Optical mesosensor for capturing of Fe(III) and Hg(II) ions from water and physiological fluids

This study developed a pH-dependent mesosensor for the optical and selective removal of Hg²⁺ ions from drinking water and physiological fluids. The fine-tuned surface patterning of the mesoscopic solid aluminosilica scaffolding architectures, which was achieved using a dispersible active agent such as a cationic surfactant, resulted in the dense immobilization of addressable diphenylcarbazide chelating agent. These mesosensor responses can be triggered by the target species and can transduce measurable optical signals under synergistic pH conditions, thus enabling the binding of Fe³⁺ and Hg²⁺ metals into a hydrophobic chelating pocket to be simulated. Results verified the one-step removal and optical adsorption efficiency of ultra-trace, wide-range (0.001 mg dm^-3 to 2.0 mg dm^-3) concentrations of Fe³⁺ and Hg²⁺ ions into the interior pore surface coverage of the DPC-modified mesosensor from drinking water. Importantly, the mesosensor can be repeatedly recycled without damaging the unique mesostructures. Furthermore, the hemolysis test of Hg²⁺ ion toxicity in red blood cells (RBCs) and the counteraction effect of the phosphatidylserine (Ptd-L-Ser) receptor exposure of RBCs were also investigated in a physiological system such as human blood. Results indicated that the strong binding site-metal interaction enabled the remarkably selective removal of Hg²⁺ ions from physiological fluids.