Novel Heterostructure of a MXene@NiFe-LDH Nanohybrid with Superior Peroxidase-Like Activity for Sensitive Colorimetric Detection of Glutathione

Developing a simple and efficient method to detect biomarkers is pivotal for early diagnosis of diseases. In this work, a novel 2D/2D heterogeneous structure, consisting of MXene-supported NiFe-based layered double hydroxide nanoflakes (denoted as MXene@NiFe-LDH), is synthesized by an in situ coprecipitation method and, for the first time, is applied as a peroxidase mimic. The results reveal that LDH nanoflakes are vertically aligned on the surface of the MXene nanosheets, forming a 2D/2D heterogeneous hybrid structure. The obtained MXene@NiFe-LDH exhibits superior peroxidase-like activity, which is attributed to the synergetic effect of the MXene and LDH phases, the large ion-accessible surface, and fast electron-transfer pathways in the nanocatalyst. Accordingly, a sensitive colorimetric sensor is proposed to detect glutathione (GSH), displaying a good linearity with GSH concentrations ranging from 0.9 to 30 μM and a low detection limit of 84 nM. The established sensor is further applied in the detection of GSH from human serum and also displays satisfying results.