title: In situ deposition of Prussian blue on mesoporous carbon nanosphere for sensitive electrochemical immunoassay.
abstract: A Prussian blue (PB) functionalized mesoporous carbon nanosphere (MCN) composite was prepared for loading signal antibody and high-content glucose oxidase (GOD) to obtain a new nanoprobe for sensitive electrochemical immunoassay. The MCN nanocarrier with an average diameter of 180 nm was synthesized by using mesoporous silica nanosphere as a hard template in combination with a hydrothermal carbonization method. This hydrophilic carbon nanomaterial provided an ideal platform for in situ deposition of high-content PB to form the MCN-PB nanocomposite. Based on the step-wise assembly of polyelectrolyte and gold nanoparticles (Au NPs) on the negative-charged nanocomposite, signal antibody and high-content GOD were loaded on this nanocarrier to obtain the nanoprobe. After a sandwich immunoreaction at an Au NPs-modified screen-printed carbon electrode based immunosensor, the nanoprobes were quantitatively captured on the electrode surface to produce sensitive electrochemical response with a PB-mediated GOD catalytic reaction for immunoassay. The high loading of PB and GOD on the nanoprobe greatly amplified the electrochemical signal, leading to the development of a new immunoassay method with high sensitivity. Using human immunoglobulin G as a model analyte, excellent analytical performance including a wide linear range from 0.01 to 100 ng/mL and a low detection limit down to 7.8 pg/mL was obtained. Additionally, the immunosensor showed high specificity, satisfactory stability and repeatability as well as acceptable reliability. The PB-mediated GOD electrochemical system well excluded the conventional interference from the dissolved oxygen. Thus this immunoassay method provides great potentials for practical applications.
authors.affiliation: Hubei Collaborative Innovation Center for Rare Metal Chemistry, Hubei Key Laboratory of Pollutant Analysis & Reuse Technology, Department of Chemistry, Hubei Normal University, Huangshi 435002, PR China; State Key Laboratory of Analytical Chemistry for Life Science, Department of Chemistry, Nanjing University, Nanjing 210093, PR China. Electronic address: gslai@hbnu.edu.cn.
authors.forename: Guosong
authors.initials: G
authors.lastname: Lai
authors.affiliation: Hubei Collaborative Innovation Center for Rare Metal Chemistry, Hubei Key Laboratory of Pollutant Analysis & Reuse Technology, Department of Chemistry, Hubei Normal University, Huangshi 435002, PR China.
authors.forename: Haili
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Hubei Collaborative Innovation Center for Rare Metal Chemistry, Hubei Key Laboratory of Pollutant Analysis & Reuse Technology, Department of Chemistry, Hubei Normal University, Huangshi 435002, PR China; Department of Chemistry and Biotechnology, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn VIC 3122, Australia. Electronic address: aiminyu@swin.edu.au.
authors.forename: Aimin
authors.initials: A
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, Department of Chemistry, Nanjing University, Nanjing 210093, PR China.
authors.forename: Huangxian
authors.initials: H
authors.lastname: Ju
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation; D002244:Carbon / Q000737:chemistry; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis; D003217:Conductometry / Q000295:instrumentation*; D004566:Electrodes; D004800:Enzymes, Immobilized / Q000737:chemistry; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005295:Ferrocyanides / Q000737:chemistry*; D005947:Glucose / Q000032:analysis* / Q000737:chemistry; D005949:Glucose Oxidase / Q000737:chemistry* / Q000276:immunology; D007118:Immunoassay / Q000295:instrumentation*; D058608:Nanopores / Q000648:ultrastructure; D054118:Nanospheres / Q000737:chemistry*; D016062:Porosity; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D020099:Coated Materials, Biocompatible; D004800:Enzymes, Immobilized; D005295:Ferrocyanides; D002244:Carbon; D005949:Glucose Oxidase; D005947:Glucose; C000170:ferric ferrocyanide
keywords: Biosensor; Carbon nanosphere; Electrochemical immunoassay; Prussian blue; Signal amplification