A Highly Sensitive and Selective Colorimetric Hg²⁺ Ion Probe Using Gold Nanoparticles Functionalized with Polyethyleneimine

Table 3

Comparison of previously reported instrumental methods and nanoparticle assay methods proposed for the detection of Hg²⁺.

	Sensing principles	Matrices	LOD	Reference
Instruments
DMA	—	River sediment, bovine liver, tomato leaves, spinach leaves, sewage sludge, mussel tissue, fish tissue, fish protein	1.04 μM	[8]
IC	IC	Tunny fish, oyster, and trumpet	0.5 μM	[9]
HPLC	SPE	Tap water, river water, sea water, and coal-washing waste water	14.9 nM	[10]
HPLC	SAX	Drinking water, lake water, river water, tap water, and sea water	0.8 nM	[11]
Functionalized nanoparticles
AuNRs	Colorimetric	—	14.9 nM	[12]
CNPs	Fluorometric	Tap water and commercial bottled mineral water	10 nM	[13]
AgNPs	Colorimetric	Tap water	1 nM	[14]
AgNPRs	Colorimetric	Lake water and tap water	3.0 nM	[15]
Lysine–AuNPs	Colorimetric	Tap water	2.9 nM	[16]
DDTC–AuNPs	Colorimetric	Drinking water	2.9 nM	[17]
TCA–AuNCs	Colorimetric	Tap water and lake water	0.5 nM	[18]
PEI–AuNPs	Colorimetric	Tap water and pond water	1.72 nM	This study

SPE: solid phase extraction; SAX: strong anion exchange column; DDTC: diethyldithiocarbamate; TCA: thiocyanuric acid.