Application of a novel and effective aptasensor for electrochemical monitoring of cancer antigen 125 in human serum

Detection of cancer antigen 125 in biological samples is crucial due to its role as a biomarker in the early diagnosis, monitoring, and management of certain cancers, particularly ovarian cancer. This research involved the synthesis and application of an oriented Mn-doped ZnO nanorods composite as a substrate for the development of a biosensor platform to detect ovarian cancer biomarker cancer antigen 125. The synthesized substrate was characterized using various methods. An indium tin oxide electrode modified with Mn-doped ZnO nanorods was used to manufacture a label-free electrochemical aptasensor. The developed assay illustrated a broad linear range from 0.002 ng mL −1 to 3 ng mL −1 with a correlation coefficient of 0.9974 and a low limit of detection (0.5 pg mL −1 ) based on S/N =3. The biosensor was demonstrated satisfactory selectivity when exposed to various common interfering species. The aptsensor also illustrated acceptable reproducibility and high storage stability. Additionally, the potential of this method for early cancer diagnosis was demonstrated by testing the assay on human serum samples, which yielded acceptable recovery values ranging from 97.5 % to 105.0 %. • A new and green strategy was employed for preparation of high stability of carbon dots (CDs). • Notable electrocatalytic property towards paclitaxel oxidation was achieved using the CDs modified sensor. • The applicability of the sensor for paclitaxel detection in human biofluids was successfully assessed.