<p>The cancer cell membrane, rich in tumor-associated antigens, effectively replicates the characteristics of cancer cells by presenting specific protein profiles. Leveraging the inherent binding capability of the cancer cell membrane, here we show a homotypic membrane-powered biomimetic interface for subtype-specific analysis of breast cancer extracellular vesicles (EVs). Specifically, the breast cancer cell membrane is employed to coat a gold substrate, thereby forming the biomimetic interface capable of selectively binding breast cancer EVs with similar subtype features. Subsequently, silver nanoparticles-tethered antibodies are adopted as electroactive immunoprobes to label these EVs, generating distinct electrochemical signals for quantitative analysis. Research findings demonstrate high selectivity and sensitivity of the interface for analyzing target EVs. Based on this, an electrochemical microfluidic device is developed and validated for its effectiveness in identifying subtype features of breast cancer patients. Therefore, our work provides a simple yet efficient platform for precise cancer diagnosis and personalized treatment.</p>