Pt-Ru bimetallic nanoclusters with super peroxidase-like activity for ultra-sensitive lateral flow immunoassay

In this work, Pt-Ru bimetallic nanoclusters (Pt-Ru NCs) were prepared by a simple one-pot hydrothermal method. The as-prepared Pt-Ru NCs has extremely high peroxidase-like activity, showing a specific activity of 115.36 U/mg far superior to Pt NCs and many reported single-atom nanozymes. This can be attributed to the various microstructures effective for catalysis and unique electron transfer characteristics leading to active hydroxyl radicals (OH) activation as revealed by density functional theory. By using the Pt-Ru NCs as a substitute for natural horseradish peroxidaseand when cross-linking with antibody as a catalytic label, the colorimetric enhanced lateral flow immunoassay (LFIA) for D-dimer detection was established. As a result, with only 20 s of additional coloration, the visual sensitivity can be improved by about 100 times to 1 ng/mL, while maintaining good specificity and anti-interference. In general, the excellent performance indicates that the Pt-Ru NCs have great potential in colorimetric detection, which is worthy of further promotion.