Detection of explosives and other species

A device for determining a vapor phase peroxide or a vapor phase peroxide precursor, comprising:

• an inlet for intake of a vapor sample suspected of containing the vapor phase peroxide or vapor phase peroxide precursor;
• a sample cell comprising a composition comprising a peroxide-reactive material, a light-emitting material, and a support material, wherein the peroxide-reactive material and the light-emitting material are different, and wherein the composition is in solid form, or, the composition is in solution form and the support material is a liquid having a boiling point of at least 300° C., the sample cell constructed and arranged to receive the vapor sample;
• and
• a detection mechanism in optical communication with the sample cell,
• wherein the peroxide-reactive material is a compound having the formula,
• wherein R′ is a group comprising a sulfonyl and R″ is 2,4,5-trichlorophenyl, 2,3,4,5,6-pentafluorophenyl, 2,4-dinitrophenyl, phenyl, or a substituted derivative of any of these, and the light-emitting material is a compound having the formula,
• wherein R is alkyl, heteroalkyl, aryl, or heteroaryl.