Colorimetric Hg²⁺ Sensing in Water: From Molecules toward Low-Cost Solid Devices

A new colorimetric molecular sensor allowing for cheap, fast, sensitive, and highly selective naked-eye detection of Hg²⁺ in water is described. This molecule combines a 1,8-diaminoanthraquinone signaling subunit and phosphonic acid esters that confer the water solubility to the dye (R = H). A ready-to-use colorimetric solid sensor was obtained by incorporating an amphiphilic analog (R = OC₁₂H₂₅) exhibiting similar binding properties and optical responses in an agarose film