Electrochemical immunosensor based on Pd@Pt/MoS2-Gr for the sensitive detection of CEA

Here, a BSA/anti-CEA/Pd@Pt/MoS2-Gr/GCE electrochemical immunosensor was constructed to quantitatively detect CEA. By using graphene as a growth framework, the introduction of molybdenum disulfide (MoS2) effectively solves the problem of easy accumulation of graphene during hydrothermal reduction and self-assembly. Also, it increases the specific surface area and electrochemical performance. The core-shell Pd@Pt composite metal nanoparticles with obvious concavity on the outer surface can provide larger specific surface area, higher conductivity, more catalytic active sites, better biocompatibility, and other advantages. MoS2-Gr also solves the problem of low direct loading of precious metal nanoparticles. Applying the modification materials Pd@Pt/MoS2-Gr to the electrode, the prepared elctrochemical immunosensor has a detection limit of 0.005 pg/mL for CEA and a linear range of 0.00001-100 ng/mL; meanwhile, it shows good selectivity, reproducibility, and stability that achieve effective and accurate detection of CEA.