Hierarchical microtubes constructed using Fe-doped MoS 2 nanosheets for biosensing applications.

The structural design of multiple functional components could enhance the synergistic catalytic performance of MoS 2 -based composites in enzyme-like catalysis. Herein, one-dimensional (1D) Fe-MoS 2 microtubes were designed to prepare tubular Fe-doped MoS 2 composites with MoO 3 microrods as self-sacrificing precursors. Remarkably, the results indicated that the generated ammonia released from the sulfidation process led to the dissolution of MoO 3 cores and the generation of a tubular structure. The Fe-MoS 2 composites integrated the synergistic effects of Fe-doped MoS 2 nanosheets (NSs) and the 1D tubular structure. Thus, a higher catalytic activity was observed in peroxidase-like catalysis than in other components, such as MoO 3 @FeOOH, FeOOH and MoS 2 NSs. The peroxidase-like mechanism originated from the generation of the ˙OH radical. The Fe-MoS 2 microtube-based colorimetric assay was used to detect H 2 O 2 with a detection limit (LOD) of 0.51 μM in a linear range from 1.25 to 50 μM. The colorimetric method was simple, selective, and sensitive for glutathione (GSH) detection in the range of 0.25-125 μM with a detection limit (LOD) of 0.12 μM. Thus, we provide a facile synthetic strategy for simultaneously integrating electronic modulation and structural design to develop an efficient MoS 2 -based functional catalyst.