Visual colorimetric detection of ammonia under gaseous and aqueous state: Approach on cesium lead bromide perovskite-loaded porous electrospun nanofibers

In this work, we fabricate porous cesium lead bromide nanofibers (CsPbBr₃ NFs) via electrospinning and employ them in a sensor to effectively detect both gaseous and aqueous ammonia. The CsPbBr₃ NFs are produced by first mixing cesium lead bromide nanocrystals (CsPbBr₃ NCs) with polystyrene (PS), followed by solidifying the mixture into NFs using electrospinning. Porous NFs are modified using the volatile solvent toluene, which is volatilized during the electrospinning process. The applicability of the proposed CsPbBr₃ NFs for use under various environmental conditions is verified by analyzing their stability in response to changes in temperature, moisture level and pH, which are critical drawbacks of CsPbBr₃ NCs. Gaseous ammonia (9 mg L⁻¹) in an N₂ carrier is subsequently detected using the photoluminescence (PL) properties of the CsPbBr₃ NFs. In addition, an ammonia concentration of 100.0 mg L⁻¹ in an aqueous solution can be detected using the PL intensity. Therefore, we believe that the proposed CsPbBr₃ NFs show significant promise for use in detection sensors to assess the extent of food decay, allowing customers to purchase fresh agricultural products more safely.