Ultrasensitive analysis of carcinoembryonic antigen based on MoS-based electrochemical immunosensor with triple signal amplification.

Ultrasensitive detection of cancer biomarkers has shown great promise for precision medicine. Here, a triple signal amplification strategy was developed for analysis of carcinoembryonic antigen (CEA) by using MoS-based nanocomposites. Gold nanoparticles-decorated molybdenum disulfide nanocomposite (MoS-AuNPs) was used to construct the modified electrode and nanoprobe, which could efficiently amplify electrochemical signal due to its large surface area and high catalytic ability. Horseradish peroxidase (HRP)-labelled carcinoembryonic monoclonal antibody (anti-CEA) and HRP were used to co-construct the MoS-based nanoprobe, which could further amplify the electrochemical signal by catalyzing o-phenylenediamine (o-PD) in the presence of hydrogen peroxide (HO). Expectedly, an excellent analytical performance for CEA detection was obtained, such as wide detection range (10 fg mL-1 ng mL), ultralow detection limit (1.2 fg mL), high selectivity and good stability, suggesting this immunosensor could detect CEA in real samples.