Rapid Detection of Cd²⁺ Ions in the Aqueous Medium Using a Highly Sensitive and Selective Turn-On Fluorescent Chemosensor

Abstract

Herein, a novel optical chemosensor, (CM1 = 2, 6-di((E)-benzylidene)-4-methylcyclohexan-1-one), was designed/synthesized and characterized by 1H-NMR and FT-IR spectroscopy. The experimental observations indicated that CM1 is an efficient and selective chemosensor towards Cd2+, even in the presence of other metal ions, such as Mn2+, Cu2+, Co2+, Ce3+, K+, Hg2+,, and Zn2+ in the aqueous medium. The newly synthesized chemosensor, CM1, showed a significant change in the fluorescence emission spectrum upon coordination with Cd2+. The formation of the Cd2+ complex with CM1 was confirmed from the fluorometric response. The 1:2 combination of Cd2+ with CM1 was found optimum for the desired optical properties, which was confirmed through fluorescent titration, Job’s plot, and DFT calculation. Moreover, CM1 showed high sensitivity towards Cd2+ with a very low detection limit (19.25 nM). Additionally, the CM1 was recovered and recycled by the addition of EDTA solution that combines with Cd2+ ion and, hence, frees up the chemosensor.

Keywords

• chemosensor
• curcumin
• heavy metals
• aqueous medium
• high sensitivity