Polyethylenimine-interlayered core-shell-satellite 3D magnetic microspheres as versatile SERS substrates

Chongwen Wang, Ping Li, Junfeng Wang, Zhen Rong, Yuanfeng Pang, Jiawen Xu, Peitao Dong, Rui Xiao, Shengqi Wang*

*此作品的通讯作者

科研成果: 期刊稿件文章同行评审

80 引用 (Scopus)

摘要

Precise fabrication of subtle nanogaps amid individual nanoparticles or between adjacent ones to obtain the highest SERS enhancement is still a challenge. Here, we reported a novel approach for fabricating core-shell-satellite 3D magnetic microspheres (CSSM), that easily form a porous 1.5 nm PEI interlayer to accommodate molecules and create sufficient hotspots between the inner Fe3O4@Ag core and outer assembled Au@Ag satellites. Experiments and finite-difference time-domain (FDTD) simulation demonstrated that the enhancement factor (EF) was about 2.03 × 108 and 6.25 × 106, respectively. In addition, the micro-scale magnetic core endowed the CSSM with a superior magnetic nature, which enabled easy separation and further enhanced Raman signals due to enrichment of targeted analytes and abundant interparticle hotspots created by magnetism-induced aggregation. Our results further demonstrated that the CSSM is expected to be a versatile SERS substrate, which has been verified by the detection of the adsorbed pesticide thiram and the non-adsorbed pesticide paraquat with a detection limit as low as 5 × 10-12 M and 1 × 10-10 M, respectively. The novel CSSM can overcome the long-standing limitations of SERS for the trace characterization of various analytes in different solutions and promises to transform SERS into a practical analytical technique.

源语言英语
页(从-至)18694-18707
页数14
期刊Nanoscale
7
44
DOI
出版状态已出版 - 28 11月 2015
已对外发布

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