MoO₃/MIL-125-NH₂ with boosted peroxidase-like activity for electrochemical staphylococcus aureus sensing via specific...

Herein, novel nanozyme mimics MoO₃/MIL-125-NH₂ were reported and conjugated with bacteriophages as a new electrochemical probe for high sensitivity and specific electrochemical detection of staphylococcus aureus. The excellent peroxidase-like activity of MoO₃/MIL-125-NH₂ composites was attributed to the integration of MIL-125-NH₂ with MoO₃, which can boost the generation of superoxide radicals (O• 2^-) and thus promote the oxidation of TMB in the presence of H₂O₂. In this work, two bacteriophages named SapYZU04 and SapYZU10 were isolated from sewage samples by using staphylococcus aureus YZUsa12 as the host. In comparison, MoO₃/MIL-125-NH₂@SapYZU04 was selected as a recognition agent. The DPV current declined linearly with staphylococcus aureus YZUsa12 concentration in the range of 10¹-10⁸ CFU mL^-1, with a low detection limit of 16 CFU mL^-1 (S/N = 3). 20 strains including 13 host strains and 7 non-host strains were used to evaluate the selectivity of the proposed sensor. Regardless of the differences in the degrees of lytic performance for phage SapYZU04, all selected host strains can be screened with merely the same DPV current. Host spectrum-oriented bacteriophage sensing is of great importance for the practical application of bacteriophage-based biosensors in the future.