title: Ultrasensitive enzyme-free immunoassay for squamous cell carcinoma antigen using carbon supported Pd-Au as electrocatalytic labels.
abstract: A novel nonenzymatic sandwich-type electrochemical immunosensor has been developed to detect squamous cell carcinoma antigen (SCCA). Nitrogen-doped graphene sheet (N-GS) was used to increase capacity of capturing primary antibodies (Ab1). Carbon-supported Pd-Au binary nanoparticles (Pd-Au/C) were synthesized and used to label secondary antibodies (Ab2). The specific binding of SCCA and antibodies enabled a quantitative attachment of Pd-Au/C on the electrode surface. Electrocatalytic analysis showed that the prepared Pd-Au/C exhibit excellent electrocatalytic activity towards hydrogen peroxide (H2O2). We use current response of electrocatalytic labels Pd-Au/C to detect the concentration of SCCA. The unique nonenzymatic immunosensor exhibits a relatively wide linear range from 0.005 to 2 ng mL(-1) and high sensitivity with a low detection limit of 1.7 pg mL(-1). The immunsensor also shows good reproducibility (4.2%) and stability (5.8%), which makes it an enormous application prospect in clinical research.
authors.affiliation: Key Laboratory of Chemical Sensing and Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Gao
authors.affiliation: Key Laboratory of Chemical Sensing and Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Du
authors.affiliation: Key Laboratory of Chemical Sensing and Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
authors.forename: Xiaoyue
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Chemical Sensing and Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
authors.forename: Aiping
authors.initials: A
authors.lastname: Guo
authors.affiliation: Key Laboratory of Chemical Sensing and Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Chemical Sensing and Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Wu
authors.affiliation: Key Laboratory of Chemical Sensing and Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
authors.forename: Hongmin
authors.initials: H
authors.lastname: Ma
authors.affiliation: Key Laboratory of Chemical Sensing and Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China. Electronic address: sdjndxwq@163.com.
authors.forename: Qin
authors.initials: Q
authors.lastname: Wei
mesh_terms: D000951:Antigens, Neoplasm / Q000032:analysis*; D015374:Biosensing Techniques; D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D055664:Electrochemical Techniques; D006046:Gold / Q000737:chemistry*; D007118:Immunoassay / Q000379:methods*; D057230:Limit of Detection; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D010165:Palladium / Q000737:chemistry*; D015203:Reproducibility of Results; D015843:Serpins / Q000032:analysis*; D014961:X-Ray Diffraction
chemical_list: D000951:Antigens, Neoplasm; D015843:Serpins; C051072:squamous cell carcinoma-related antigen; D010165:Palladium; D002244:Carbon; D006046:Gold
keywords: Cancer biomarker detection; Electrocatalytic labels; Electrochemical immunosensor; Nitrogen-doped graphene