Glucose oxidase-doped magnetic silica nanostrutures as labels for localized signal amplification of electrochemical immunosensors.
Herein, we report a novel glucose oxidase (GOD)-doped magnetic silica nanostructure and its possible application in the clinical immunoassays. The doped nanostructures were initially synthesized using the reverse micelle method, and ferritin antibodies (anti-Ft) were then labeled to the surface of the nanostructures, which were employed as signal antibodies for ultrasensitive detection of ferritin (Ft) in the sandwich-type electrochemical enzyme immunoassays. The doped nanostructures were characterized using transmission electron microscopy (TEM), UV-vis absorption spectrometry and vibrating sample magnetometer (VSM). The advantages of the doped nanostructures as labels were investigated in comparison with the conventional label method. Under the optimal conditions, the nanostructures-based immunoassay toward ferritin standards displays a wide dynamic range from 0.1 to 400 ng mL(-1) with a low detection limit of 10 pg mL(-1) ferritin (at 3sigma), which is three-fold higher in the sensitivity than that of directly using GOD-labeled antibodies. The assay results for clinical serum samples with the developed method received in excellent accordance with results obtained from the referenced standard enzyme-linked immunosorbent assay (ELISA) method.
Ren
Jingjing
J
Key Laboratory of Analysis and Detection for Food Safety (Ministry of Education), Department of Chemistry, Fuzhou University, Fuzhou 350108, China.
Tang
Dianping
D
Su
Biling
B
Tang
Juan
J
Chen
Guonan
G
D000906:Antibodies / Q000276:immunology; D015374:Biosensing Techniques / Q000379:methods*; D055664:Electrochemical Techniques / Q000379:methods; D005293:Ferritins / Q000032:analysis; D005949:Glucose Oxidase / Q000737:chemistry* / Q000378:metabolism; D007118:Immunoassay / Q000379:methods; D008280:Magnetics; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D012822:Silicon Dioxide / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
D000906:Antibodies; D012822:Silicon Dioxide; D005293:Ferritins; D005949:Glucose Oxidase