Cs3Cu2I5 perovskite nanocrystals embedded in room temperature curable deep eutectic solvents for sensing NH3 gas

Cu-based perovskite nanocrystals (NCs) have received great interest as alternatives to lead-based perovskite NCs due to their unique advantages of resource abundance and being environmentally friendly. However, the issue of their inherent low luminous efficiency has limited the application of fluorescence sensing fields. In this work, a highly sensitive fluorescence sensor based on Cu-based perovskite NCs has been constructed by embedding Cs3Cu2I5 NCs in room temperature curable deep eutectic solvents (Cs3Cu2I5-DES) for the detection of NH3 gas in the atmosphere. In this strategy, Lauric acid-based DES with room temperature curable property were successfully synthesized and used as the supporting materials of Cs3Cu2I5-DES sensing film. When NH3 gas exists, NH3 can be adsorbed and enriched on the surface of Cs3Cu2I5-DES film, and react with the carboxyl group on the DES, which leads to a significant decrease in the fluorescence intensity of Cs3Cu2I5-DES film. Under optimized experimental conditions, the as-prepared sensing film demonstrated a good linear relationship between the decreased intensity of the fluorescence and the NH3 concentration, and a low limit-of-detection (LOD) of 0.0642 ppm for NH3. Furthermore, the sensor also exhibited excellent selectivity and good stability.