Sensors dinitrobenzenes

An important demonstrated application of this artificial nose system is the high-speed detection of low levels of explosives and explosive-like vapors. Several sensors, based on Nile Red attached to silica microspheres, show high sensitivity to nitroaromatic compounds (NAC) within a mixture12. Different fluorescence response profiles were observed for several NAC s, such as 1,3,5-trinitrotoluene (TNT) and 1,3-dinitrobenzene (DNB), despite their similar structures. These responses were monitored at low concentrations of the NAC vapors (ca. 5 ppb) and at short vapor exposure... 

Binding of molecules of TNT or any one of a suite of related nitroaromatic compounds commonly associated with the presence of TNT (for example, 2,4-dinitrotoluene), or photochemical or microbial degradation products of TNT (1,3-dinitrobenzene or amino-dinitrotoluenes) results in a dramatic reduction in the emission intensity of films of AFP. The reduction in emission intensity is proportional to the mass of quencher adsorbed by the films and is measured by the sensor system. A schematic of an early Fido prototype is shown in Figure 4. 

Tetrakis(4-pyridyl)porphyrin was covalently linked to GO and electrochemical reduction of explosive nitroaromatic compounds was obtained by the hybrid, thus performing detection of ultra-trace explosives [121]. Comparing the sensitivity and detection limit of various electrochemical sensors toward TNT detection, the resulting porphyrin/graphene-modifled GC electrode was of superior quality, allowing detection of 0.5 ppb. Detection limit for other nitroarenes were 1 (2,4-dinitrotoluene), 1 (1,3,5-trinittobenzene) and 2 (1,3-dinitrobenzene) ppb, respectively. 

Lu X, Shan D, Yang J, Huang B, Zhou X. Determination of m-dinitrobenzene based on novel type of sensor using thiol-porphyrin mixed monolayer-tethered polyaniline with intercalating fullerenols. Talanta 2013 115 457-61. 

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