Abstract:

A new and optically stable fluorescent derivative (OPBMQ) of 1, 4-bis(phenylethynyl)benzene (BPEB) with 8-hydroxyquinoline (8-HQ) as a capturing unit and cholesterol (Chol) as an auxiliary structure was designed and synthesized. Fluorescence studies demonstrated that the fluorescence emission of the compound in the aqueous phase is characterized by two distinct and independent emissions, of which one originates from 8-HQ and the other from BPEB. Importantly, the emission is highly selective and sensitive to the presence of diethyl chlorophosphate (DCP), a simulant of Sarin. The calculated detection limit (DL) is lower than 1 × 10⁻⁹ mol·L⁻¹. Moreover, no significant response was observed when the probe was exposed to simulants of other nerve agents, relevant organophosphorus pesticides, or even their mixtures. More importantly, regardless of whether Milli-Q water, tap water or even sea water was employed as solvent, the presence of the mixture of the interferents studied did not show any significant effect on the detection of DCP. In particular, the sensitive and highly selective detection of DCP was also realized by naked-eye observation, providing a simple and low-cost protocol for the on-site and real-time detection of the chemical. Based on this discovery, a DCP monitoring device was successfully developed.

Key words: 1, 4-Bis(phenylethynyl)benzene, Fluorescence, Sarin, 8-Hydroxyquinoline, Diethyl chlorophosphate