论文期刊

Modification-free colorimetric and visual detection of Hg 2+ based on the etching from core-shell structural Au-Ag nanorods to nanorices




作者: Ying Qi, Jing Zhao, Guojun Weng, Jianjun Li, Jian Zhu ∗ , Junwu Zhao ∗
发表/完成日期: 2018-04-09
期刊名称: Sensors and Actuators B: Chemical
期卷: 267 (2018)
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论文简介
A simple
and rapid colorimetric approach for Hg 2+ detection is achieved by etching silver-coated gold
nanobipyramids (Au NBs@Ag nanoparticles) based on the redox reaction between Hg 2+ and silver
nanoshell
of the Au NBs@Ag nanoparticles. The decrease of the silver nanoshell thickness leads to first
blue
shift and then red shift of the longitudinal localized surface plasmon resonance (LSPR) peak and
accompanies
a vivid color change. The blue shift is more suitable for colorimetric detection which has
the
obvious multicolor change from yellow-green to green and then to blue-gray; and could be employed
to
quantitatively detect the concentrations of Hg 2+ . This nanoprobe with the longitudinal LSPR peak at
730
nm exhibits a linear range of 0.1–20 ?M with a limit of detection (LOD) of 22 nM based on blue shift
and
has the most obvious color change with the lowest LOD of 0.8 ?M by direct observation. In this case,
the Au NBs@Ag nanoparticles are gradually etched from the nanorods to nanorices as the Hg 2+ concen-
tration
increases. Compared with other techniques, this method could avoid tedious procedures and is
time-saving.
Furthermore, this nanoprobe has good selectivity, and is well demonstrated in real samples
with
satisfied results.
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