Rapid nitroaromatic compounds sensing based on oligopyrene

Conjugated oligopyrene with high fluorescence quantum yield was synthesized by a simple one-step electropolymerization of pyrene in a mixed electrolyte of boron trifluoride diethyl etherate and diethyl ether, and thin film fluorescent sensors based on this material were fabricated through a spin-coating technique. These oligopyrene sensors showed rapid fluorescence quenching upon exposure in nitroaromatic compound vapors including trinitrotoluene, dinitrotoluene and nitrobenzene. In combination with theoretical investigation, it was concluded that the high performance of these sensors was due to the high fluorescence quantum yield, “molecular wire” effect, the large free energy change for electron transfer from the excited oligopyrene to the analytes, and the twist chain structures in the sensing films.