A Trinity Strategy to Boost the Catalytic Efficiency of Prussian Blue Nanozyme for Paper-Based Glucose Sensing Devices

The use of artificial enzymes in paper-based sensors is a cost-effective approach for point-of-care testing, yet the limited catalytic activity of nanozymes restricts their biosensing applications. Herein, we employed a trinity strategy to enhance the catalytic activity of Prussian blue nanozymes (PBNZs). The extraneous generation of hydroxyl radicals by cesium-doped PBNZs (CsPB) was confirmed via electron paramagnetic resonance (EPR) spectroscopy. Cs + in the buffer was proved to accelerate the electron transfer. Additionally, CsPB exhibited superior photothermal performance due to improved crystallinity, facilitating the promotion of POD-like activity. Based on this strategy, a paper-based device for rapid glucose sensing (PB-PD) was developed, demonstrating a linear response for glucose concentrations from 0.05 to 20 mM (r 2 > 0.995) with a limit of detection of 33.6 μM, good reproducibility, and excellent storage stability. The PB-PD showed consistent results comparable to commercial strips, indicating strong potential for clinical applications.