Development of [(2E,6E)-2,6-bis(4-(dimethylamino)benzylidene)cyclohexanone] as fluorescence-on probe for Hg2+ ion detection: Computational aided experimental studies

Abstract

Selective metal ion detection is highly desired in fluorometric analysis. In the current study a curcumin-based fluorescence-on probe/[(2E,6E)-2,6-bis(4-(dimethylamino) benzylidene) cyclohexanone]/probe was designed for the removal of one of the most toxic heavy metal ion i.e. Hg2+. The structure of the probe was confirmed by FTIR and 1H NMR spectroscopic analysis displaying distinctive peaks. The complex formation between probe and Hg2+ ion was also studied by density functional theory to support the experimental results. Chelation enhanced fluorescence was observed upon interaction with Hg2+ ion. Different parameters like pH, effect of mercury ion concentration, contact time, interference study and effect of probe concentration on the fluorescence enhancement were also investigated. A rapid response was detected for Hg2+ ion with limit of detection and quantification as 2.7 nM and 3 nM respectively with association constant of 1 × 1011 M−2. The probe displayed maximum fluorescence intensity at physiological pH. The results showed that the synthesized probe can be employed as an excellent probe for the detection and quantification of Hg2+ ions in aqueous samples with high selectivity and sensitivity due to its higher binding energy and larger charge transferring ability.

Keywords

• Real time analysis
• Fluorescence-on
• Aqueous sample
• Curcumin derivative
• Hg2+ ion