Poly(vinyl alcohol)–Carbon Nanodots Fluorescent Hydrogel with Superior Mechanical Properties and Sensitive to Detection of Iron(III) Ions

A high‐strength fluorescent hydrogel is prepared by physical cross‐linking of carbon nanodots (CNDs) with poly(vinyl alcohol) (PVA). The stretching and compression of the PVA hydrogel are improved with CNDs by 176% and 64%, respectively. It still has excellent self‐healing behaviors without adding other healing agents. In addition, the search for rapid detection of heavy metals is still a huge challenge. The resulting hydrogel exhibits fluorescence quenching in the presence of Fe³⁺ by the fluorescence characteristics of CNDs, which has high selectivity and sensitivity. The PVA‐CNDs fluorescent hydrogel can be used as a solid detection platform for Fe³⁺, where the detection limit is found to be 10 µm for Fe³⁺ by fluorescence studies.