Simplified synthesis of self-propelled fluorescent probes with controlled motility based on bifunctional platinum clusterzymes for enhanced arthritis monitoring

Fluorescent micro/nanomotors with self-propelled features hold great potential as next-generation probes for versatile bioanalytical applications, but the complex fabrication process and insufficient motion control largely restrict their practical use. Herein, we report a new strategy of constructing self-propelled probes by leveraging fluorescent platinum nanoclusters (PtNCs) with intrinsic catalase-mimic property, which greatly simplifies the fabrication process and enables precise control of their motility. Upon asymmetrically assembling PtNCs onto dendritic silica nanoparticles, fluorescent Janus-structured nanomotors can be obtained, wherein PtNCs act as both nanozymes for H₂O₂-powered propulsion and fluorescent reporters for further optical sensing. These fluorescent nanoprobes exhibit remarkably enhanced mobility (0.508 µm² s⁻¹) in the presence of H₂O₂ due to the catalytic self-diffusiophoresis mechanism. Importantly, the motility of these bifunctional clusterzyme-empowered fluorescent nanomotors can be precisely modulated by their size, as validated through both spectroscopic analysis and computational simulation. Furthermore, an enhanced fluorescent sensing platform was constructed by leveraging these PtNC clusterzyme-based self-propelled probes, which demonstrated a 13-fold lower detection limit and much faster response than the static systems for detecting pyrophosphate ions, an important arthritis biomarker. This study establishes a new paradigm in the design of robust self-propelled nanoprobes by harnessing the unique properties of bifunctional metal clusterzymes for diverse applications.