Ultrasensitive non-mediator electrochemical immunosensors using Au/Ag/Au core/double shell nanoparticles as enzyme-mimetic labels.
Determination of squamous cell carcinoma antigen (SCCA) in human serum plays an important role in diagnosis of cervical squamous cell carcinoma. In this work, Au/Ag/Au core/double shell nanoparticles (Au/Ag/Au NPs) were prepared by a simple approach and were used as novel enzyme-mimetic labels for development of a sandwich-type electrochemical immunosensor for SCCA. The nanostructure of Au/Ag/Au NPs could be well confirmed by transmission electron microscope (TEM) and UV-vis spectra. Au NPs decorated mercapto-functionalized graphene sheets (Au@SH-GS) were used as platform for immobilization of primary antibody (Ab1), while Au/Ag/Au NPs were employed as labels of secondary antibody (Ab2). Due to the excellent electrocatalytic activity of Au/Ag/Au NPs towards the reduction of hydrogen peroxide (H2O2), electrochemical amperometric responses to SCCA were achieved after the immuno-reaction. Under optimum conditions, the electrochemical immunosensor exhibited a wide linear range from 0.5 pg/mL to 40 ng/mL with a low detection limit of 0.18 pg/mL for SCCA. The designed immunosensor displayed an excellent analytical performance with good reproducibility, high selectivity and stability.
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
Yulan
Y
Wang
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
Yong
Y
Zhang
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
Yu
Y
Su
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
Feng
F
Li
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
Hongmin
H
Ma
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
He
H
Li
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
Bin
B
Du
Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China. Electronic address: sdjndxwq@163.com.
Qin
Q
Wei
D055910:Antibodies, Immobilized / Q000737:chemistry / Q000276:immunology; D000951:Antigens, Neoplasm / Q000097:blood / Q000276:immunology; D015374:Biosensing Techniques / Q000379:methods*; D055664:Electrochemical Techniques / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D007118:Immunoassay / Q000379:methods*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D010084:Oxidation-Reduction; D015203:Reproducibility of Results; D015843:Serpins / Q000097:blood / Q000276:immunology; D012834:Silver / Q000737:chemistry*; D013053:Spectrophotometry
D055910:Antibodies, Immobilized; D000951:Antigens, Neoplasm; D015843:Serpins; C051072:squamous cell carcinoma-related antigen; D012834:Silver; D006046:Gold; D006108:Graphite; D006861:Hydrogen Peroxide
Cancer diagnosing; Core/shell nanoparticle; Electrochemical immunosensor; Enzyme-mimetic label; Hydrogen peroxide