A novel luminescent Ni(II) coordination compound for highly selective detection of acetylacetone, MnO4-, tetracycline and Ag+ in aqueous systems

A new Ni(II) compound [Ni(bim)(2)(H2O)(4)] (1,5-nds)(H2O)(0.5) 1 (bim = benzimidazole, 1,5-nds-Na = disodium 1,5-naphthalenedisulfonate) was readily synthesized at room temperature. Although compound 1 is only a mononuclear compound, it is extended into a 2D supermolecule layer by hydrogen bonding interactions. Hirshfeld surfaces and fingerprint maps of compound 1 crystal packing were calculated to gather information on non-covalent interactions. Photoluminescence experiments showed that 1 not only possessed good solid-state fluorescence performance but also favorable fluorescence characteristics and stability in aqueous solutions, which can be exposed to acidic and alkaline environmental conditions (pH = 1-14) for a long time. Remarkably, compound 1 displayed outstanding anti-interference properties, high sensitivity, high quenching rate, and low limit of detection (LOD) against acetylacetone (acac), MnO4-, and tetracycline (TET) in water media via the Turn-Off effect (LOD:7.03 mu M for acac, 2.92 mu M for MnO4- and 0.65 mu M for TET). Especially, compound 1 can also be used as a rare ratiometric fluorescent probe for the detection of Ag (+) down to the nM level. The exceptional multi-responsive performance suggested that compound 1 could be a potential multifunctional sensor. Furthermore, possible mechanisms were systematically investigated.

Automated summary

A new Ni(II) compound with good solid-state fluorescence performance and stability was synthesized, and it showed outstanding detection properties for various substances in aqueous solutions. This compound has the potential to be a multifunctional sensor.