Spectrofluorometric method for sensing cobalt (II) ion in environmental sample using Ru(dcpy)2(SCN)2 receptor

• The fluorescent receptor Ru(dcpy) 2 (SCN) 2 was used for sensiting Co (II). • The detection and quantification limits were obtained 04.95 and 14.97 µM, respectively. • The selectivity of receptor towards Co 2+ was achieved. • The Co(II) linked to C=O and OH of the receptor. Fluorometric assay was employed for the detection of Co 2+ ions based on their rapid reaction with Ru(dcpy) 2 (SCN) 2 as the receptor in acetate buffer solution (pH = 3.50). A high fluorescence intensity of the receptor was observed in an acetate buffer at pH = 3.50. The calibration curve was plotted between the fluorescence emission of the receptor at λ = 633 nm versus the Co 2+ concentration. The detection (LOD) and quantitation (LOQ) limits were determined to be 04.95 and 14.97 µM (R 2 = 0.99), respectively. The selectivity of suggested method was obtained for Co 2+ outweighs that of transition metal cations with 2 % significant interference with Ni 2+ . The recovery of the Co(II) ions founded 99.6 %. The experiments and electronic surface mapping(ESP) were illustrated the chemical reactivity of receptor and Co(II). The Co(II) was attached to C O rather than −NCS group of the receptor. The proposed method was successes in the determination of Co(II) in the environmental water sample.