Sensitive electrochemical immunosensor for CYFRA21-1 detection based on AuNPs@MoS2@Ti3C2Tx composites.

Cytokeratin fragment antigen 21-1 (CYFRA21-1) is a sensitive marker for detecting non-small cell lung cancer (NSCLC). Ti3C2Tx modified by gold nanoparticles (AuNPs) and molybdenum disulfide (MoS2) were synthesized for the first time to obtain the AuNPs@MoS2@Ti3C2Tx composites, which have large specific surface area and good electrocatalytic properties. A novel electrochemical immunoassay for sensitive detection of CYFRA21-1 was developed by loading a large quantity of secondary antibodies (Ab2) and toluidine blue (TB) on the surface of the material as signal probe, and Nafion-AuNPs mixture as electrode material. When the electrochemical response value of CYFRA21-1 increased linearly within the concentration range of 0.5 pg mL-1-50 ng mL-1, the detection limit can reach as low as 0.03 pg mL-1. In addition, the experimental results showed that the biosensor had the potential to rapidly detect CYFRA21-1 in the complex samples such as patient serum, and had a broad application prospect in the early diagnosis and monitoring of NSCLC.