Isatin Hydrazone as a Colorimetric Chemosensor for the Selective Detection of Mercury (Hg۲+)

A highly sensitive and selective colorimetric chemosensor for Hg۲+ ions was prepared by the use of the well-known isatin chromophore, hydrazine hydrate, and ۴-hydroxybenzaldehyde. In EtOH solution, the synthesized adsorbent showed a visual color change from melon yellow to dark orange with a remarkably large red shift (۷۵ nm) in the presence of Hg۲+. This color change is due to the formation of a ۱:۱ metal-ligand complex. In complex, nitrogen atom of hydrazone group and oxygen atom of lactam group were coordinated to Hg۲+, while the hydroxyl group on the phenyl ring plays an important role in color change. The detection limit of the synthesized colorimetric chemosensor for mercury ions was ۱.۸±۰.۲ μM. The H۱ was synthesized as a colorimetric chemosensor based on isatin hydrazone and ۴-hydroxy benzaldehyde for monitoring mercury ions. The H۱ probe showed a high sensitivity to Hg۲+ ions, that interact from its nitrogen and oxygen atoms against mercury cations, with a detection limit of ۱.۸±۰.۲ μM. In future research, we intend to modify the structure of isatin hydrazone so that it acts as a logic gate to detect two or more agents, showing different color changes.

کلیدواژه ها:

Colorimetry ، Chemosensor ، Isatin ، Selective mercury detection