论文期刊

SERS detection of glucose using graphene-oxidewrapped gold nanobones with silver coating




作者: Jian Zhu, * H.F. Du, Qi Zhang, Jing Zhao, G.J. Weng, J.J. Li, J.W. Zhao*
发表/完成日期: 2019-02-12
期刊名称: Journal of Materials Chemistry C
期卷:
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论文简介
In this work, we prepared graphene oxide (GO)-decorated silver-coated gold nanobones (AuNBs@
Ag@GO) for obtaining optimal surface-enhanced Raman scattering (SERS) activity. 4-Mercaptobenzoic
acid (4-MBA) was adsorbed on the interface between gold and silver to provide more space for GO
decoration on the outer surface of silver. Silver was deposited on the middle and end surfaces of the
gold nanobones (AuNBs) with negative curvature, which resulted in stubby bimetallic nanocuboids
inducing transverse surface plasmon resonance (SPR); the intermediate SPR merged into a new plasmon
resonance. The SERS activity of silver-coated gold nanobones (AuNBs@Ag) changed non-monotonically
with an increase in the silver coating, which reached up to 8 times larger than that of bare AuNBs. This
is better performance than that of silver-coated gold nanorods (AuNRs@Ag). GO hybridized with
AuNBs@Ag by electrostatic adherence could further improve the SERS activity of AuNBs@Ag, and the
concentration of GO was adjusted for the best SERS performance, which was 4 times higher than that
of naked AuNBs@Ag. AuNBs@Ag@GO can be used as a SERS substrate to detect glucose in urine. The
mechanism is that the higher concentration of liquid glucose induced a large density of coverage,
forming a glucose partition layer on the AuNBs@Ag@GO substrate: with an increase in the glucose
concentration, the thickness of the glucose partition layer increased. This reduced the intensity of
incident light and resulted in a decrease in the Raman signal of 4-MBA. Moreover, the strong SERS
activity of the AuNBs@Ag@GO substrate can provide a wider space to achieve a lower limit of detection
(LOD) value for glucose. The intensity of the characteristic Raman peak at 1585 cm1 linearly decreased
with an increase in the glucose concentration in the range of 10–107 nmol L1 with a low LOD value
(S/N = 3) of 2.61 nmol L1
. At the same time, it is confirmed that the SERS substrate can be selective
and reliable and shows promising potential and broad applications in glucose detection.