An electrochemical aptasensor for thrombin using synergetic catalysis of enzyme and porous Au@Pd core–shell nanostructures for signal amplification

In this work, a sensitive electrochemical aptasensor for thrombin (TB) based on synergetic catalysis of enzyme and porous [email protected] core–shell nanostructure has been constructed. With the advantages of large surface area and outstanding catalytic performance, porous [email protected] core–shell nanostructures were firstly employed as the nanocarrier for the immobilization of electroactive toluidine blue (Tb), hemin/G-quadruplex formed by intercalating hemin into the TB aptamer (TBA) and glucose oxidase (GOx). As a certain amount of glucose was added into the detection cell, GOx rapidly catalyzed the oxidation of glucose, coupling with the local generation of H 2 O 2 in the presence of dissolved O 2 . Then, porous [email protected] nanoparticles and hemin/G-quadruplex as the peroxidase mimics efficiently catalyzed the reduction of H 2 O 2 , amplifying the electrochemical signal and improving the sensitivity. Finally, a detection limit of 0.037   pM for TB was achieved. The excellent performance of the aptasensor indicated its promising prospect as a valuable tool in simple and cost-effective TB detection in clinical application.