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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 x 10(8) and 6.25 x 10(6), 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 x 10(-12) M and 1 x 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.
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NANOSCALE
ISSN: 2040-3364
Year: 2015
Issue: 44
Volume: 7
Page: 18694-18707
6 . 7 0 0
JCR@2022
ESI Discipline: PHYSICS;
ESI HC Threshold:190
JCR Journal Grade:1
CAS Journal Grade:2
Cited Count:
WoS CC Cited Count: 79
SCOPUS Cited Count: 81
ESI Highly Cited Papers on the List: 0 Unfold All
WanFang Cited Count:
Chinese Cited Count:
30 Days PV: 1
Affiliated Colleges: