Construction of a multifunctional polysaccharide-based aerogel for highly efficient fluorescence detection and removal of formaldehyde

Formaldehyde as an indoor air pollutant poses a serious threat to human health owing to its high toxicity, wide distribution, and long release time. Therefore, the development of methods for the sensitive detection and removal of indoor formaldehyde is crucial. A robust aerogel based on cotton cellulose (CC) and chitosan (CH) with high sensitivity toward formaldehyde was constructed for visual formaldehyde detection and removal. Owing to the presence of a highly sensitive ratiometric fluorescent probe RP, CHCC-RP exhibited up to 600-fold fluorescence enhancement (F540/F450) in a formaldehyde-containing atmosphere. The detection limit was approximately 0.5 × 10−7 M, and the aerogel exhibited a rapid fluorescence response and high selectivity toward formaldehyde. Moreover, the composition of CHCC-RP was optimized, and the physical and formaldehyde-response properties were examined via texture analysis, X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy (XPS). CHCC-RP exhibited excellent formaldehyde adsorption capacity, and over 70% of the NH2 group in the aerogel was consumed by formaldehyde, as indicated by the XPS and Fourier-transform infrared spectra. Additionally, CHCC-RP and RP could successfully detect formaldehyde in live zebrafish with remarkable fluorescence changes.