Oxidase activity-enhanced manganese (III) oxide nanozyme grown in dendritic mesoporous silica nanoparticles for sensitive lateral flow immunoassay of C-reactive protein.

The development of cost-effective nanozymes with signal amplification function to overcome the limited sensitivity of lateral flow immunoassays (LFIAs) is of great significance. Here, we introduce the first Mn2O3-based colorimetric LFIA platform for sensitive C-reactive protein (CRP) detection. By confining Mn2O3 within dendritic mesoporous silica nanoparticles (DMSNs), DMSN-Mn2O3 nanozymes have been synthesized with enhanced active site exposure and uniform particle sizes. It is demonstrated that DMSN-Mn2O3 exhibits better catalytic performance compared to DMSN-MnO2 and pure Mn2O3, showing the importance of control over both composition and nanostructure in enhancing the nanozyme functions. In the built H2O2-free colorimetric LFIA platform, DMSN-Mn2O3 demonstrates rapid catalytic amplification (30 s) for CRP detection, achieving a limit of detection of 0.25 ng mL-1, a 6-fold improvement over conventional colloidal gold-based LFIAs. This work contributes to the rational design of high-performance nanozymes and provides a platform technology for point-of-care diagnostics with enhanced sensitivity.