Wavelength specific aggregation induced emission in aqueous media permits selective detection of Ag+ and Hg2+ ions.

ABSTRACT

A new 1,8-naphthalimide derivative (probe 1) adopts V-shaped structure, emits fluorescence and displays the Mie effect and aggregation-induced emission (AIE). Selective interactions of thiophilic Ag+ and Hg2+ ions (10 µM) with 1 (10 µM) resulted in AIEs at 499 and 521 nm, respectively. Both Ag+ and Hg2+ induce the formation of 12 complexes with 1, leading to the formation of AIE active aggregates with an average size of 423 and 198 nm, respectively. The formation of crystalline needles with Ag+ and spherical aggregates with Hg2+ results in wavelength specific AIE that permits the naked-eye and fluorometric detection of Ag+ and Hg2+ ions. Probe 1 shows excellent selectivity toward Ag+ and Hg2+ among various metal ions, therefore, 1 is suitable for the selective and quantitative detection of Ag+ and Hg2+ ions. Job plots are used for the determination of the stoichiometry of the complexes formed. It is evident from the fluorescence images of probe 1 in Rhizoctonia oryzae mycelia cells that they can be employed as potential candidates for in-vitro bioimaging.