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.