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

• Published in: Nanotechnology Vol. 25; no. 5; pp. 055102 - 6
• Main Authors: Wang, Yaoguang, Wei, Qin, Zhang, Yong, Wu, Dan, Ma, Hongmin, Guo, Aiping, Du, Bin
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 07.02.2014; Institute of Physics
• Subjects: Antibodies, Immobilized; Antigens; Bimetals; Biosensing Techniques - instrumentation; Cross-disciplinary physics: materials science; rheology; Electrochemical Techniques; Exact sciences and technology; Fullerenes and related materials; diamonds, graphite; Graphene; Graphite; human tissue polypeptide antigen; Human tissues; Humans; Immunoassay - methods; Immunosensors; Limit of Detection; Materials science; Metal Nanoparticles - chemistry; Metal Nanoparticles - ultrastructure; Nanocrystalline materials; Nanocrystals; Nanoscale materials and structures: fabrication and characterization; Nanotechnology; Palladium; Pd-Pt; Physics; Platinum; Polypeptides; Reproducibility of Results; sandwich-type immunosensor; Specific materials; Tissue Polypeptide Antigen - analysis; Tissue Polypeptide Antigen - blood; Hydrogen peroxide; Polypeptides; Antibodies; Carbon electrode; Palladium; Selectivity; Sandwich structures; Immunosensor; Hydrochlorides; Graphene; Cross-linking; Biosensor; Biological markers; Vitreous state; Nanostructured materials; Nanocrystal; Electrochemical impedance spectroscopy
• ISSN: 0957-4484; 1361-6528
• DOI: 10.1088/0957-4484/25/5/055102

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 (Ab2) labels for the fabrication of the immunosensor. The amperometric response of the immunosensor for catalyzing hydrogen peroxide (H2O2) was recorded. And electrochemical impedance spectroscopy was used to characterize the fabrication process of the immunosensor. The anti-human tissue polypeptide antigen primary antibody (Ab1) was immobilized onto the GS modified GCE via cross-linking with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide (EDC/NHS). With Ab1 immobilized onto the GS modified GCE and Ab2 linked on Pd-Pt bimetallic nanocrystals, the immunosensor demonstrated a wide linear range (0.0050-15 ng ml−1), a low detection limit (1.2 pg ml−1), good reproducibility, good selectivity and acceptable stability. This design strategy may provide many potential applications in the detection of other cancer biomarkers.