title: Multiplexed electrochemical immunoassay using streptavidin/nanogold/carbon nanohorn as a signal tag to induce silver deposition.
abstract: An ultrasensitive multiplexed immunoassay method was developed by using streptavidin/nanogold/carbon nanohorn (SA/Au/CNH) as a novel signal tag to induce silver enhancement for signal amplification. The Au/CNH was prepared by in situ growth of nanogold on carboxylated CNH and functionalized with streptavidin. The SA/Au/CNH showed well dispersibility in physiological buffer and could sever as a common tracing tag to recognize biotinylated signal antibody. The immunosensor array was prepared on disposable screen-printed electrodes. Through sandwich-type immunoreaction and biotin-streptavidin affinity reaction, the SA/Au/CNH tag was captured on the immunoconjugates to induce silver deposition and amplify the electrochemical stripping signals. Using α-fetoprotein and carcinoembryonic antigen as model analytes, the proposed method showed wide linear ranges with the detection limits down to 0.024 pg mL(-1) and 0.032 pg mL(-1), respectively, and eliminated completely signal cross-talk between adjacent immunosensors. It provided a convenient, high-efficient and ultrasensitive electrochemical detection route for biological analytes, showing great potential in clinical application.
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, Department of Chemistry, Nanjing University, Nanjing 210093, PR China; School of Environmental Science and Public Health, Wenzhou Medical College, Wenzhou 325035, PR China.
authors.forename: Changrong
authors.initials: C
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, Department of Chemistry, Nanjing University, Nanjing 210093, PR China.
authors.forename: Jie
authors.initials: J
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, Department of Chemistry, Nanjing University, Nanjing 210093, PR China. Electronic address: hxju@nju.edu.cn.
authors.forename: Huangxian
authors.initials: H
authors.lastname: Ju
authors.affiliation: Jiangsu Institute of Cancer Prevention and Cure, Nanjing 210009, PR China. Electronic address: yanfeng2007@sohu.com.
authors.forename: Feng
authors.initials: F
authors.lastname: Yan
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry; D015374:Biosensing Techniques / Q000295:instrumentation; D019921:Biotinylation; D002272:Carcinoembryonic Antigen / Q000097:blood*; D055664:Electrochemical Techniques / Q000295:instrumentation; D004867:Equipment Design; D006046:Gold / Q000737:chemistry*; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D057230:Limit of Detection; D049329:Nanostructures / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D019809:Streptavidin / Q000737:chemistry*; D000509:alpha-Fetoproteins / Q000032:analysis*
chemical_list: D055910:Antibodies, Immobilized; D002272:Carcinoembryonic Antigen; D000509:alpha-Fetoproteins; D012834:Silver; D006046:Gold; D019809:Streptavidin
keywords: Carbon nanohorn; Electrochemical sensor; Immunosensor; Multiplexed immunoassay; Signal amplification; Silver enhancement