Synergistic Strain and Ligand Effects Boosting the Activity of Pt-Based Peroxidase Nanozymes for Femtomolar-Level Colorimetric Immunoassay of Protein Biomarkers

(1.8 fM), representing a ∼20-fold enhancement in sensitivity over the conventional HRP-based CELISA. These discoveries underscore the impact of strain and ligand modulation on enhancing the catalytic activity of nanozymes and highlight their potential as catalytic labels for advancing ultrasensitive bioassay technologies.