Labeled sandwich-type electrochemical immunosensor based on TiCT/AuNP and TiCT/HKUST-1/TB composites for early liver cancer detection.

A novel sandwich-type electrochemical immunosensor for the detection of the liver cancer marker alpha-fetoprotein (AFP) in human serum is proposed. The two-dimensional MXene material TiCT was first prepared using etching and ultrasonic stripping, and then TiCT was used to reduce chloroauric acid to form TiCT/AuNP composites which were modified on the surface of the glassy carbon electrodes to form probe-type sensors. The TiCT/AuNPs provide a large number of binding sites for the AFP capture antibody (Ab1) and increase the electrochemical reaction active site. The TiCT/copper metal-organic frameworks HKUST-1 composite was also prepared by solvothermal method and combined with toluidine blue (TB) and AFP detection antibody (Ab2) to form a labeled sandwich-type electrochemical immunosensor. The sensor achieved trace detection of AFP from 0.1 to 100 ng/mL with a detection limit of 0.073 pg/mL and possesses good selectivity, stability, and reproducibility. The sensor performs well in clinical samples and has good potential for clinical applications.