title: Fabrication of highly catalytic silver nanoclusters/graphene oxide nanocomposite as nanotag for sensitive electrochemical immunoassay.
abstract: Silver nanoclusters and graphene oxide nanocomposite (AgNCs/GRO) is synthesized and functionalized with detection antibody for highly sensitive electrochemical sensing of carcinoembryonic antigen (CEA), a model tumor marker involved in many cancers. AgNCs with large surface area and abundant amount of low-coordinated sites are synthesized with DNA as template and exhibit high catalytic activity towards the electrochemical reduction of H2O2. GRO is employed to assemble with AgNCs because it has large specific surface area, super electronic conductivity and strong π-π stacking interaction with the hydrophobic bases of DNA, which can further improve the catalytic ability of the AgNCs. Using AgNCs/GRO as signal amplification tag, an enzyme-free electrochemical immunosensing protocol is designed for the highly sensitive detection of CEA on the capture antibody functionalized immunosensing interface. Under optimal conditions, the designed immunosensor exhibits a wide linear range from 0.1 pg mL(-1) to 100 ng mL(-1) and a low limit of detection of 0.037 pg mL(-1). Practical sample analysis reveals the sensor has good accuracy and reproducibility, indicating the great application prospective of the AgNCs/GRO in fabricating highly sensitive immunosensors, which can be extended to the detection of various kinds of low abundance disease related proteins.
authors.affiliation: School of Chemistry, Dalian University of Technology, Dalian 116023, PR China.
authors.forename: Jiamian
authors.initials: J
authors.lastname: Wang
authors.affiliation: School of Chemistry, Dalian University of Technology, Dalian 116023, PR China.
authors.forename: Xiuyun
authors.initials: X
authors.lastname: Wang
authors.affiliation: School of Chemistry, Dalian University of Technology, Dalian 116023, PR China. Electronic address: wushuo@dlut.edu.cn.
authors.forename: Shuo
authors.initials: S
authors.lastname: Wu
authors.affiliation: School of Chemistry, Dalian University of Technology, Dalian 116023, PR China.
authors.forename: Jie
authors.initials: J
authors.lastname: Song
authors.affiliation: School of Chemistry, Dalian University of Technology, Dalian 116023, PR China.
authors.forename: Yanqiu
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: School of Chemistry, Dalian University of Technology, Dalian 116023, PR China.
authors.forename: Yanqiu
authors.initials: Y
authors.lastname: Ge
authors.affiliation: School of Chemistry, Dalian University of Technology, Dalian 116023, PR China.
authors.forename: Changgong
authors.initials: C
authors.lastname: Meng
mesh_terms: D002384:Catalysis; D055664:Electrochemical Techniques / Q000379:methods*; D006108:Graphite / Q000737:chemistry*; D007118:Immunoassay / Q000379:methods*; D057230:Limit of Detection; D046529:Microscopy, Electron, Transmission; D049329:Nanostructures; D010087:Oxides / Q000737:chemistry; D012834:Silver / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D010087:Oxides; D012834:Silver; D006108:Graphite
keywords: Electrochemical immunosensors; Enzyme-free; Gold nanoparticle and chitosan matrix; Signal amplification; Silver nanoclusters and graphene oxide nanocomposites