Electrochemical immunoplatform for the quantification of epithelial extracellular vesicles applied to prostate cancer diagnosis

Abstract

Prostate cancer (PCa) is the second most commonly diagnosed cancer in men worldwide, and its early detection is critical for improving patient outcomes through timely and effective treatment. In this work, we present the first electrochemical immunoplatform based on magnetic microbeads (MBs) for the determination of epithelial extracellular vesicles (EpEVs), which are emerging as promising biomarkers for PCa diagnosis and prognosis. The immunoplatform employs MBs functionalized with anti-EpCAM antibodies to selectively capture EpEVs, forming sandwich-type immune complexes that are detected via amperometry at disposable screen-printed carbon electrodes. The method demonstrated a detection limit of 0.4 ng µL⁻¹ of EpEVs obtained from PC-3 cell line´s culture, excellent reproducibility (coefficient of variation < 5%), and high selectivity against potential interferences. Comparative analysis with colorimetric immune-magnet ELISA test showed a strong correlation between the two methods, confirming the reliability of the proposed approach. Furthermore, the electrochemical platform provided better precision and a lower limit of detection than the immune magnet ELISA method, indicating its superior analytical performance. Clinical validation using patient samples revealed that the combination of EpEV detection with PSA levels significantly improves the sensitivity and specificity of PCa diagnosis. This novel immunoplatform represents a promising analytical tool for early detection and monitoring of PCa, with potential applications in personalized cancer management.