title: Silver deposition directed by self-assembled gold nanorods for amplified electrochemical immunoassay.
abstract: A novel electrochemical immunoassay was developed based on the signal amplification strategy of silver deposition directed by gold nanorods (AuNRs), which was in-situ assembled on the sandwich immunocomplex. The superstructure formed by the self-assembly of AuNRs provided abundant active sites for the nucleation of silver nanoparticles. In this pathway, the stripping current of silver was greatly enhanced. Using human immunoglobulin G (HIgG) as a model analyte, the ultrasensitive immunoassay showed a wide linear range of six orders of magnitude from 0.1 fg mL(-1) to 100 pg mL(-1), with the low detection limit down to 0.08 fg mL(-1). The practicality of this electrochemical immunoassay for detection of HIgG in serum was validated with the average recovery of 93.9%. In addition, this enzyme-free immunoassay also has the advantages of acceptable reproducibility and specificity, and thus this immunosensing protocol can be extended to the detection of other low-abundant protein biomarkers.
authors.affiliation: Ministry of Education Key Laboratory of Synthetic and Natural Functional Molecular Chemistry, College of Chemistry and Materials Science, Northwest University, Xi'an 710069, PR China; Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry, Northwest University, Xi'an 710069, PR China. Electronic address: zhanghf@nwu.edu.cn.
authors.forename: Hongfang
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Ministry of Education Key Laboratory of Synthetic and Natural Functional Molecular Chemistry, College of Chemistry and Materials Science, Northwest University, Xi'an 710069, PR China.
authors.forename: Danlei
authors.initials: D
authors.lastname: Ning
authors.affiliation: Ministry of Education Key Laboratory of Synthetic and Natural Functional Molecular Chemistry, College of Chemistry and Materials Science, Northwest University, Xi'an 710069, PR China.
authors.forename: Lina
authors.initials: L
authors.lastname: Ma
authors.affiliation: Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry, Northwest University, Xi'an 710069, PR China. Electronic address: zhengjb@nwu.edu.cn.
authors.forename: Jianbin
authors.initials: J
authors.lastname: Zheng
mesh_terms: D000818:Animals; D055664:Electrochemical Techniques / Q000379:methods*; D006046:Gold / Q000737:chemistry*; D007118:Immunoassay / Q000379:methods*; D051379:Mice; D043942:Nanotubes; D012834:Silver / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D012834:Silver; D006046:Gold
keywords: Gold nanorod; Human IgG; Immunosensor; Signal amplification; Silver deposition