Visual Hg(II) sensing in aqueous solution via a new 2,5-Bis(4-pyridyl)thiazolo[5,4-d]thiazole-based fluorescence coordination polymer

•A new fluorescence coordination polymer based on 2,5-bis(4-pyridyl)thiazolo[5,4-d]thiazole was prepared for Hg(II) sensing.•The coordination polymer exhibited fluorescence quenching and bathochromic shift toward Hg(II)0.3. The detection can be performed in neutral aqueous solution.•Interactions between Hg(II) ions and Py2TTz ligands in the coordination polymer were responsible for the fluorescence emission change.•Fast & highly selective detection of Hg(II) in real water samples and solid test paper were also achieved.