4315684

Catalytic silver-platinum hollow nanoparticles as labels for sensitive colorimetric lateral flow assay

Date
August 18, 2025

Colorimetric lateral flow assays (CLFAs) have been widely recognized as point-of-care diagnostic tools due to their rapid response, simplicity, affordability, and user-friendly operation. Nevertheless, commercially available CLFA primarily rely on the plasmonic properties of gold nanoparticles (Au NPs), whose detection sensitivity is intrinsically limited by nanoparticle size. This limitation significantly restricts the capability of conventional AuNP-based CLFAs to detect biomarkers at low concentrations. To address this challenge, we introduce a novel CLFA system utilizing catalytic silver-platinum hollow nanoparticles (Ag-Pt HNPs) as labels. These nanoparticles were synthesized through a galvanic replacement reaction between Ag nanoparticles and Pt2+ ions, resulting in hollow nanostructure exhibiting robust peroxidase-like activity toward the oxidation of TMB by H2O2. Owing to their hollow architecture and predominant composition of inexpensive silver, the Ag-Pt HNPs served as a cost-effective alternative to conventional solid Au NPs in CLFA. The colorimetric signal generated by Ag-Pt HNPs on the test strip can be significantly amplified through a simple peroxidase substrate treatment process within 5 minutes. When applied to detect prostate-specific antigen (PSA), the Ag-Pt HNP-based CLFA demonstrated over 20-fold higher sensitivity compared to conventional Au NP-based assays. The clinical applicability of this CLFA system was further validated through spiked human serum and patient samples, demonstrating consistent analytical recovery and reliability. The combined advantages of improved sensitivity and cost-effectiveness position Ag-Pt HNP-based CLFAs as promising candidates for next-generation diagnostic tools, especially in resource-limited settings.

Presenter

Co-Authors

Speaker Image for Xiaohu Xia
Associate Professor, University of Central Florida

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Metallic nanoparticles (NPs) with hollow interiors often exhibit superior plasmonic properties compared to their solid counterparts. Among various types, gold and silver hollow NPs have been extensively developed due to their remarkable plasmonic activity and ease of synthesis…