A simple Cu(II)-dppy complex for selective detection of hazardous sulfide anion in water and its application in DNA and BSA binding

•Synthesis and characterization of Cu(II) complex ([CuL2]Cl2) of dppy ligand L•Utilization of water soluble [CuL2]Cl2 receptor for sulfide detection in water•Noteworthy interactions of [CuL2]Cl2 receptor with CT-DNA and BSA The traditional hazardous sulfide species (S2–, HS–, and H2S) are widely dispersed throughout the environment and have widespread applications in various industrial processes. Despite numerous applications, excessive exposure to sulfide species can lead to several chronic diseases. In light of the importance of sulfide detection in water, we have reported a novel water-soluble 1:2 copper complex ([CuL2]Cl2) of 2,2′-(4-(3,4-dimethoxyphenyl)pyridine-2,6-diyl)dipyrazine ligand L. The [CuL2]Cl2 receptor has been utilized for the sulfide detection in the vicinity of other anions of higher concentration (ten equivalents of F−, I−, Br−, Cl−, H2PO4−, NO3− HCO3−, OH−, CH3CO2−, SO42−, CO32−, P2O74- (PPi), SO32−, HPO42−, S2O32− (10 mM)) in water at physiological pH 7.4 (10 mM HEPES buffer) with the help of absorption spectral studies and colorimetric study. The detection limit of sulfide is calculated to be 1.13 µM. DFT calculations suggested that the most exergonic free energy (-31.99 kcal/mol) is associated with sulfide, leading to the displacement of Cu(II) ion from the [CuL2]Cl2 receptor, which well supported the experimental absorption spectral data. In addition, [CuL2]Cl2 receptor also demonstrated noteworthy interactions with Calf-Thymus DNA (CT-DNA) and bovine serum albumin (BSA). [Display omitted]