Sensors and sensitivity : A highly luminescent microporous metal–organic framework, [Zn2(bpdc)2(bpee)] (bpdc=4,4′‐biphenyldicarboxylate; bpee=1,2‐bipyridylethene), is capable of very fast and reversible detection of the vapors of the nitroaromatic explosive 2,4‐dinitrotoluene and the plastic explosive taggant 2,3‐dimethyl‐2,3‐dinitrobutane, through redox fluorescence quenching with unprecedented sensitivity (see spectra).