Development of a Sensitive Electrochemical Aptasensor for Non-Small Cell Lung Cancer Extracellular Vesicle Detection

Lung cancer is challenging to diagnose due to late symptom manifestation, necessitating non-invasive, point-of-care detection tools. Extracellular vesicles (EVs), nano-sized particles present in body fluids such as exhaled breath, offer a promising diagnostic route. EVs carry molecular cargo from their parent cells, including cancer-specific protein biomarkers, making them ideal targets for early detection. This study presents an electrochemical aptasensor platform for detecting EVs associated with non-small cell lung cancer. A microfabricated gold chip functionalized with AptTex, a thiol-modified aptamer targeting the CD44 biomarker, is developed. Electrochemical impedance spectroscopy confirms aptamer immobilization, and the platform successfully detectss extracellular vesicles in vitro from non-small cell lung cancer cells with a detection limit of 3.0 × 10⁶ particles/mL and ΔR_et = 476 ± 192 Ω. Calibration plots for generic extracellular vesicles demonstrated a detection limit of 7.0 × 10⁶ particles/mL. The platform shows sensitivity, reproducibility, and minimal sample requirements. These findings demonstrate the potential of this aptasensor for future integration into a portable disease breathalyser, enabling non-invasive early detection of lung cancer.