Critical Addition Point-Based Trace Sensing of Hg²+ Through Surface Plasma Polaritons Properties Analysis of Ag Nanoparticles

In this work, we synthesize and functionalize Ag nanoparticles (NPs) with Sodium tripolyphosphate in one pot. Due to P
₃
O
₁₀
^5-
_10-
AgNPs aggregation in the presence of mercury, colorimetric detection with naked eye realize, the limit of detection is 1μmol·L
^-1
. Based on one critical additional point with 3μmol·L
^-1
of Hg
²⁺
added, trace sensing of mercury can be performed through absorption spectra analysis, the limit of detection reaches 1nmol·L
^-1
. The TEM image and EDS test tell the mechanism, where the aggregating behavior of P
₃
O
_-10-
^5-
AgNPs in the presence of Hg
²⁺
is different from that of Cr
³⁺
and Mn
²⁺
. Also, this method possesses high selectivity. This work may pave a facile way in mercury detection sensors.