Ru nanoclusters engineer Prussian blue analog nanocubes for multiple active sites synergistic catalysis enabling high-performance bacterial detection

The timely and specific detection is crucial for determining bacterial illnesses and tracing their source. Nanozyme-based lateral flow immunoassay (LFIA) provides a feasible pathway to improve the sensing performance, but controlling nanozymes’ catalytic capability and employing them for sensitively detecting bacteria are extremely challenging. Herein, a synergistic catalysis nanozyme (PBA@Ru NCs) is designed by doping ruthenium nanoclusters (Ru NCs) on Prussian blue analog nanocubes (PBA NCs) through a self-assembling procedure. According to the theoretical calculation, the Ru NCs will spontaneously dissociate H 2 O 2 to form adsorbed O and H 2 O, which creates a new non-radical pathway to oxidize 3,3′,5,5′-tetramethylbenzidine (TMB) and provides a special route different from PBA NCs to generate OH. This approach overcomes the inherent deficiencies of pure PBA NCs and Ru NCs to achieve good dispersibility, efficient peroxidase-like activity, and enhanced photothermal conversion efficiency. When PBA@Ru NCs are prepared as a detecting probe, the developed LFIA platform achieves a high-sensitive colorimetric assay for Escherichia coli O157:H7, where the naked-eye limit of detection after catalysis is 87 CFU mL −1 , displaying great potential for high-sensitivity bacteria detection. This work provides guidance for constructing nanozymes with efficient catalytic activities and develops their promising applications in the LFIA platform.