Ultrasensitive non-mediator electrochemical immunosensors using Au/Ag/Au core/double shell nanoparticles as enzyme-mimetic labels

作者：Wang Yulan; Zhang Yong; Su Yu; Li Feng; Ma Hongmin; Li He; Du Bin; Wei Qin^*

来源：Talanta, 2014, 124: 60-66.

DOI：10.1016/j.talanta.2014.02.035

• Cancer diagnosing
• Electrochemical immunosensor
• Enzyme-mimetic label
• Core/shell nanoparticle
• Hydrogen peroxide

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 (Ab(1)), while Au/Ag/Au NPs were employed as labels of secondary antibody (Ab(2)). 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.

• 出版日期2014-6-15
• 单位山东大学; 济南大学