Imidazolylmethylpyrene sensor for dual optical detection of explosive chemical: 2,4,6-Trinitrophenol

Abstract

© 2017 Elsevier B.V. Fluorescence and colorimetric sensor with simplistic synthesis method based on 1-imidazolylmethylpyrene (IMPY) was found to be a specific recognition for an explosive chemical: 2,4,6-trinitrophenol or picric acid (PA). The sensor did not only provide highly sensitive OFF–ON fluorescence enhancement toward PA in acetonitrile, but also offered ON–OFF fluorescence quenching upon PA binding in toluene solution. In addition, the sensor IMPY provided high selectivity to 2,4,6-trinitrophenol and was shown to discriminate various phenolic compounds such as p-iodophenol, p-bromophenol, m-hydroxybenzaldehyde, o-nitrophenol, m-nitrophenol, p-nitrophenol and 2,4-dinitrophenol. Upon binding to PA, the fluorogenic change of the sensor were observed and accompanied by the noticeable chromogenic change from colorless to yellow, therefore the sensor could also serve as a “naked-eye” indicator. Finally, two different types of crystal structures of IMPY·PA complexes were successfully recrystallized and characterized, which confirmed highly interactive affinity of the host-guest molecules.