title: An "in-electrode"-type immunosensing strategy for the detection of squamous cell carcinoma antigen based on electrochemiluminescent AuNPs/g-C3N4 nanocomposites.
abstract: A novel "in-electrode"-type electrochemiluminescence (ECL) immunosensor for the sensitive detection of squamous cell carcinoma antigen (SCCA) was constructed using magnetic graphene oxide (nanoFe3O4@GO) and Au nanoparticles/graphitic-phase carbon nitride (AuNPs/g-C3N4). The capture probe was prepared by immobilizing the primary antibody of SCCA (Ab1) on the nanoFe3O4@GO, while the AuNPs/g-C3N4 nanocomposites labelled the secondary antibody of SCCA (Ab2), which acted as a signal tag. The recognition scaffold was the following: the capture probe was immobilized onto the magnetic electrode surface that caught the target SCCA and finally allowed the immobilization of the signal tag via the interaction between antigen and antibody. Importantly, a high ECL signal could be obtained due to the unique immunocomplex, which ensured all of the g-C3N4 on the outmost plane were directly fixed onto the electrode surface and became part of the electrode surface. This resulted in an enhanced efficiency of the g-C3N4 for electrochemical luminescence, thus extending the outer Helmholtz plane (OHP) of the proposed electrode and leading to high sensitivity. Taking advantage of both nanoFe3O4@GO and AuNPs/g-C3N4, the ECL intensity was found to increase logarithmically with SCCA concentration in a wide linear range from 0.001 to 10ng/mL and with a detection limit of 0.4pg/mL. The proposed "in-electrode"-type ECL immunosensor was used to analyse SCCA in human serum, and satisfactory recoveries were obtained, indicating that the proposed method was promising for practical applications in the clinical diagnosis of SCCA.
authors: Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo, 315211, PR China.
authors: Lin
authors: L
authors: Wu
authors: Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo, 315211, PR China.
authors: Yufang
authors: Y
authors: Hu
authors: Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo, 315211, PR China.
authors: Yuhong
authors: Y
authors: Sha
authors: Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo, 315211, PR China.
authors: Wenrou
authors: W
authors: Li
authors: Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo, 315211, PR China.
authors: Tiantian
authors: T
authors: Yan
authors: Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo, 315211, PR China.
authors: Sui
authors: S
authors: Wang
authors: Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo, 315211, PR China.
authors: Xing
authors: X
authors: Li
authors: Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo, 315211, PR China. Electronic address: guozhiyong@nbu.edu.cn.
authors: Zhiyong
authors: Z
authors: Guo
authors: School of Marine Sciences, Ningbo University, Ningbo, 315211, PR China.
authors: Jun
authors: J
authors: Zhou
authors: School of Marine Sciences, Ningbo University, Ningbo, 315211, PR China.
authors: Xiurong
authors: X
authors: Su
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry / Q000276:immunology; D000951:Antigens, Neoplasm / Q000097:blood* / Q000737:chemistry / Q000276:immunology; D015374:Biosensing Techniques; D055664:Electrochemical Techniques; D004566:Electrodes; D052203:Ferrosoferric Oxide / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D064347:Microscopy, Electrochemical, Scanning; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D009570:Nitriles / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry; D015843:Serpins / Q000097:blood* / Q000737:chemistry / Q000276:immunology
chemical_list: D055910:Antibodies, Immobilized; D000951:Antigens, Neoplasm; D009570:Nitriles; D010087:Oxides; D015843:Serpins; C051072:squamous cell carcinoma-related antigen; C011206:cyanogen; D006046:Gold; D006108:Graphite; D052203:Ferrosoferric Oxide
keywords: Electrochemiluminescence immunosensor; Graphene oxide; Graphitic-phase carbon nitride; Outer Helmholtz plane; Squamous cell carcinoma antigen; “In-electrode”-type immunoassay