An electrochemical aptasensor based on g-C3N4/Fe3O4/PANI nanocomposite applying cancer antigen_125 biomarkers detection

Early detection can help control and treat ovarian cancer, which is one of the most deadly types of cancer among women. Nowadays, nanobiosensors as a time-saving tool with highly selective and sensitive properties applied in different biomarker detection. One of the most sensitive methods for diagnosing ovarian cancer is electrochemistry-based methods. This study was conducted to detect ovarian cancer antigen 125 (CA125) bio-markers using an electrochemical aptasensor based on voltammetric techniques. Graphitic carbon nitrides, magnetic nanoparticles, and polyaniline (g-C3N4/Fe3O4/PANI) were utilized to stabilize aptamer chains on the surface of a gold electrode (GE). The hexacyanoferrate redox system was used as the electroactive probe, and it was typically operated at around 0.3 V (vs. Ag/AgCl), with a 0.418 U.mL-1 detection limit in the hex-acyanoferrate medium. As a redox-active medium, methylene blue was used to lower the electrochemical po-tential for the detection of CA125. The detection potential was reduced to -0.2 V, and the electrochemical aptasensor exhibited a broad dynamic linear range (DLR) ranging between 5 and 60 U.mL-1, with an R2 of 0.993 and a limit of detection (LOD) of 0.298 U.mL-1. The results revealed that the modified electrode is highly se-lective for CA125 compared with other biomolecules. Additionally, the synthesized aptasensor exhibited excellent selectivity and stability. This electrochemical aptasensor demonstrated outstanding results for evalu-ating the serum of patients and healthy people.