Visualizing Zn ²⁺ in Living Whole Organism <i>Artemia</i> by a Natural Fluorimetric Intermediate Siderophore

Abstract

Abstract Aeruginic acid (H 2 L), a weakly fluorescent natural ionophore, was synthesized via one‐pot mechanochemical grinding at room‐temperature. This sulfur containing intermediate siderophore showed unique specificity towards Zn 2+ in 100% water at physiological pH even in presence of other challenging metal ions particularly, paramagnetic metal ions such as Fe 3+ , Co 2+ , Ni 2+ , and Cu 2+ . H 2 L also displayed a naked eye observable instant color change under UV light in presence of Zn 2+ , in aqueous solution and in solid phase as well. The receptor H 2 L with 49 nM limit of detection, upon excitation at 360 nm, reversibly binds one equivalent Zn 2+ as evidenced from Job's plot, ESI‐MS, and 1 H NMR spectroscopy. Being fully water soluble, non‐toxic, and permeable in nature, this natural ionophore can visualize Zn 2+ in the gastrointestinal tract of live whole brine shrimp Artemia . We are not aware of any report on bio‐imaging of Zn 2+ in living organism.