Highly efficient and label-free sensitive detection of tumor-derived exosome with an aptasensor-based microfluidic chip

Exosomes are cell-secreted vesicles that facilitate intercellular communication by transferring information between cells. Tumor cells release more exosomes containing tumor genetic information in low-oxygen environments, making tumor-derived exosomes (TEX) promising biomarkers. Nevertheless, developing a high-sensitivity and convenient exosome detection method remains a challenging and valuable pursuit in clinical applications. Here, we proposed a novel microfluidic chip that incorporated a microelectrode sensor modified with EpCAM aptthis aptasensor-based microfluidic chip provided a precise platform for the rapid and selective detection of TEX detectionamer, leading specifically efficient enrichment and sensitive label-free detection of TEX. The relative impedance variation from electrochemical impedance spectroscopy (EIS) of microelectrode system after capture of TEX was ultilized for quantifying concentration of exosomes. The inclusion of a herringbone structure in the chip significantly enhanced the capture efficiency of TEX, enabling highly sensitive detection of TEX with a limit of detection (LOD) of 1.4 × 104 particles/mL in a wide linear range from 1.0 × 105 to 1.0 × 109 particles/mL (R2 = 0.994). For testing TEX in serum samples, this aptasensor based platform demonstrated excellent selectivity, stability and remarkable reproducibility, with relative standard deviation (RSD) of 4.37 %. The comparison of the TEXs testing with this chip showed a significant difference between lung cancer patients and healthy controls. Overall, this aptasensor-based microfluidic chip provided a precise platform for the rapid and selective detection of TEX detection, holding significant potential for clinical diagnosis and medical research.