Rapid Detection of Cd 2+ Ions in the Aqueous Medium Using a Highly Sensitive and Selective Turn-On Fluorescent Chemosensor.

Herein, a novel optical chemosensor, ( CM1 = 2, 6-di((E)-benzylidene)-4-methylcyclohexan-1-one), was designed/synthesized and characterized by ¹ H-NMR and FT-IR spectroscopy. The experimental observations indicated that CM1 is an efficient and selective chemosensor towards Cd ²⁺ , even in the presence of other metal ions, such as Mn ²⁺ , Cu ²⁺ , Co ^2+, Ce ³⁺ , K ⁺ , Hg ²⁺ , ^, and Zn ²⁺ in the aqueous medium. The newly synthesized chemosensor, CM1 , showed a significant change in the fluorescence emission spectrum upon coordination with Cd ²⁺ . The formation of the Cd ²⁺ complex with CM1 was confirmed from the fluorometric response. The 1:2 combination of Cd ²⁺ 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 Cd ²⁺ 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 Cd ²⁺ ion and, hence, frees up the chemosensor.