Amperometric sandwich‐type aptasensor based on peroxidase mimetic Au@Pt for the carcinoembryonic antigen

For sensitive analysis of cancer biomarker carcinoembryonic antigen (CEA), an amperometric sandwich‐type aptasensor is proposed based on a signal amplification strategy of Au@Pt bimetallic nanoprobes. As the excellent catalytic activity to hydrogen peroxide (H2O2), core‐shell Au@Pt nanoparticles are employed as nanoprobes by conjugating directly with the secondary aptamer of CEA (Apt‐II). Due to the synergic recognition effect of dual aptamers and the excellent catalytic activity of nanoprobes, this amperometric sandwich‐type aptasensor for CEA exhibits high specificity and good sensitivity with a limit of detection of 0.31 ng/mL, along with a wide linear range from 0.1 ng/mL to 100 ng/mL.