Dual-Enhanced Lateral Flow Immunoassay: Synergizing Oriented Antibody Anchoring and Nanozyme Catalytic Amplification for Ultrasensitive Cancer Detection.

Abstract

Conventional lateral flow immunoassays (LFIAs) suffer from limited sensitivity in detecting low-abundance tumor biomarkers, primarily attributed to inefficient antibody utilization and insufficient signal intensity of nano-immunoprobes. Here, we propose a dual-enhanced LFIA integrating oriented antibody anchoring and nanozyme catalytic amplification for ultrasensitive visual detection of tumor biomarkers, denoted as DEOAN-LFIA. Bimetallic catalyst gold-platinum nanoparticles (Au@Pt NPs) were functionalized with phenylboronic acid to selectively orient antibodies via fragment crystallizable (Fc) glycans for improving antibody utilization efficiency, thereby enriching target-probe complexes on the test line (T line), realizing the first-step signal amplification. Subsequently, the elevated local concentration of Au@Pt NPs efficiently catalyzed the conversion of chromogenic substrates into colored products, further amplifying the signal from enriched probes on the T line for the second-step signal amplification. Using common tumor markers alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA) as model targets, DEOAN-LFIA achieved ultrasensitive detection of picogram-level targets (50 pg/mL for AFP and 10 pg/mL for CEA) with rapid analysis within 25 min. Clinical validation with 36 human serum samples demonstrated favorable concordance with the standard clinical assay. This DEOAN-LFIA platform provides a robust ultrasensitive point-of-care tool for the early diagnosis of malignant diseases.