Development of an electrochemical immunosensor for Lipoprotein-associated phospholipase A2 detection based on AuPdNPs@GO-MWCNTs and high-affinity monoclonal antibodies

High-affinity LP-PLA₂ mAb and AuPdNPs@GO-MWCNTs are fabricated to immobilize antibodies and amplify electrochemical signals. • A label-free competitive DPV immunosensor for LP-PLA 2 achieves a low LOD of 0.30 ng/mL with a linear range covering clinical concentrations. • The immunosensor exhibits favorable repeatability, stability and selectivity, and its clinical test data well matches standard chemiluminescence results. • The rapid sensitive platform distinguishes LP-PLA₂ positive/negative samples and has promising prospects for early atherosclerosis diagnosis. Lipoprotein-associated phospholipase A2 (Lp-PLA2) has emerged as a novel and critical clinical biomarker for vascular inflammation of atherosclerosis and cardiovascular disease risk assessment. However, current detection methods often face challenges regarding sensitivity, cost-effectiveness or complex operational procedures. Herein, a highly sensitive and selective electrochemical immunosensor was developed for the quantitative determination of Lp-PLA2. In this study, the sensing platform leverages the synergistic effect of AuPdNPs@GO-MWCNTs composites and high-affinity monoclonal antibodies. Firstly, the AuPdNPs@GO-MWCNTs was synthesized and characterized via SEM, EDS and XRD, which provided abundant electroactive sites and accelerated interfacial electron transfer. Subsequently, the maturely prepared Lp-PLA2 mAbs were immobilized onto the modified electrode surface to ensure specific molecular recognition. Under optimized experimental conditions, the proposed immunosensor exhibited a wide linear range from 1 to 2000 ng/mL, with a remarkably low limit of detection (LOD) of 0.3 ng/mL (S/N = 3). Furthermore, the sensor demonstrated excellent reproducibility, long-term stability, high selectivity against common interfering substances in serum and reliable detection recovery rate (97.21%–100.59%). As a result, the practical applicability of the biosensor was validated using real clinical samples, showing a high correlation with standard clinical assays. This study presents a robust platform for the rapid detection of Lp-PLA2 and demonstrates the promising potential of AuPdNPs@GO-MWCNTs in enhancing the performance of electrochemical diagnostic systems. Download: Download high-res image (143KB) Download: Download full-size image