Fabrication of graphene/MoS2 composite material for enhanced electrochemical sensing of carcinoembryonic antigen in lung cancer detection

Abstract

Carcinoembryonic antigen (CEA) is a widely recognized tumor biomarker that plays a critical role in the early detection and prognosis of several cancers, particularly lung, colorectal, and breast cancer. Accurate and sensitive quantification of CEA levels in biological samples is vital for timely diagnosis and effective treatment monitoring. In this study, we present the development and characterization of a novel electrochemical immunosensor utilizing a three-dimensional graphene/MoS₂ composite for detecting CEA. The composite material was synthesized via a one-step hydrothermal process at 200°C and comprehensively characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) analysis. The hierarchical structure combined a highly porous graphene network with flower-like MoS₂ nanoflowers, demonstrating a 2.8-fold increase in effective electrochemical surface area compared to bare electrodes. Under optimized conditions, the immunosensor achieved sensitive CEA detection with a linear response range of 0.001–150 ng/mL and a detection limit of 0.0006 ng/mL. The sensor showed outstanding selectivity in distinguishing CEA from common interfering substances, with signal fluctuations of less than 5 %. Clinical validation using human serum samples showed strong correlation with standard ELISA methods (r = 0.992) and exceptional recovery rates between 94.2 % and 107.0 %. The developed immunosensor exhibited remarkable stability, maintaining 96 % of its initial response after 1 month of storage, while requiring minimal sample volumes (10 μL) and significantly reduced analysis time (40 min).