Sandwich-type electrochemical immunosensor constructed using three-dimensional lamellar stacked CoS2@C hollow nanotubes prepared by template-free method to detect carcinoembryonic antigen

Effective treatment of cancer depends on early detection of tumor markers. In this paper, an effective template-free method was used to prepare CoS 2 @C three-dimensional hollow sheet nanotubes as the matrix of the immunosensor. The unique three-dimensional hybrid hollow tubular nanostructure provides greater contact area and enhanced detection limit. The CoS 2 @C–NH 2 -HRP nanomaterial was synthesized as a marker and had a high specific surface area, which can effectively improve the electrocatalytic ability of hydrogen peroxide (H 2 O 2 ) reduction while increasing the amount of capture-fixed carcinoembryonic antigen antibody (anti-CEA). In addition, the co-bonded horseradish peroxidase (HRP) can further promote the redox of H 2 O 2 and amplify the electrical signal. Carcinoembryonic antigen (CEA) was quantified by immediate current response (i-t), and the prepared immunosensor had good analytical performance under optimized conditions. The current signal and the concentration of CEA were linear in the range of 0.001–80 ng/mL, and the detection limit was 0.33 pg/mL (S/N = 3). The designed immunosensor has good selectivity , repeatability and stability, and the detection of human serum samples shows good performance. Furthermore, electrochemical immunosensor has broad application prospects in the clinical diagnosis of CEA.