A novel biosensor for the monitoring of ovarian cancer tumor protein CA 125 in untreated human plasma samples using a novel nano-ink: a new platform for efficient diagnosis of cancer using paper based microfluidic technology

Abstract

Carcinoma antigen 125 (CA 125) has been recognized as a clinical glycoprotein/biomarker for the early-stage detection of ovarian cancer. Therefore, the precise determination of CA 125 is essential for cancer diagnosis and control. In this study, a novel biosensor was designed for the detection of the CA 125 biomarker in human plasma samples. For this purpose, the anti-CA 125 antibody was immobilized on the surface of the matrix containing Ag–DPA–GQD (silver nanoparticles deposited on the D-penicillamine-functionalized graphene quantum dots) conductive nano-ink modified CysA–Au NPs. The surface morphology of the electrode was investigated via field emission scanning electron microscopy (FE-SEM) and energy dispersive spectroscopy (EDS). The mechanism of nano-ink formation was evaluated via transmission electron microscopy (TEM). Also, the formation of an antigen–antibody complex was monitored using the differential pulse voltammetry (DPV) technique. The engineered immunosensor exhibited good performance with high specificity and sensitivity for the detection of the CA 125 biomarker. Under optimal conditions, the linear range of 0.001–400 U mL⁻¹ and low limit of quantification (LLOQ) 0.001 U mL⁻¹ were obtained. Based on the results, it can be concluded that this immunosensor promisingly has the potential to be employed in the early detection of ovarian cancer in clinical studies.