Portable electrochemical immunosensor for point-of-care testing of ovarian cancer biomarker HE4 in commercial human blood serum samples

Abstract Ovarian cancer ranks as the seventh most prevalent malignancy among women globally. Human epididymis protein 4 (HE4) is an FDA-approved tumor biomarker for the early detection of malignant ovarian cancer. In this work, a portable, electrochemical HE4 immunosensor was fabricated for the rapid, sensitive, and practical analysis of HE4 levels in commercial human blood serum. In the preparation of immunosensors, nanomaterials such as Ti 3 C 2 , Ti 3 C 2 -COOH, and gold nanoparticles (AuNPs), as well as disposable screen-printed carbon electrodes, were used. The influence of nanomaterials on the electrochemical efficiency of electrodes and immunosensors was examined. The materials of Ti 3 C 2 , Ti 3 C 2 -COOH, and AuNP, and the modified electrodes with these materials, were characterized by FE-SEM-EDX, FTIR, and XRD. Optimization studies and evaluation of analytical performance of the HE4 immunosensor were conducted using a portable electrochemical reader with DPV. The linear range and the detection limit of HE4 immunosensors were determined to be 5–250 pM and 0.34 pM, respectively. Stability was observed for 60 days, and shelf life was assessed for 24 weeks. The selectivity of HE4 immunosensors was tested in the presence of other ovarian cancer biomarkers and found to be highly selective for HE4. In repeatability tests, HE4 immunosensors responded to seven repetitions (RSD: 3.38%, n = 7). Method validation of the immunosensor platform was confirmed by ELISA. The HE4 levels in commercial human blood serum were directly measured on-screen in picomolar (pM) (immunosensor setup time: 105 min; antibody-antigen-BSA incubations) and a portable electrochemical reader (device reading time: 20–30 s). The developed HE4 immunosensors are potential candidates in point-of-care testing. Graphical abstract