Visualizing Zn2+ in Living Whole Organism Artemia by a Natural Fluorimetric Intermediate Siderophore. Issue 22 (9th August 2017) - Mudhulkar, Raju
Abstract: Aeruginic acid (H2 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+ . H2 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 H2 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. Abstract : Sulfur containing intermediate siderophore aeruginic acid showed highly selective and reversible biosensing of Zn 2+ in 100% water at physiological pH even in occurrence of other competing metal ions particularly, Cu 2+ . The ionophore revealed an overall 9‐fold CHEF responses for Zn 2+ with an enhanced excited state life time of 4 ns. This non‐toxic and cell membrane permeable natural ionophore also showed bio‐imaging application by staining Zn 2+ in live brine shrimp Artemia .