Metal organic framework loaded fluorescent nitrogen-doped carbon nanozyme with light regulating redox ability for detection of ferric ion and glutathione.

The redox state disorder of biological system caused by oxidative stress can lead to a variety of clinical dysfunction and diseases. It is an important challenge to find artificial materials that can efficiently adjust the redox balance to maintain health. In this work, a nitrogen-doped carbon (NCDs) redox nanozyme loaded into metal organic framework (MOF, UiO-66) is designed to form NCDs/UiO-66 nanocomposites. The high specific surface area and porosity of UiO-66 serve as ideal carrier to support multifunctional NCDs. NCDs/UiO-66 nanocomposites are comprehensively investigated for their ability to scavenge or generate reactive oxygen species (ROS) and free radicals. Experimental results demonstrate that NCDs/UiO-66 can remove intrinsic free radicals (OH, O and ABTS), exhibiting superoxide dismutase-like activity and antioxidant capability. Moreover, NCDs/UiO-66 can efficiently produce ROS (OH, O and O) under irradiation showing light induced oxidase-like activity and pro-oxidant capability. This suggests the anti-oxidant and pro-oxidant activities of NCDs/UiO-66 could be regulated easily by light irradiation. Using the fluorescent property and light-activated oxidase-like activity of NCDs/UiO-66, the methods for detection of ferric ion (Fe) and glutathione (GSH) are developed.