Anthranilic Acid Schiff Base as a Fluorescent Probe for the Detection of Arsenite and Selenite: A Detailed Investigation of Analytical Parameters and Mechanism for Interaction.

The exploration of an anthranilic acid based Schiff base SB as a "Turn-ON" fluorescent probe for the detection of highly toxic selenite (Se) and arsenite (As) species in an aqueous medium is described. The selectivity of SB towards Se and As in the presence of other ions was investigated by some spectrofluorimetric and H NMR spectroscopic experiments. The studies revealed the interaction between SB and As via the deprotonation of phenolic -OH, which enhanced the conjugation in phenolate ion and in turn enhanced the emission response. The SB has analytical prospects for the quantification of As and Se with good sensitivity (LODs; 5.15 ppb for Se and 3.12 ppb for As calculated by S/N = 3σ/K). Furthermore, it can be used to evaluate real and synthetic samples for the presence of Se and As species as well as the fabrication of on-spot recognition devices (in the form of silica gels SB@SiO and silica coated TLC aluminium strips SB@SiO@Al).