Development of Binary Coassemblies for Sensitively and Selectively Detecting Gaseous Sarin.

Abstract

The low sensitivity and poor selectivity of fluorescence sensors for real gaseous sarin detection greatly hinder their real-world applications. In this work, we report the development of a novel fluorophore with an active N-H vibration in the benzimidazole group for the sensitive detection of gaseous sarin. We demonstrate that the interactions between the nucleophilic fluorine atom in sarin and the electrophilic hydrogen atom in the benzimidazole group of the fluorophore can restrict the N-H vibration to yield sensitive fluorescence-enhancing responses. On the basis of this mechanism, the experimental and theoretical limits of detection for gaseous sarin can reach as low as 50 and 4.8 ppb, respectively. We further coassemble this fluorophore with another two D-A fluorophores containing different acceptor groups and use the resulting coassemblies as sensor array members to obtain access to differential combined responses to gaseous sarin compared with various interferents, including diethylchlorophosphate and acids. This two-member sensor array proves to be capable of detecting trace sarin in complex environments, demonstrating its potential applications in the real world.