Author/Authors :
Li, Lihua Department of Pharmacy - Wannan Medical College, People’s Republic of China , Feng, Dexiang Department of Pharmacy - Wannan Medical College, People’s Republic of China , Fang, Xian Anhui Normal University, People’s Republic of China , Han, Xiaowei Anhui Normal University, People’s Republic of China , Zhang, Yuzhong Anhui Normal University, People’s Republic of China
Abstract :
In this work, we have developed a novel visual
Hg2? sensor in aqueous solution using unmodified Au@Ag
core–shell nanoparticles at room temperature, based on a
redox reaction between Ag-shell and Hg2?. The prepared
Au@Ag core–shell nanoparticles exhibited good monodispersity.
In the presence of Hg2?, Hg2? was reduced into
Hg (0) by Ag-shell, and deposited on the surface of Aucore
to form Au–Hg alloys and caused nanoparticles
aggregation, leading to the color changes of the solution
from yellow to purplish red, and the surface plasmon resonance
spectra of Au@Ag core–shell nanoparticles red
shift. Under the optimal conditions, the visual sensor could
selectively detect Hg2? as low as 0.4 lM with the naked
eye and 5.0 nM by UV–vis spectra analysis methods. The
designed sensor had several advantages: (1) the nanoparticles
surface need not be functionalized. (2) The color
change of the solution was in 2 s and could easily be
observed with naked eyes. The visual sensor had been
applied to detection of Hg2? in tap and lake water, which
obtained satisfied result.
