title: Prussian blue-gold nanoparticles-ionic liquid functionalized reduced graphene oxide nanocomposite as label for ultrasensitive electrochemical immunoassay of alpha-fetoprotein.
abstract: In this work, poly(diallyldimethylammonium chloride) (PDDA) protected Prussian blue/gold nanoparticles/ionic liquid functionalized reduced graphene oxide (IL-rGO-Au-PDDA-PB) nanocomposite was fabricated. The resulting nanocomposite exhibited high biocompatibility, conductivity and catalytic activity. To assess the performance of the nanocomposite, a sensitive sandwich-type immunosensor was constructed for detecting alpha-fetoprotein (AFP). Greatly enhanced sensitivity for this immunosensor was based on triple signal amplification strategies. Firstly, IL-rGO modified electrode was used as biosensor platform to capture a large amount of antibody due to its increased surface area, thus amplifying the detection response. Secondly, a large number of Au-PDDA-PB was conjugated on the surface of IL-rGO, which meant the enrichment of the signal and the more immobilization of label antibody. Finally, the catalytic reaction between H2O2 and the IL-rGO-Au-PDDA-PB nanocomposite further enhanced the signal response. The signals increased linearly with AFP concentrations in the range of 0.01-100 ng mL(-1). The detection limit for AFP was 4.6 pg mL(-1). The immunosensor showed high sensitivity, excellent selectivity and good stability. Moreover, the immunosensor was applied to the analysis of AFP in serum sample with satisfactory result.
authors.affiliation: Department of Chemistry, Capital Normal University, Beijing, 100048, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Gao
authors.affiliation: Department of Chemistry, Capital Normal University, Beijing, 100048, China.
authors.forename: Na
authors.initials: N
authors.lastname: Liu
authors.affiliation: Department of Chemistry, Capital Normal University, Beijing, 100048, China. Electronic address: mazhanfang@cnu.edu.cn.
authors.forename: Zhanfang
authors.initials: Z
authors.lastname: Ma
mesh_terms: D000906:Antibodies / Q000737:chemistry / Q000276:immunology; D015374:Biosensing Techniques; D002384:Catalysis; D055664:Electrochemical Techniques; D004566:Electrodes; D005295:Ferrocyanides / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry; D007118:Immunoassay; D052578:Ionic Liquids / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry; D011095:Polyethylenes / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D000509:alpha-Fetoproteins / Q000032:analysis* / Q000276:immunology
chemical_list: D000906:Antibodies; D005295:Ferrocyanides; D052578:Ionic Liquids; D010087:Oxides; D011095:Polyethylenes; D000644:Quaternary Ammonium Compounds; D000509:alpha-Fetoproteins; C041004:poly-N,N-dimethyl-N,N-diallylammonium chloride; D006046:Gold; D006108:Graphite; D006861:Hydrogen Peroxide; C000170:ferric ferrocyanide
keywords: Alpha-fetoprotein; Electrochemical immunosensor; Ionic liquid functionalized reduced graphene oxide; Prussian blue