Reduced graphene oxide based ultrasensitive resistive sensor for detection of CA125

Early-stage detection of any cancer significantly improves the survival rates by enabling clinicians to design simpler and more effective treatment options, leading to a cure or remission. Early diagnosis of ovarian cancer, the leading cause of gynaecological cancer related mortalities, relies heavily on accurate detection of the serum biomarker CA125. This work presents a simple rGO/monoclonal antibody (mAB)/bovine serum albumin (BSA) based 2-port resistive sensor for CA125. The binding of mAB on rGO was confirmed by atomic force microscopy which showed increase in thickness of the device from 1.4 nm to approximately 40–60 nm after the mAB anchored on the device. FESEM further confirmed the morphologies of rGO, rGO/mAB, and rGO/mAB/CA125. The sensor exhibited impressive response ranging from 1.28% to 113.4% for 1 pg/mL to 300 ng/mL CA125. Notably, the rGO/mAB/BSA sensor displayed high selectivity towards CA125 and a readout circuit was designed, assembled, and tested with the sensors to get a portable device for detecting CA125. The developed sensors were tested with 9 clinical samples and were found to be determining the CA125 concentration accurately.