Dual signal amplification of glucose oxidase-functionalized nanocomposites as a trace label for ultrasensitive simultaneous multiplexed electrochemical detection of tumor markers.
A novel tracer, glucose oxidase-functionalized nanocomposite, was designed to label the signal antibodies for ultrasensitive multiplexed measurement of tumor markers using a disposable immunosensor array. The immunosensor array was constructed by coating layer-by-layer colloidal Prussian blue (PB), gold nanoparticles, and capture antibodies on screen-printed carbon electrodes. The preparation of glucose oxidase-functionalized nanocomposites and the labeling of antibody were performed by one-pot assembly of glucose oxidase and antibody on gold nanoparticles attached carbon nanotubes. The PB immobilized on immunosensor surface acted as a mediator to catalyze the reduction of H2O2 produced in the enzymatic cycle. Both the high-content glucose oxidase and carbon nanotubes in the tracer amplified the detectable signal for the sandwich-type immunoassay. Using carcinoembryonic antigen and alpha-fetoprotein as model analytes, the simultaneous multiplexed immunoassay method using the immunosensor array and the designed tracer showed linear ranges of 3 orders of magnitude with the detection limits down to 1.4 and 2.2 pg/mL, respectively. The assay results of serum samples with the proposed method were in an acceptable agreement with the reference values. The dual signal amplification of glucose oxidase-functionalized nanocomposites provided a promising ultrasensitive simultaneous multiplexed immunoassay approach for clinical applications.
Lai
Guosong
G
Key Laboratory of Analytical Chemistry for Life Science (Ministry of Education of China), Department of Chemistry, Nanjing University, Nanjing 210093, P.R. China.
Yan
Feng
F
Ju
Huangxian
H
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000032:analysis* / Q000276:immunology; D002417:Cattle; D003429:Cross Reactions; D004563:Electrochemistry; D004579:Electron Transport; D005295:Ferrocyanides / Q000737:chemistry; D005949:Glucose Oxidase / Q000737:chemistry / Q000378:metabolism*; D006046:Gold / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D051379:Mice; D053761:Nanocomposites / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry; D013194:Staining and Labeling; D013997:Time Factors
D000911:Antibodies, Monoclonal; D014408:Biomarkers, Tumor; D005295:Ferrocyanides; D037742:Nanotubes, Carbon; D006046:Gold; D005949:Glucose Oxidase; C000170:ferric ferrocyanide