PEG-Modified Selenium Nanoparticles Dramatically Increases Antibody Binding Sites for Ultrasensitive Point-of-Care Detection of NT-proBNP

Portable disease monitoring is made possible by point-of-care testing (POCT), which can help prevent clinical deterioration. The widespread adoption of POCT, however, is limited by a shortage of efficient labeling probes. To address this, we developed monodisperse selenium nanoparticles (SeNPs) modified with polyethylene glycol (PEG-SeNPs) to improve their performance as labels. The nanoparticles transform from an aggregated to a monodisperse state after PEG regulation, with an average particle size of 50.23 ± 4.04 nm. This improvement increased the number of antibody binding sites on the surface of each nanoparticle from 34.2 to 91.6. Meanwhile, this study method's sensitivity, stability and accuracy have all greatly increased with the use of artificial intelligence analysis. Relative to conventional lateral flow immunoassay (LFIA) systems, the LOD of this research achieved 0.3 ng/mL for NT-proBNP detection without compromising stability and specificity. Clinical sample validation showed 97.85% agreement with a chemiluminescence immunoassay. As a result, the LFIA platform based on PEG-SeNPs has outstanding analytical performance and is a practical POCT approach for early disease detection, prognostic monitoring and evaluation in illness self-management.