Ti3C2Tx MXene derived TiO2/C-QDs as an oxidase mimic for efficient diagnosis of glutathione in human serum
Nanozyme based colorimetry was suggested to be rapid method for biomarker (e.g. glutathione) detection, but was lack of efficient and low-toxicity nanozyme till now. Herein, quantum dots of TiO2 loaded on carbon (TiO2/C-QDs) oxidase-like nanozyme were prepared from hydrothermal treatment of the tiny and few-layered Ti3C2Tx MXene nanosheets, which possessed abundant thermodynamic metastable Ti atoms on MXene margin as raw materials for preparation of the TiO2/C-QDs. The oxygen vacancy in TiO2 on the surface of the CQDs can facilitate the O2 adsorption in the solution and generate the reactive oxygen species (ROS), thereby could quickly oxidize 3,3’,5,5’-tetramethylbenzidine (TMB) to its oxidized form (TMBox) in the absence of H2O2. After adding glutathione (GSH), TMBox was able to be restored to TMB, which resulted in the corresponding decrease in UV-vis absorbance value at 652 nm. Furthermore, this assay possessed good selectivity, excellent specificity and high sensitivity (Lowest detection limit: 0.2 μM), which made it possible to efficiently detect GSH in the complex biological samples such as human serum.