A label-free electrochemical immunosensor for the detection of cancer biomarker alpha-fetoprotein (AFP) based on hydroxyapatite induced redox current

作者：Sun, Jisan; Tian, Dazhi; Guo, Qingjun; Zhang, Li; Jiang, Wentao^*; Yang, Minghui^*

来源：Analytical Methods, 2016, 8(40): 7319-7323.

DOI：10.1039/c6ay02555b

• SENSING PLATFORM
• QUANTUM DOTS
• SIGNAL AMPLIFICATION
• SILVER NANOCLUSTERS
• TUMOR-MARKER
• HUMAN SERUM
• IMMUNOASSAY
• NANOPARTICLES
• ANTIGEN
• STRATEGY

A sensitive and selective electrochemical immunosensor for label-free etection of cancer biomarker alpha-fetoprotein (AFP) was developed based on hydroxyapatite (HAP) nanoparticles induced electrochemical current. HAP nanoparticles and graphene oxide (GO) were co-immobilized onto an electrode surface to modify the electrode. The phosphate groups contained in the HAP nanoparticles can react with molybdate to form redox molybdophosphate precipitates on the electrode surface, generating electrochemical current. GO enhanced the electrochemical current intensity due to its good conductivity. The following immobilization of the anti-AFP antibody and capture of AFP resulted in the formation of an immuno-complex layer on the electrode. This immuno-complex layer prevented the reaction of hydroxyapatite nanoparticles with molybdate, leading to the decrease of the electrochemical current, and the current change is proportional to the concentration of AFP detected. A wide linear range (0.01-10 ng mL(-1)) and low detection limit (5 pg mL(-1)) towards AFP detection were obtained. The reliability of the proposed immunosensor was evaluated by the detection of AFP in human serumsamples. This study demonstrated the potential of the developed immunosensor in ultrasensitive detection of AFP or other biomarkers.

• 出版日期2016
• 单位天津市第一中心医院; 中南大学