title: Sensitive sandwich electrochemical immunosensor for alpha fetoprotein based on prussian blue modified hydroxyapatite.
abstract: A sandwich electrochemical immunosensor for the sensitive determination of alpha fetoprotein (AFP) has been fabricated. Prussian blue modified hydroxyapatite (PB@HAP) was firstly prepared and used as electrochemical label due to the wonderful conductivity and good biocompatibility of HAP. The results proved that the immunosensor fabricated using the label based on PB@HAP loaded with horse radish peroxidase (HRP) and secondary anti-AFP antibody (Ab(2)) (PB@HAP-HRP-Ab(2)) had high sensitivity, and the sensitivity of the label PB@HAP-HRP-Ab(2) was much higher than labels of PB@HAP-Ab(2), PB-HRP-Ab(2) and HAP-HRP-Ab(2). The mixture of graphene sheet (GS) and thionine (TH) was not only used to immobilize anti-AFP antibody (Ab(1)) but also took part in the signal amplification. The amperometric signal increased linearly with AFP concentration in the range of 0.02-8 ng/mL with a low detection limit of 9 pg/mL. The immunosensor had the advantages of high sensitivity, good selectivity and good stability, and was applied to the analysis of AFP in serum sample with satisfactory results. Due to the low-cost and easy synthesis of PB@HAP, the screen-printed electrodes could be used instead of the bare glass carbon electrode in order to achieve mass production. In addition, it had potential application in the detection of other tumor markers.
authors.affiliation: School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, People's Republic of China.
authors.forename: Yuxue
authors.initials: Y
authors.lastname: Dai
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Cai
authors.forename: Yanfang
authors.initials: Y
authors.lastname: Zhao
authors.forename: Dan
authors.initials: D
authors.lastname: Wu
authors.forename: Bao
authors.initials: B
authors.lastname: Liu
authors.forename: Ru
authors.initials: R
authors.lastname: Li
authors.forename: Minghui
authors.initials: M
authors.lastname: Yang
authors.forename: Qin
authors.initials: Q
authors.lastname: Wei
authors.forename: Bin
authors.initials: B
authors.lastname: Du
authors.forename: He
authors.initials: H
authors.lastname: Li
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D017886:Durapatite / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000379:methods*; D005295:Ferrocyanides; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007118:Immunoassay / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D000509:alpha-Fetoproteins / Q000032:analysis*
chemical_list: D005295:Ferrocyanides; D000509:alpha-Fetoproteins; D017886:Durapatite; C000170:ferric ferrocyanide