title: Nanogold-functionalized g-C3N4 nanohybrids for sensitive impedimetric immunoassay of prostate-specific antigen using enzymatic biocatalytic precipitation.
abstract: This work reports on a new impedimetric immunosensing strategy for sensitive detection of prostate-specific antigen (PSA) in biological fluids. The assay was carried out on monoclonal anti-PSA capture antibody-modified glassy carbon electrode with a sandwich-type detection format. Gold nanoparticles-decorated g-C3N4 nanosheets (AuNP/g-C3N4), synthesized by the wet-chemistry method, were utilized for the labeling of polyclonal anti-PSA detection antibody and horseradish peroxidase (HRP). Upon target PSA introduction, the sandwiched immunocomplex could be formed between capture antibody and detection antibody. Followed by the AuNP/g-C3N4, the labeled HRP could catalyze 4-choloro-1-naphthol into benzo-4-chlorohexadienone. The as-generated insoluble product was coated on the electrode surface, thus increasing the Faradaic impedance of Fe(CN)6(4-/3)(-) indicator between the solution and the base electrode. Under the optimal conditions, the impedance increased with the increasing target PSA in the sample, and exhibited a wide linear range from 10pgmL(-1) and 30ngmL(-1) with a detection limit of 5.2pgmL(-1). A repeatability and intermediate precision of <14% was accomplished. The specificity and method accuracy in comparison with commercial PSA ELISA kit for analysis of human serum specimens were relatively satisfactory.
authors.affiliation: Department of Urology, Jinling Hospital, Medical School of Nanjing University, Nanjing University, Nanjing, Jiangsu Province 210002, PR China.
authors.forename: Li-Li
authors.initials: LL
authors.lastname: Ding
authors.affiliation: Department of Urology, Jinling Hospital, Medical School of Nanjing University, Nanjing University, Nanjing, Jiangsu Province 210002, PR China.
authors.forename: Jing-Ping
authors.initials: JP
authors.lastname: Ge
authors.affiliation: Department of Urology, Jinling Hospital, Medical School of Nanjing University, Nanjing University, Nanjing, Jiangsu Province 210002, PR China.
authors.forename: Wen-Quan
authors.initials: WQ
authors.lastname: Zhou
authors.affiliation: Department of Urology, Jinling Hospital, Medical School of Nanjing University, Nanjing University, Nanjing, Jiangsu Province 210002, PR China.
authors.forename: Jian-Ping
authors.initials: JP
authors.lastname: Gao
authors.affiliation: Department of Urology, Jinling Hospital, Medical School of Nanjing University, Nanjing University, Nanjing, Jiangsu Province 210002, PR China. Electronic address: zhengyuzhang16@yeah.net.
authors.forename: Zheng-Yu
authors.initials: ZY
authors.lastname: Zhang
authors.affiliation: Department of Dermatology, Southwest Hospital, The Third Military Medical University, Gaotanyan Street, Chongqing 400038, PR China. Electronic address: doctorxya@163.com.
authors.forename: Ya
authors.initials: Y
authors.lastname: Xiong
mesh_terms: D000906:Antibodies / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods; D017097:Electric Impedance; D055664:Electrochemical Techniques / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry; D006735:Horseradish Peroxidase / Q000737:chemistry; D006801:Humans; D007118:Immunoassay / Q000379:methods; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D053761:Nanocomposites / Q000737:chemistry / Q000648:ultrastructure; D009570:Nitriles / Q000737:chemistry*; D017430:Prostate-Specific Antigen / Q000097:blood*
chemical_list: D000906:Antibodies; D009570:Nitriles; C011206:cyanogen; D006046:Gold; D006108:Graphite; D006735:Horseradish Peroxidase; D017430:Prostate-Specific Antigen
keywords: Electrochemical immunosensor; Enzymatic biocatalytic precipitation; Nanogold-decorated g-C(3)N(4) nanosheets; Prostate-specific antigen