Antibody-modified 2D MXene nanosheet probes for selective, picolevel detection of cancer biomarkers.

Cancer biomarkers are crucial indicators found in clinical samples, playing a key role in early detection, diagnosis, and treatment of cancer. Detecting these biomarkers with high sensitivity is essential for early diagnosis, especially in aggressive cancers like lung cancer, which is the leading cause of cancer-related deaths. Carcinoembryonic antigen (CEA) is a critical biomarker for lung cancer, and its detection aids in identifying the disease at an early stage. Electrochemical sensing, known for its high sensitivity and rapid response, has shown great promise in cancer biomarker detection. MXenes, two-dimensional materials composed of carbides and nitrides, offer excellent electrochemical performance due to their high surface area and conductivity. In this study, MXenes were modified via hydrothermal treatment to produce MXene nanosheets (MNS) with increased interlayer spacing, enhancing their electron transfer capabilities. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) revealed the superior electrochemical properties of MNS compared to pristine MXene. These MNS were functionalized with CEA-specific antibodies using EDC-NHS chemistry, creating a highly specific electrochemical biosensor for CEA detection. The sensor exhibited a remarkable limit of detection at the picogram level and was validated through real-time blood analysis, achieving a 95% recovery rate. This MNS-based biosensor demonstrates significant potential for clinical diagnostics, particularly for the early detection of cancer biomarkers, paving the way for improved cancer treatment outcomes.