Ultrasensitive electrochemical immunosensor based on horseradish peroxidase (HRP)-loaded silica-poly(acrylic acid) brushes for protein biomarker detection.
We report an ultrasensitive electrochemical immunosensor designed for the detection of protein biomarkers using horseradish peroxidase (HRP)-loaded silica-poly(acrylic acid) brushes (SiO2-SPAABs) as labels. HRP could be efficiently and stably accommodated in the three-dimensional architecture of the SiO2-SPAABs and the SiO2-SPAABs-HRP exhibited high catalytic performance towards o-phenylenediamine (OPD) oxidation in the presence of H2O2, which resulted in significant differential pulse voltammetric (DPV) response change and color change. Using human IgG (HIgG) as a model analyte, a sandwich-type immunosensor was constructed. In particular, graphene oxide (GO) and SiO2-SPAABs-HRP were used to immobilize capture antibody (Ab1) and bind a layer of detection antibody (Ab2), respectively. The current biosensor exhibited a good linear response of HIgG from 100pg/mL to 100μg/mL with a detection limit of 50pg/mL (S/N=5). The sensitivity was 6.70-fold higher than the conventional enzyme-linked immunosorbent assays. The immunosensor results were validated through the detection of HIgG in serum samples.
The Key Laboratory of Life-Organic Analysis, College of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, Shandong 273165, PR China.
Yan
Y
Zhao
Leadernano Tech. L.L.C., Jining, Shandong 272000, PR China.
Yiqun
Y
Zheng
The Key Laboratory of Life-Organic Analysis, College of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, Shandong 273165, PR China.
Rongmei
R
Kong
The Key Laboratory of Life-Organic Analysis, College of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, Shandong 273165, PR China.
Lian
L
Xia
The Key Laboratory of Life-Organic Analysis, College of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, Shandong 273165, PR China. Electronic address: fengliquhn@hotmail.com.
Fengli
F
Qu
D000180:Acrylic Resins / Q000737:chemistry; D000906:Antibodies / Q000737:chemistry / Q000276:immunology; D015415:Biomarkers / Q000097:blood* / Q000737:chemistry; D015374:Biosensing Techniques; D055664:Electrochemical Techniques; D006046:Gold; D006108:Graphite / Q000737:chemistry; D006735:Horseradish Peroxidase / Q000737:chemistry; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D007118:Immunoassay; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology / Q000302:isolation & purification*; D010655:Phenylenediamines / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry
D000180:Acrylic Resins; D000906:Antibodies; D015415:Biomarkers; D007074:Immunoglobulin G; D010655:Phenylenediamines; C006903:carbopol 940; D006046:Gold; D012822:Silicon Dioxide; D006108:Graphite; C034193:1,2-diaminobenzene; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase
Electrochemical immunoassay; Enzyme catalysis; Horseradish peroxidase; Protein biomarker; Silica-poly(acrylic acid) brushes