Effective strategies
for the detection and identification
of explosives
are highly desirable. Herein, we illustrate the efficient optoelectronic
detection of nitroaromatic and peroxide-based explosives using amine-
and phosphine-substituted diketopyrrolopyrroles. Selective quenching
and an unprecedented enhancement of thin-film emission in the presence
of nitroaromatic vapors are demonstratedviathe
judicious choice of amine substituents. The modulation of fluorescence
emission in each case is shown to be dominated by electronic and thermodynamic
effects, the vapor pressure of explosives, and the thin-film morphology.
For peroxide detection, we describe an approach exploiting redox-mediated
functional group transformation. The rapid oxidation of triphenylphosphine
to phosphine oxide with hydrogen peroxide affords a significant increase
in fluorescence emission, facilitating the sensitive turn-on detection
of an important class of explosives at ppb concentrations.