Novel environmental applications of green tea: sensing and remediation of Ag in aqueous system.

The strong fluorescence of green tea was quenched with Fe because of ligand-to-metal charge transfer and subsequent formation of magnetite (FeO) nanoparticles (heavy metal effect). Ag restored the lost fluorescence by confining iron particles (capped with Cl) with the formation of AgCl. Thus, toxic Ag was sensed in the aqueous system with a linear detection range of 10 M to 10 M and a detection limit of 4.1 × 10 M. The sensing protocol was applied for natural samples to detect Ag. Gallic acid was found to be the pivotal component in the tea extract used to design a sensing platform. The company of the green tea were also varied and obtained comparable results.