A ‘turn‐off’ fluorescence sensor for selective Hg(II) based on phenothiazine derivative

Abstract

AbstractGiven how crucial it is to preserve a human‐safe and sustainable environment, the rapid discovery of possibly lethal heavy metals such as Hg(II) has drawn much attention in recent years. A novel sensor, known as (E)‐2‐((10‐octyl‐10H‐phenothiazin‐3‐yl)methylene)hydrazine‐1‐carbothioamide (PTZHC), was synthesized as a fluorescence ‘on–off’ sensor for Hg2+ ions. Coordination alters organic molecule electron densities, quenching the fluorescence intensity. PTZHC was described completely with the help of FTIR and 1H‐NMR spectrum studies. The Hg2+ ion was successfully detected using the PTZHC sensor even when there were other metal ions present. The limit of the detection was estimated to be 2.5 × 10−8 M and the Job's plot examination implied that PTZHC was bound to Hg2+ with a simple 1:1 stoichiometry in s CH3CN/H2O (9:1, v/v) suspension. To further cast light on the bridged effect on geometric and optoelectronic characteristics, time‐dependent density functional theory (TD‐DFT) at the B3LYP/6‐31G(d) level and DFT were both examined.