Carbon quantum dots and cucurbituril joining hands to achieve luminescence and self-healing performance in a hydrogel

The development of multifunctional hydrogels remains a grand challenge in material science, biomedicine, and other high-tech fields. Herein, we report a new method to use cucurbit[7] (CB[7]) as a cross-linking agent with biocompatible agarose (AG) and polyvinyl alcohol (PVA) forming an interpenetrating network structure by hydrogen bond way, and then doping the low-toxic carbon quantum dots (CQDs) into the hydrogel obtain multifunctional hydrogels (CQDs/PVA/AG/CB[7]). Due to a large number of hydrogen bonds and a few microcrystalline regions, the hydrogel exhibits excellent mechanical properties, and the CQDs also improve the elastic modulus of the hydrogels by 78%. CB[7] as the mobile phase makes the hydrogel a self-healing ability. The CQDs doped into the hydrogel not only solve their aggregation but also make the hydrogel be stronger fluorescence than that of CQDs. This work provides a well-guided approach for rationally designing and developing other multifunctional hydrogels. Luminescent and self-healing hydrogels with low toxicity and excellent mechanical properties are significant for drug delivery, biological imaging, and biosensor. Carbon quantum dots and cucurbituril joining hands to construct multifunctional luminescence hydrogels are reported to achieve excellent biocompatibility, outstanding self-healing, and mechanical properties. This work offers a new way to design biomedical engineering materials.