ABSTRACT A novel fluorescent probe, sodium alginate dialdehyde‐lysine Schiff base (SAGDLS), has been synthesized for selective and efficient detection of Ni 2 + ions in aqueous medium. SAGDLS is prepared via periodate oxidation of sodium alginate to sodium alginate dialdehyde (SAGD), followed by condensation with L‐lysine, an α‐amino acid. SAGD and SAGDLS are characterized through a range of analytical techniques, comprising 1 H NMR, 1 3 C NMR, FTIR, TGA, and FESEM with EDAX, to confirm their structural properties. SAGDLS exhibits a quantum yield of 0.565 and binds Ni 2 + ions in a 2:1 ratio with an apparent binding constant of 4.81 × 10 7 M − 1 . The probe demonstrates high sensitivity, with a limit of detection (LOD) of 1.25 nM and limit of quantitation (LOQ) of 4.18 nM. Real sample analysis shows excellent recovery percentages (99‐105.55%) and low relative standard deviation (RSD) values (2.35‐3.59%), highlighting SAGDLS's potential as a reliable Ni 2 + ion sensor.
Saren et al. (2026) studied this question.