Development of a labeled-free and labeled electrochemical aptasensor for the detection of cancer antigen 125 by using magnetic g-C3N4/MoS2 nanocomposite

Efficient and timely detection of cancer biomarkers is pivotal for enhancing treatment outcomes and mitigating patient mortality. This study addresses the pressing need for a swift, accurate, and non-invasive method to identify cancer antigen 125 (CA125), a vital biomarker in ovarian cancer. Leveraging the growing prominence of nano-biosensors for their high selectivity and sensitivity, we present the development and characterization of an innovative electrochemical nano-biosensor. The sensor, featuring aptamer strands immobilized on a glassy carbon electrode modified with graphitic carbon nitrides, molybdenum disulfide, and magnetic nanoparticles (g-C₃N₄/MoS₂/Fe₃O₄), demonstrates superior sensitivity and accuracy in CA125 detection. Utilizing methylene blue for electrochemical detection of labeled CA125 and ferrocyanide for label-free detection, our aptasensor achieves a low limit of detection (LOD) at 0.202 U.mL⁻¹ and 0.215 U.mL⁻¹, respectively, with a broad detection range from 2 to 10 U.mL⁻¹. The modified electrode exhibits a pronounced affinity for CA125, demonstrating enhanced stability compared to other biomolecules. Crucially, the evaluation of both patient and normal serum samples underscores the aptasensor's remarkable performance. These findings not only establish a robust foundation for future research in ovarian cancer diagnosis but also highlight the potential clinical impact of our electrochemical nano-biosensor in advancing early cancer detection methodologies.