Ce-MOF@Au-Based Electrochemical\nImmunosensor for Apolipoprotein\nA1 Detection Using Nanobody Technology

Apolipoprotein A1 (Apo-A1) is a well-recognized biomarker\nin tissues,\nclosely associated with cardiovascular diseases such as atherosclerosis,\ncoronary artery disease, and heart failure. However, existing methods\nfor Apo-A1 determination are limited by costly equipment and intricate\noperational procedures. Given the distinct advantages of electrochemical\nimmunosensors, including affordability and high sensitivity, along\nwith the unique attributes of nanobodies (Nbs), such as enhanced specificity\nand better tissue permeability, we developed an electrochemical immunosensor\nfor Apo-A1 detection utilizing Nb technology. In our study, Ce-MOF@AuNPs\nnanocomposites were synthesized by using ultrasonic methods and applied\nto modify a glassy carbon electrode. The Nb6, screened from an Apo-A1\nimmunized phage library, was immobilized onto the nanocomposite material,\nestablishing a robust binding interaction with Apo-A1. The recorded\npeak current values demonstrated a logarithmic increase corresponding\nto Apo-A1 concentrations ranging from 1 to 100,000 pg/mL, with a detection\nlimit of 36 fg/mL. Additionally, the developed immunosensors demonstrated\nhigh selectivity, good stability, and reproducibility. Our methodology\nwas also effectively utilized for serum sample analysis, showing good\nperformance in clinical assessments. This electrochemical immunosensor\nrepresents a promising tool for Apo-A1 detection, with significant\npotential for advancing cardiovascular disease diagnostics.