Mesoporous magnetic nanoparticles conjugated aptamers for exosomes capture and detection of Alzheimer's disease

Exosomes are nanoscale membrane-enclosed extracellular vesicles secreted by various cells, which have enormous potential as disease biomarkers for clinical application. However, the isolation and detection of exosomes remain enormous challenges, which limits their further application. Herein, inspired by immunomagnetic beads, a magnetic nanoparticle conjugated aptamer was repurposed for the effective capture and detection of exosomes. The magnetic nanoparticles, composed of Fe₃O₄ synthesized by the hydrothermal method as the core and coupled with gold nanoparticles (Fe₃O₄@Au), provide a large specific surface area, making the resulting composite material an effective platform for exosome capture. Furthermore, the elution of captured exosomes with 1.0 M NaCl made downstream analysis of exosomes possible. The preliminary clinical application value of the composite in exosome analyses of serum from healthy individuals and patients with Alzheimer's disease (AD) has also been verified, which could provide a promising platform for biomedical and clinical diagnosis.