An efficient copper(II) salamo-based complex fluorescence chemosensor for detecting sulfide ions: Structure exploration and practical application

•A salamo-type probe l-Cu2+containing 1,8-naphthalimide fluorophore was synthesized firstly.•The probe l-Cu2+can specifically detect S2- further validated through ESP analysis.•Good results in test strip, actual water samples and antibacterial activity were achieved. A novel salamo-based fluorescent chemical sensor l-Cu2+ was designed and prepared via the reaction of H2L and Cu(OAc)2·H2O. The whole research has found that Cu(II) atom in the complex crystal are located in the N2O2 cavity of H2L, forming a four-coordination system. Hirshfeld surface analysis confirmed the presence of hydrogen bonding and π···π stacking interactions. As a probe molecule, l-Cu2+can selectively and sensitively detect S2- without interference from other ions, and can be effectively used within the biological pH range. In addition, DFT theoretical calculations and molecular electrostatic potential analysis (ESP) were used to investigate the electron cloud density and positive and negative electrostatic potentials inside the probe, as well as the mechanism for identifying sulfur ions. Finally, the probe l-Cu2+has shown good practical application effects and can recognize S2− in three different water samples. It can also be used as a qualitative detection strip. l-Cu2+complex possesses excellent application prospect in bacteriostasis. [Display omitted]