Core-shell ZIF-8@Au labels for high-sensitivity lateral flow assays via thiol-functionalization and seed-mediated...

ZIF-8-core/Au-shell (ZIF-8@Au) nanoparticles were fabricated through a two-step strategy involving thiol-modification of ZIF-8 substrates and subsequent Au shell growth via seed-mediated approach, and the ZIF-8@Au nanoparticles were applied to the screening of clostridium difficile infection (CDI). Through regulating dosage of thiol-modifier, we established a surface functionalization protocol that introduced tunable thiol groups onto ZIF-8 particles while preserving their pristine morphology and crystallinity. Subsequent refinement of Au coating parameters enabled the construction of ZIF-8@Au core-shell nanostructures via seed-mediated growth. The resulting ZIF-8@Au nanoparticles were successfully applied to detect biomarkers of CDI, including toxin A, toxin B, and glutamate dehydrogenase (GDH), with sensitivities of 7 pg/mL, 115 pg/mL, and 27 pg/mL, respectively. These results demonstrate the promising potential of this nanoparticle-based platform for lateral flow assays.