A Phenazine based colorimetric and fluorescent chemosensor for sequential detection of Ag⁺ and I⁻ in aqueous media

Abstract

Abstract A new colorimetric and fluorescent probe MNTPZ based on 1H ‐imidazo[ 4,5‐b ]phenazine derivative has been designed and synthesized for successive detection of Ag + and I − . The probe MNTPZ shows selective colorimetric response by a change in color from yellow to orange and “turn‐off” fluorometric response upon binding with Ag + in DMSO: Water (pH = 7, 1:1, v / v ) over other cations. The binding mode of probe MNTPZ to Ag + was studied by Job's plot, 1 H NMR studies, FT‐IR spectroscopy and DFT calculations. Moreover, the situ generated probe MNTPZ + Ag + complex acted as an efficient fluorometric “turn‐on” probe for I − via Ag + displacement approach. The detection limit of probe MNTPZ for Ag + and the resultant complex probe MNTPZ + Ag + for I − were determined to be 1.36 μmol/L and 1.03 μmol/L respectively. Notably, the developed probe was successfully used for quantitative determination of I − in real samples with satisfactory results.