title: Sandwich-type electrochemical immunosensor for the detection of AFP based on Pd octahedral and APTES-M-CeO₂-GS as signal labels.
abstract: In the present work, an ultrasensitive sandwich-type electrochemical immunosensor based on a novel signal amplification strategy was designed for quantitative detection of alpha fetoprotein (AFP). Au nanoparticles with biocompatibility were electrodeposited on the surface of glassy carbon electrode (GCE) which can effectively capture and immobilize primary anti-AFP (Ab1) to significantly amplify the electrochemical signal. Graphene Oxide and CeO2 mesoporous nanocomposite functionalized by the 3-aminopropyltriethoxysilane supported Pd octahedral nanoparticles (Pd/APTES-M-CeO2-GS) were utilized as labels of detection anti-AFP (Ab2). Pd octahedral nanoparticles presented good catalytic activity towards the reduction of H2O2. Due to the large specific surface area and good adsorption properties of APTES-CeO2-GS nanocomposite, large amount of Pd octahedral nanoparticles could be immobilized, which could amplify the electrochemical signal and improve the sensitivity of the immunosensor. Under optimal conditions, the immunosensor exhibited wide linear range from 0.1 pg/mL to 50 ng/mL with a low detection limit of 0.033 pg/mL (S/N=3) for AFP detection. In addition, high sensitivity, excellent selectivity, good reproducibility and stability were obtained for the immunosensor, which has a promising application for quantitative detection of other tumor markers in clinical diagnosis.
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Yicheng
authors.initials: Y
authors.lastname: Wei
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Tao
authors.initials: T
authors.lastname: Yan
authors.affiliation: 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: mahongmin2002@126.com.
authors.forename: Hongmin
authors.initials: H
authors.lastname: Ma
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Wei
mesh_terms: D002563:Cerium / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000379:methods*; D006108:Graphite / Q000737:chemistry; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D007118:Immunoassay / Q000379:methods*; D057230:Limit of Detection; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010087:Oxides / Q000737:chemistry; D010165:Palladium / Q000737:chemistry*; D011437:Propylamines; D015203:Reproducibility of Results; D012821:Silanes / Q000737:chemistry*; D000509:alpha-Fetoproteins / Q000032:analysis*
chemical_list: D010087:Oxides; D011437:Propylamines; D012821:Silanes; D000509:alpha-Fetoproteins; D002563:Cerium; D010165:Palladium; C030583:ceric oxide; D006108:Graphite; D006861:Hydrogen Peroxide; C477625:amino-propyl-triethoxysilane
keywords: Alpha fetoprotein; CeO(2) mesoporous nanoparticles; Pd octahedral; Sandwich-type immunosensor