1D supramolecular assembly-induced emission and colorimetry toward precise onsite mercury(II) detection

• Designed a new platinum(II) terpyridyl complex/chloride probe. • 1D supramolecular assembly-induced for detection of mercury(II). • Detection of mercury(II) with dual-visual signal, with turn-on red luminescence. • Capable of detecting lower concentrations of mercury(II) in complex environments. Manipulation of the one-dimensional (1D) supramolecular assembly of platinum(II) terpyridyl complex is promising for achieving precise onsite mercury(II) detection in complex environments, but still challenging. Herein, by systematic molecular design of platinum(II) terpyridyl complex, chloride-mediated 1D supramolecular assembly has been successfully achieved, exhibiting not only improved recognition ability but also dual-visual signal, with turn-on red luminescence and high-contrast color change from pale-yellow to orange-red. The probe also shows excellent selectivity and anti-interference properties, fast response rate (< 1 s) and low detection limit, stretching to 20.6 fg when incorporated in a hydrogel matrix. Structure insight for the dual-visual response shows that this high detection performance derives from the ancillary ligand of -NCS, which endows the increase of ion-association ability between platinum(II) terpyridyl complex and [HgCl 4 ] 2− , leading that 1D packing mode with strengthened Pt-Pt interactions. In all, this work highlights a new strategy of 1D supramolecular assembly construction for high performance detection of heavy metal ions.