Discrimination of nitroaromatics and explosives mimics by a fluorescent Zn(salicylaldimine) sensor array

Detecting and identifying components of plastic explosive devices is a challenge to current optical sensing methods. We report a fluorescent Zn(salicylaldimine) sensor array that accurately discriminated nitroaromatics, which are mimics of plastic explosives. Nitroaromatics quench the fluorescence of Zn(salicylaldimine), with differential quenching for the various fluorophore/quencher partners. The response pattern of the Zn(salicylaldimine) array created unique fingerprints for each of the nine nitroaromatic analytes tested, including unique responses for dinitrotoluene and dinitrobenzene. Linear discriminant analysis showed that the discrimination is largely due to a combination of two physical properties of the nitroaromatics: redox potential and log P. The array was able to discriminate unknown nitroaromatic samples in solution.