Trace Level Recognition of Zn 2+ and Cd 2+ by Biocompatible Chemosensor inside Androecium, Diagnosis of Pick's Disease from Urine and Biomimetic β-Cell Exocytosis.

Two chemosensors with varying substitution have been synthesized for selective detection of d 10 metal ion analyte Zn 2+ and Cd 2+ by fluorometric method from aqueous medium at very low limit of detection. Density functional theory (DFT)-based Loewdin spin population analysis reveals that methoxy-substituted chemosensor is much stronger donor than bromo-substituted chemosensor. Eventually, bromo and methoxy substituted chemosensors are moderate and strong donor, respectively, toward selective detection of Cd 2+ and Zn 2+ by luminescence induced phenomenon (blue for Cd 2+ and cyan for Zn 2+ ). The mechanism of sensing could be explained by PET-CHEF-C = N isomerization-ILCT pathway. 1 H NMR, ESI-MS and FT-IR has been carried out in order to explore the selective ion sensing mechanism. Intracellular detection of Zn 2+ and Cd 2+ has been carried out inside androecium (filament and pollens) of Tecoma Stans. Extracellular detection of Zn 2+ for yeast cells represents the bio mimetic model experiments toward β-cells exocytosis as a marker of diabetes mellitus . The unprecedented and novel feature of the present biocompatible chemosensor is its application as biosensor to detect in vivo Zn 2+ from human urine specimen which could be a next generation diagnostic tool for Pick's disease .