Highly Sensitive Colorimetric Assay for Determining Fe³⁺ Based on Gold Nanoparticles Conjugated with Glycol Chitosan

Table 1

Determination of Fe³⁺ ions in spiked tap water, pond water, and iron supplement samples analyzed by the GC-AuNP probe and AAS.

Amount of Fe^3+ added to real samples ( = 7)
Sample	Present probe					AAS
	Added amount; (nM)	Detected amount; (nM)	Coefficient of variation; (%)	Recovery; (%)	LOD; (nM)	Detected amount; (nM)
Tap water	60.0	60.4 ± 0.745	1.23	100.7 ± 1.24	11.3	60.0 ± 1.00 × 10^−2
	1.80 × 10^2		0.261	100.6 ± 0.262
Pond water	60.0	60.3 ± 0.429	0.711	100.6 ± 0.715	29.2	60.0 ± 1.00 × 10^−2
	1.80 × 10^2		0.229	100.1 ± 0.229
Iron supplement	60.0	60.4 ± 0.629	1.04	100.7 ± 1.05	46.0	60.0 ± 1.00 × 10^−2
	1.80 × 10^2		0.589	99.6 ± 0.587