title: An ultrasensitive electrochemical immunosensor for apolipoprotein E4 based on fractal nanostructures and enzyme amplification.
abstract: Human apolipoprotein E4 (APOE4) is a major risk factor for Alzheimer's disease (AD) and can greatly increase the morbidity. In this work, an ultrasensitive sandwich-type electrochemical immunosensor for the quantitative detection of APOE4 was designed based on fractal gold (FracAu) nanostructures and enzyme amplification. The FracAu nanostructures were directly electrodeposited by hydrogen tetrachloroaurate (HAuCl4) on polyelectrolytes modified indium tin oxide (ITO) electrode. The sensing performances of the modified interface were investigated by cyclic voltammetry (CV). After functionalization with HRP-labeled APOE4 antibody, the human APOE4 could be detected quantitatively by current response. The current response has a linear relationship with the logarithm of human APOE4 concentrations in a range from 1.0 to 10,000.0 ng/mL, with a detection limit of 0.3 ng/mL. The fabricated APOE4 electrochemical immunosensor exhibits strong specificity, high sensitivity, low detection limit and wide linear range. The detection of human APOE4 provides a strong support for the prevention of AD and early-stage warning for those susceptible populations.
authors.affiliation: Research Centre for Bioengineering and Sensing Technology, University of Science & Technology Beijing, Beijing 100083, PR China; School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, PR China.
authors.forename: Yibiao
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Research Centre for Bioengineering and Sensing Technology, University of Science & Technology Beijing, Beijing 100083, PR China; School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, PR China. Electronic address: xuliping@ustb.edu.cn.
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Xu
authors.affiliation: Research Centre for Bioengineering and Sensing Technology, University of Science & Technology Beijing, Beijing 100083, PR China; School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, PR China.
authors.forename: Shuqi
authors.initials: S
authors.lastname: Wang
authors.affiliation: Research Centre for Bioengineering and Sensing Technology, University of Science & Technology Beijing, Beijing 100083, PR China; School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, PR China.
authors.forename: Weizhao
authors.initials: W
authors.lastname: Yang
authors.affiliation: Research Centre for Bioengineering and Sensing Technology, University of Science & Technology Beijing, Beijing 100083, PR China; School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, PR China.
authors.forename: Yongqiang
authors.initials: Y
authors.lastname: Wen
authors.affiliation: Research Centre for Bioengineering and Sensing Technology, University of Science & Technology Beijing, Beijing 100083, PR China; School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083, PR China. Electronic address: zhangxueji@ustb.edu.cn.
authors.forename: Xueji
authors.initials: X
authors.lastname: Zhang
mesh_terms: D053327:Apolipoprotein E4 / Q000032:analysis* / Q000737:chemistry / Q000276:immunology; D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D017709:Fractals; D006046:Gold / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000737:chemistry*; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008832:Microchemistry / Q000295:instrumentation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D053327:Apolipoprotein E4; D006046:Gold; D006735:Horseradish Peroxidase
keywords: APOE4; Alzheimer's disease; Fractal Au nanostructure; Immunosensor