Three-dimensional cellulose acetate nanofiber aerogels: A novel platform for ratiometric fluorescence sensing of volatile amines in aquatic products

This study presents the development of cellulose acetate nanofiber aerogels (CA NFAs) as a novel solid-phase carrier for ratiometric fluorescence sensors, designed for detecting volatile amines, which is critical for monitoring the freshness of aquatic products. The sensors were functionalized with fluorescein isothiocyanate (FITC) as an indicator and protoporphyrin IX (PPIX) as an internal reference, which were covalently attached to the cellulose backbone. The FITC/PPIX-CA NFAs were fabricated using electrospinning and freeze-drying techniques, resulting in a 3D porous structure that significantly enhanced the mass transfer of target gas molecules and their interaction with probe molecules. The obtained sensors show high sensitivity to trimethylamine (TMA) with detection and quantification limits of 2.38 ppb and 7.92 ppb, respectively, and the ability to measure fluorescence intensity changes within just 10 s of exposure. Comparative analysis revealed that the 3D structured FITC/PPIX-CA NFAs outperformed traditional 2D thin film sensors in sensing volatile organic compounds due to better interaction between gas molecules and probe molecules. This study underscores the potential of CA NFAs as an advanced solid-phase carrier for constructing ratiometric fluorescence sensors, offering a practical, non-destructive method for monitoring the freshness of aquatic products. [Display omitted]