Hemin-functionalized MoS2 nanosheets: enhanced peroxidase-like catalytic activity with a steady state in aqueous solution

Hemin-functionalized MoS2 nanosheets (hemin/MoS2-NSs) are first obtained via van der Waals interactions between few-layered MoS2 nanosheets (MoS2-NSs) and hemin molecules. It is demonstrated that a portion of MoS2-NSs undergoes a phase transition from semiconducting to metallic phase under the influence of hemin, which shows the coexistence of semiconducting and metallic phases in the crystal structure of hemin/MoS2-NSs. MoS2-NSs prepared from sonication-induced exfoliation of bulk MoS2 crystals in aqueous surfactant solution exhibit intrinsic peroxidase-like activity for the oxidation of 3,3,5,5-tetramethylbenzidine in the presence of H2O2, which is further improved by the functionalization of hemin. Significantly, MoS2-NSs are presented as a new support of hemin, and when compared to MoS2-NSs, hemin/MoS2-NSs exhibit better dispersity in aqueous solution, which is used in the development of H2O2 sensor based on the enhanced peroxidase-like activity.