A novel chromophore reaction-based pyrrolopyrrole aza-BODIPY fluorescent probe for H2S detection and its application in food spoilage

In this work, we developed an aggregation-induced emission enhancement (AIEE) active and NIR emissive pyrrolopyrrole aza-BODIPY (PPAB) polymer (P1) for H2S detection for the first time. P1 showed obvious colorimetric change from green to yellow-green and ratiometric fluorescence “turn on” phenomenon with 167 nm blue-shift (from dark red to bright green). The sensing mechanism revealed a novel chromophore reaction between imine in PPAB core and H2S was involved, leading to less conjugated product. It exhibited distinct advantages of good selectivity, high sensitivity, and low detection limit of 0.66 μM. The potential applicability of P1 for H2S detection in the real samples (tap water, lake water and milk) was demonstrated. In addition, the solid sensor prepared by loading P1 on the PMMA film was successfully realized the visual detection of gaseous H2S gas produced from egg spoilage. Therefore, this work provides a promising approach based on novel sensing mechanism for monitoring H2S in complicated biological systems and practical food samples.