A sandwich-type immunosensor using Pd–Pt nanocrystals as labels for sensitive detection of human tissue polypeptide antigen

A sandwich-type immunosensor was developed for the detection of human tissue polypeptide antigen (hTPA). In this work, a graphene sheet (GS) was synthesized to modify the surface of a glassy carbon electrode (GCE), and Pd–Pt bimetallic nanocrystals were used as secondary-antibody (Ab 2 ) labels for the fabrication of the immunosensor. The amperometric response of the immunosensor for catalyzing hydrogen peroxide (H 2 O 2 ) was recorded. And electrochemical impedance spectroscopy was used to characterize the fabrication process of the immunosensor. The anti-human tissue polypeptide antigen primary antibody (Ab 1 ) was immobilized onto the GS modified GCE via cross-linking with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide (EDC/NHS). With Ab 1 immobilized onto the GS modified GCE and Ab 2 linked on Pd–Pt bimetallic nanocrystals, the immunosensor demonstrated a wide linear range (0.0050–...

Yaoguang Wang, Qin Wei, Yong Zhang, Dan Wu, Hongmin Ma, Aiping Guo and Bin Du

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