A cellulose-based fluorescence aerogel for Hg2+ monitoring and its applications in food samples: From sensitive detection to efficient adsorption.

Mercury ion (Hg2+) is a heavy metal ion that poses significant threats to food safety and human health. Herein, a cellulose acetate-based fluorescent probe PPNA-CA for the precise recognition of Hg2+ in food samples and efficient adsorption of Hg2+ in aqueous solution was rationally synthesized. PPNA-CA exhibited low emission intensity in solution, while the emission intensity was rapidly increased in the existence of Hg2+ accompanied with variation of the fluorescence color from weak yellow to bright yellow. This probe showed good sensitivity (97 nM), ultrafast response (20 s) and excellent selectivity towards Hg2+. The sensing mechanism was verified by Job's plot, FT-IR and 1H NMR analyses. PPNA-CA was successfully used for the determination of Hg2+ in drinking water, vegetable and seafood samples. More importantly, PPNA-CA-based aerogel not only accomplished detection of Hg2+ in solution but also facilitated the efficient removal, exhibiting excellent adsorption selectivity and adsorption capacity towards Hg2+ in mixed solution, and can serve as a dual-functional material for sensing and adsorption.