title: Sandwich-type electrochemical immunosensor using dumbbell-like nanoparticles for the determination of gastric cancer biomarker CA72-4.
abstract: A novel and sensitive nonenzymatic sandwich-type electrochemical immunosensor for the detection of gastric cancer biomarker CA72-4 was fabricated using dumbbell-like PtPd-Fe3O4 nanoparticles (NPs) as a novel kind of label. The signal amplification strategy, using the synergetic effect present in PtPd-Fe3O4 to increase the reduction ability of the NPs toward H2O2, improved the sensitivity of the immunosensor. The immunosensor was constructed by modifying glassy carbon electrode with reduced graphene oxide-tetraethylene pentamine (rGO-TEPA) for effective immobilization of primary anti-CA72-4 antibody (Ab1). Secondary anti-CA72-4 antibody (Ab2) was adsorbed onto the PtPd-Fe3O4 NPs. The proposed immunosensor displayed a wide linear range (0.001-10 U/mL) with the low detection limit (0.0003 U/mL). The immunosensor was evaluated for serum samples, receiving satisfactory results. Therefore, the immunosensor possesses excellent clinical value in cancer screening as well as convenient point-of-care diagnostics.
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Wu
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
authors.forename: Zhankui
authors.initials: Z
authors.lastname: Guo
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
authors.forename: Yixin
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
authors.forename: Aiping
authors.initials: A
authors.lastname: Guo
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
authors.forename: Wanruo
authors.initials: W
authors.lastname: Lou
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
authors.forename: Dawei
authors.initials: D
authors.lastname: Fan
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China. Electronic address: sdjndxwq@163.com.
authors.forename: Qin
authors.initials: Q
authors.lastname: Wei
mesh_terms: D055910:Antibodies, Immobilized; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000097:blood*; D014408:Biomarkers, Tumor / Q000097:blood*; D015374:Biosensing Techniques; D002244:Carbon / Q000737:chemistry; D055664:Electrochemical Techniques; D004566:Electrodes; D005029:Ethylenediamines / Q000737:chemistry; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D007118:Immunoassay; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D013274:Stomach Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000276:immunology
chemical_list: D055910:Antibodies, Immobilized; D015295:Antigens, Tumor-Associated, Carbohydrate; D014408:Biomarkers, Tumor; C083825:CA-72-4 antigen; D005029:Ethylenediamines; D002244:Carbon; D006861:Hydrogen Peroxide; C034269:tetraethylenepentamine
keywords: Gastric cancer biomarker CA72-4; Immunosensor; PtPd-Fe(3)O(4) nanoparticles; Reduced graphene oxide-tetraethylene pentamine (rGO-TEPA)