Ultrasensitive electrochemical biosensor for des-gamma-carboxy prothrombin analysis based on core-shell Pd@PtCu-alloy loaded on WS2 nanosheet

Herein, a sandwich-type electrochemical biosensor was developed for determination of des-gamma-carboxy prothrombin (DCP). Core-shell [email protected] loaded on WS2 nanosheet ([email protected]2) nanocomposite was lightly synthesized, which possessed large surface area and remarkable peroxidase-like activity, and thus acted as nanocarrier and signal nanoprobe. Secondary DCP antibodies (Ab2) were then tethered on the surface of the nanocomposite, forming the superior label to product and amplify electrochemical signal. Additionally, gold nanoparticles-functionalized multi-wall carbon nanotubes ([email protected]) was employed as the electrode matrix, which could accelerate electron transfer and improve the immobilization of primary DCP antibodies (Ab1). After the typical sandwich-type recognition, an obvious current response was generated through the reduction of hydrogen peroxide (H2O2). With this strategy, the biosensor revealed ultra-sensitivity ranging from 100 fg mL−1 to 100 ng mL−1 with a low limit of detection of 71.6 fg mL−1. What’s more, it was demonstrated to successfully analyze DCP in clinical serum sample. Therefore, the biosensor provided an alternative tool for clinical biomarker analyses.