Highly sensitive chemiluminescence immunoassay utilizing functionalized magnetic metal-organic framework materials for the detection of CEA and CA199.

BACKGROUND

In response to the urgent need for highly sensitive and rapid combined detection of multiple tumor markers for the early diagnosis of colorectal cancer, this work innovatively constructs a magnetically-driven chemiluminescence (CL) immunosensing platform (CoFe2O4@ZIF-8/luminol-Au NPs).

RESULTS

CoFe2O4 NPs were firstly aminated via solvothermal method and lysine modification to provide specific binding sites. ZIF-8 was then grown in situ to form a core-shell structure with high specific surface area for efficient luminol loading. Finally, Au NPs were generated in situ within ZIF-8, simultaneously immobilizing luminol to form composite signal units. This design integrates magnetic separation, confinement effects, and signal amplification, generating an ideal microenvironment for enhanced CL reactions. The label-free CL immunoassay achieves an impressive limit of detection (LOD) of 22 fg/mL for CEA and 5.4 fg/mL for CA199, with broad linear ranges spanning over 5 orders of magnitude. The entire detection process is completed within 30 min, and the analysis of real serum samples demonstrates good recoveries.