Abstract
Development of selective colorimetric detectors that can use green-fabricated silver nanoparticles’ (
AgNPs
) with localized surface plasmon resonances (
LSPRs
) to rapidly, simply, and selectively detect
Hg
II
ions was undertaken in this study. Onion extract was used for synthesising photo-induced green crystalline silver nanoparticles (
NPs
). The formation of nanoparticles is enhanced when ultrasound irradiation is present; bioligands could serve as stabilizing and reducing agents. Different methods of measurement, including UV-Vis,
TEM
,
SEM
/
EDAX
,
FT
−
IR
, and
XRD
, are effective for characterization of nanoparticles. The spherical nature of green-fabricated
AgNPs
is confirmed by TEM. High-density, spherical, and uniformly formed silver nanoparticle shapes were found in silver nanoparticle SEM images. The arrangement of
AgNPs
in the form of face-centered cubic structures was confirmed by
XRD
patterns. The formation of impurity-free
AgNPs
was confirmed using the
EDAX
analysis results.
Hg
2
+
with excellent sensitivity was sensitively and selectively detected by employing green-synthesized silver nanoparticles. The reduction of
Ag
(1) to
Ag
(0) was confirmed by a slight increase in
Hg
(II) concentration and progressive reduction of green-synthesized
AgNPs
, whose absorbance changed abruptly. The reduction of
LSPRs
by the phosphate buffer medium enables
AgNPs
to sensitively and selectively detect
Hg
2
+
ions by providing good environment. Besides, a selective, sensitive, simple, and rapid method that is proposed for detecting
Hg
(II) ions in samples of water is presented in the study. Harmful mercury ions in real samples of water (tap and ground water) can colorimetrically and selectively be detected using the
AgNPs
. The results showed an RSD of below 6% and over 92% of good recovery.