Tooba et al. (2026) develop a silver nanoparticle (AgNPs)-based colorimetric sensor for the detection of mercury(II) (Hg2+) in water samples. The method relies on aggregation-induced color change of AgNPs in the presence of Hg2+, enabling naked-eye or spectrophotometric quantification without specialized instrumentation.
Key numbers
Limit of detection (LOD): 37.7 nM Hg2+, equivalent to approximately 7.5 µg/L (7.5 ppb). This is above the WHO drinking water guideline of 6 µg/L for total mercury, meaning the method as reported would not reliably detect mercury at the guideline level.
Validated in river water and tap water matrices. No food matrix validation reported.
Methods (brief)
AgNPs colorimetric platform. Aggregation mechanism. Spectrophotometric readout. Simple, low-cost, field-deployable concept but LOD of 37.7 nM is not competitive with ICP-MS for regulatory compliance testing (ICP-MS LODs for Hg in water are typically <0.01 µg/L). Suitable for screening applications where positive samples exceed 7–8 µg/L.
CC BY license.
Implications
Testing: Colorimetric AgNPs platforms for Hg2+ are well-established in the literature; this paper contributes a new synthesis route or optimization. The LOD of 37.7 nM is not food-matrix-applicable but the approach is relevant to field screening in water monitoring.