Built-in thiol mesoporous carbon immunosensor to detect carcinoembryonic antigen in human serum.

A label-free electrochemical immunosensor for carcinoembryonic antigens (CEA) detection is reported based on a built-in thiol-mesoporous carbon architecture. The material was functionalized with 3-maleimidepropionic acid to immobilize anti-CEA antibodies. The immunosensor was characterized using field-emission scanning electron microscopy, X-ray photoelectron spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. Biorecognition events were monitored by differential pulse voltammetry, with current intensity dependent on protein concentration. The device exhibited a linear range of 1–10 ng mL(-1) for CEA, with a clinically relevant limit of detection of 1.02 ng mL(-1). The immunosensor successfully detected CEA in human serum samples, with results comparable to those obtained by a standard spectrophotometric method. This platform has proven to be a promising alternative for the prognosis and management of patients with colorectal cancer, as well as having significant potential for point-of-care diagnosis. GRAPHICAL ABSTRACT: [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00604-026-07987-8.