Highly selective "turn-on" fluorescence determination of mercury ion in food and environmental samples through novel anthracene and pyrene appended Schiff bases

Novel pyrene- and anthracene-based Schiff base derivatives (A1 and P1) were designed and prepared for selective "turn-on" fluorescence determination of Hg2+ ions in food and environmental samples. Structural characterization of novel compounds was performed by standard spectroscopic methods and photophysical properties were exanimated by UV-vis, steady-state fluorescence, time-resolved fluorescence, 3D-fluorescence and excitation-emission matrix (EEM) analysis. Investigation of binding and interaction mechanism clearly indicated that A1 and P1 can sensitively and selectively detect Hg2+ ions in real samples via inhibition of PET processes after 1:1 complex formation. In order to perform the determination of Hg2+ ions in food and environmental samples, experimental conditions such as pH, buffer, sensor concentration and measurement time were optimized. The detection limits of presented methods were determined as 12.22 nM (2.45 mu g L-1) and 8.32 nM (1.67 mu g L-1) in the linear range of 0.005 mu M-45 mu M and 0.008 mu M-38 mu M for A1 and P1, respectively. After validation with ICP-MS and spike/recovery test, A1 and P1 were successfully used for fluorescence analysis of Hg2+ ions in food and environmental samples. In addition, the paper-based test kit was prepared with pyrene appended Schiff base (P1) which, could be applied successfully for monitoring Hg2+ ions.