A simple urea-based multianalyte and multichannel chemosensor for the selective detection of F−, Hg2+ and Cu2+ in solution and cells and the extraction of Hg2+ and Cu2+ from real water sources: a logic gate mimic ensemble

Abstract

Herein, a hydrazine-based chromogenic, fluorogenic and electrochemical chemosensor BCC [1,5-bis(4-cyanophenyl) carbonohydrazide] was premeditated and synthesized through a simple one-step synthetic procedure for the selective detection of toxic anions, such as F⁻, in a DMSO–ACN medium and cations, such as Hg²⁺ and Cu²⁺, in a MeOH–water medium. The detection limit for F⁻ was reckoned to be 0.5 ppm, and for Hg²⁺ and Cu²⁺, it was 0.8 ppm and 50 nM, respectively. The chemosensor exhibited a distinct change in colour from colourless to dark blue in the presence of F⁻, and upon the addition of Hg²⁺ and Cu²⁺, the BCC turned from colourless to light blue and purple accordingly. Moreover, turn-on fluorescence response transpired by the attenuation of PET signified the selective sensing of analytes with a zero-order rate constant. Sophisticated analytical experiments, such as ESI-MS, UV-Vis, photoluminescence, cyclic voltammetry, FTIR, and ¹H-NMR, along with the theoretical calculations corroborated the probable sensing pathways. The reversible colorimetric response of BCC towards F⁻ and H⁺ can be advantageous in the design of electronic circuits derived from Boolean algebra. The complexation ability of the sensor with toxic Hg²⁺- and Cu²⁺-like ions made it an efficient material to remove these metal ions from real water sources polluted with these toxic elemental ions. Furthermore, the in vitro studies were accomplished using the Bauhinia acuminate pollen cell to check the cell penetrability of the sensor molecule.