Electrochemical biosensing, DNA aptamers, Gold nanoparticles, Non-invasive diagnostics, Nanomaterials interaction, Engineering (General). Civil engineering (General), TA1-2040

This study presents a cancer diagnostics method through the development of a graphitic carbon nitride (g-C3N4)-based electrochemical sensor for detecting circulating tumor cells (CTCs) in blood. Utilizing the unique properties of g-C3N4 nanosheets combined with gold nanoparticles functionalized with DNA aptamers, the sensor exhibits remarkable sensitivity and selectivity in CTC detection. The aptamers specifically target cell surface biomarkers, enabling the precise capture and quantification of CTCs. The sensor's detection limit is an impressive 5 cells/mL, with a broad detection range from 10 to 105 cells/mL. This high-performance sensing platform not only achieves rapid and accurate quantification of CTCs but also demonstrates robustness against interference from other cell types, making it highly suitable for clinical applications. The optimized conditions for aptamer-functionalized nanoparticle concentration and incubation time ensure the sensor's efficacy, as validated in spiked blood samples. This work provides a practical and efficient approach for non-invasive cancer diagnostics, offering significant improvements over existing methods in terms of simplicity, sensitivity, and specificity for early detection and monitoring of cancer progression.