Phosgene is a widely used yet highly hazardous compound that poses serious risks to human health and public safety due to its potential for misuse and accidental release. Therefore, developing an accurate and highly sensitive detection method is of critical importance. In this work, we have synthesized a sulfo-cyanine-based dye (CyNH) for the selective rapid detection (<1 min) of phosgene by Near-IR turn-on colorimetric and fluorescence responses. Notably, CyNH exhibited a 3-fold fluorescence enhancement at 756 nm accompanied by a distinct color change from light blue to dark blue by the appearance of strong absorption signal at 600 nm, with a detection limit of 1.17 μM. To enable on-site detection, a 3D-printed sensor of the CyNH-coated 3D-printed substrate was developed, which shows visible color changes upon exposure to phosgene. Furthermore, integration of this sensor with a smartphone camera and its processing capabilities allows for real-time quantification of phosgene concentrations by eliminating the need for costly analytical instruments. To the best of our knowledge, the development of an NIR probe enabling dual colorimetric and fluorescent NIR detection of phosgene using a 3D-printed sensor is scarcely reported. This innovative 3D-printed, smartphone-assisted sensing platform offers a practical and sustainable approach for future phosgene detection applications in various fields.
Shinziya et al. (2026) studied this question.