Guobin Xiong
Thanks to its ease of use, speed, efficiency, and the ability to visually identify detection signals without the need for specialized equipment, lateral flow assay (LFA) technology has become a key analytical method in fields such as pharmaceutical safety testing and biomedicine. Traditional lateral flow assays use colloidal gold as a signal label; however, due to the limited intensity of its colorimetric signal, conventional LFA technology suffers from insufficient sensitivity and fails to meet detection requirements. Based on this, this study synthesized platinum-based bimetallic nanozymes (Pt@Au). Through the synergistic interaction of multiple metal elements, these nanozymes exhibit high enzyme-like catalytic activity. They were then applied to lateral flow assay technology to enable sensitive detection in biosensing. The Pt@Au nanozyme possesses high peroxidase-like catalytic activity, enabling it to catalyze the color-forming substrate TMB within an extremely short time to amplify the signal and achieve sensitive color development. By using an aptamer as an intermediate competitive molecule, streptavidin was conjugated to biotin-DNA molecules on the surface of the Pt@Au nanozyme to competitively detect kanamycin in LFA test strips. The detection linear range is 100 ng/mL to 800 ng/mL. Within the spiked concentration range of 50 to 250 ng/mL, the recovery rates of this method range from 95.1% to 105.2%, with relative standard deviations (RSD) of 3.4% to 8.5%, providing a new technical approach for the rapid on-site detection of antibiotic residues.