Synthesis and characterization of a xanthene-based molecular probe to detect triphosgene in solution and vapor phases

Abstract

The ability of a detection approach to direct a visible and easy-to-monitor characteristic is an important aspect of molecular-level detection. From this viewpoint, we developed the molecular probe Xanth-Py, which allows us to visually detect triphosgene (TPG) by modulating the probe's photophysical characteristics. Since Xanth-Py exhibits a strong fluorescence, its interaction with TPG causes the non-radiative decay of the probe. As TPG concentrations increase, the fluorescence intensity decreases linearly, leading to a nanomolar level detection limit. The interaction of Xanth-Py with TPG accompanied a color change from pink to blue, enabling a visible detection protocol. Probe-coated paper strips have been used as an inexpensive detection tool for vapor-phase TPG detection, revealing the potential of the Xanth-Py. Further, triphosgene has been detected using a smartphone-assisted RGB analysis tool in conjunction with a portable UV-light source device.