Fabrication of 1,8-naphthalimide modified cellulose derivative composite fluorescent hydrogel probes and their application in the detection of Cr(VI).

The design and development of a rapid and quantitative method for the detection of heavy metal ions is of great importance for environmental protection. We have prepared a 1,8-Naphthalimide modified cellulose composite fluorescent hydrogel (CENAEA/PAA) with a stereo double network structure. Characterized by excellent hydrogel functional structure and fluorescence detection performance, it can efficiently and selectively identify and detect Cr(VI) with linear quenching in the range of 0-400 µmol/L and detection limit of 0.58 µmol/L for Cr(VI). The results show that the CENAEA/PAA can effectively adsorb Cr(VI) with a maximum adsorption capacity of 189.04 mg/g. Finally, the morphological characteristics, chemical structure, fluorescence properties and adsorption behavior of CENAEA/PAA were analyzed and fitted well with the pseudo-second-order model and Freundlich model. Thus, the present work provides a green and sustainable approach for the synthesis of a functional material that can be used for the detection and adsorption of heavy metal ions.