A luminescent sensory material for the detection of the presence of organo-halogen compounds is described. This material is based on a platinum chromophore functionalized with pyridylacetylide ligands, as shown in Formulae I and II below. These complexes exhibit positive luminescence upon exposure to the vapors of organ-halogen compounds like CH₂Cl₂ or CHCl₃ with high selectivity over non-chlorinated common organic vapors. Direct relationships between vapor concentration and luminescence intensity are established using thin films prepared from these complexes. ##STR1##