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

Table 1

Concentrations of Hg²⁺ ions measured by the PEI-AuNP colorimetric probe and DMA in tap water, pond water, tuna fish, and bovine serum samples spiked with Hg²⁺ ions.

Content of Hg^2+ added to various samples (n = 7)
PEI-AuNP probe						DMA
Sample	Added amount (μM)	Detected amount (μM)	Coefficient of variation (%)	Recovery (%)	LOD (nM)	Detected amount (μM)
Tap water	0.150	0.149 ± 1.53 × 10^−4	0.102	99.9 ± 0.102	1.72	0.153
	0.500	0.499 ± 0.0101	2.03	99.9 ± 2.03		0.505
Pond water	0.150	0.150 ± 6.92 × 10^−4	0.460	100.2 ± 0.461	1.80	0.156
	0.500	0.500 ± 3.41 × 10^−3	0.682	100.1 ± 0.683		0.504
Tuna fish	0.150	0.149 ± 7.09 × 10^−4	0.473	99.8 ± 0.473	2.00	0.152
	0.500	0.503 ± 0.0155	3.08	100.6 ± 3.10		0.504
Bovine serum	0.150	0.150 ± 6.43 × 10^−4	0.427	100.1 ± 0.428	1.95	0.155
	0.500	0.503 ± 7.68 × 10^−3	1.52	100.7 ± 1.53		0.507