Non-small cell lung cancer (NSCLC) is still the leading cause of lung cancer-related deaths globally, affecting both men and women. Mutations in the epidermal growth factor receptor (EGFR) are most common among patients with NSCLC, especially Asian patients. Here, we introduce an electrochemical capacitive biosensor for the early detection of NSCLC through specific identification of EGFR. A novel and reagentless EGFR aptamer was designed using the systematic evolution of ligands by exponential enrichment (SELEX) process and immobilized on a chromium (Cr)/gold (Au) electrode, with capacitance signals used for detection. The biosensor employs an interdigitated capacitor electrode (IDCE) functionalized with 3-mercaptopropionic acid (MPA), enhancing EGFR aptamer immobilization, while 6-mercapto-1-hexanol (MCH) was used for effective blocking to ensure robust and high-affinity binding to target analytes. The IDCE capacitive biosensor achieved real-time rapid detection within 3 s and demonstrated a detection limit of 0.005 ng/mL for the EGFR peptide, with a dynamic range of 10