of silver nanoparticle density and magnetic self-assembly. / Bao, Zhi Yong; Dai, Jiyan; Lei, Dang Yuan; Wu, Yucheng.

In: Journal of Applied Physics, Vol. 114, No. 12, 124305, 28.09.2013.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal