Bis-Pyrene-Appended Polyvinyl Chloride: Mechanosynthesis and Nitro-Explosive Detection

The remote detection of nitro compounds typically requires complex analytical procedures and expensive instrumentation, often resulting in prolonged analysis times. Fluorescence-based methods, which exploit the quenching of organic fluorophores in the presence of nitro analytes, offer a more practical and efficient alternative. Particularly promising is the use of excimer emission generated by bis-pyrene species (bis-Pyr), formed either through supramolecular interactions or covalent linkages. Regarding the latter, the integration of covalently linked bis-Pyr sensors onto polymer backbones, such as commercially available polyvinyl chloride (PVC), represents a highly attractive strategy. In this manuscript, we wish to report our recent findings on the mechanosynthesis of bis-pyrene-based PVC-supported chemosensors, and on studies of its fluorescence response towards common nitro-compound/explosive components, such as 2,4-dinitrotoluene (DNT), 2,4,6-trinitrotoluene (TNT), taggant 2,3-dimethyl-2,3-dinitrobutane (DMDNB), pentaerythritol tetranitrate (PETN) and 2,4,6-trinitrophenol (picric acid, PA). For DNT, a selective fluorescence "turn-off" response was observed with a Stern-Volmer quenching constant as high as 1.15 × 10⁴ M^-1.