The carbazole-based conjugated dendrimer H2-BCz with tert-butyl surface groups shows selective gelation behavior in a good solvent and anti-solvent mixture. The sol-gel conversion of H2-BCz can be observed on heating and cooling. The H2-BCz xerogel films show three-dimensional porous networks with the nanofibers (layered structures with a period of 1.38 nm) entangling and intersecting with each other. The π-π interactions between the aryl units may be the driving force for the formation of one-dimensional H2-BCz fibers during the gelation process. Due to the electron-donating property of the H2-BCz molecule and the porosity of the fibrous film, the xerogel films can be used as efficient fluorescence quenching based chemsensors for the detection of nitroaromatic explosives, such as 2,4,6-trinitrotoluene (TNT) and 2,4-dinitrotoluene (DNT). The quenching efficiency was as high as 77% and 91 % when exposed to the vapor of TNT and DNT, respectively.
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