Bifunctional Fe-Doped MoS₂ Nanozyme for DNA-Engineered Protein Discrimination and Photothermally Enhanced Bacterial...

The accurate identification of multiple proteins and effective eradication of bacteria hold paramount importance for clinical diagnosis and oral disease prophylaxis. Although molybdenum disulfide (MoS₂) nanomaterials possess exceptional physicochemical properties that offer distinct advantages in bioanalysis and antibacterial fields, their low photogenerated carrier mobility and limited active site density have restricted their widespread application. Herein, we report the synthesis of Fe-doped MoS₂ (Fe-MoS₂) nanomaterials via a facile one-step solvothermal method. The incorporation of Fe preserved the two-dimensional layered structure of MoS₂ while provoking a morphological transformation into irregular dendritic nanostructures. The resulting Fe-MoS₂ demonstrated superior peroxidase-like activity with a higher affinity for H₂O₂ compared with both natural horseradish peroxidase (HRP) and other nanozymes. More intriguingly, single-stranded DNA (ssDNA) ligands enabled precise tuning of the catalytic activity of Fe-MoS₂ in a base- and length-dependent manner. Leveraging this tunability, we constructed a colorimetric sensor array using polycytosine (C6/C15/C45)-functionalized Fe-MoS₂, which discriminated eight proteins with high precision and good sensitivity, successfully distinguished binary mixtures, and accurately identified proteins in human urine samples. In addition, Fe-MoS₂ exhibited excellent photothermal properties that synergistically enhanced its peroxidase-mimicking activity under near-infrared (NIR) irradiation. Based on this dual functionality, Fe-MoS₂ achieved near-total eradication of Streptococcus mutans (S. mutans) and 90% clearance of its biofilm. This work presents Fe-MoS₂ as a bifunctional nanoplatform for biomedical diagnostics and oral therapy, highlighting its potential in precision medicine and infectious disease management.