Electrochemical immunosensor for carcinoembryonic antigen based on antigen immobilization in gold nanoparticles modified chitosan membrane.
A disposable electrochemical immunosensor for carcinoembryonic antigen (CEA) was proposed based on the antigen immobilized in a colloidal gold nanoparticles modified chitosan membrane on the surface of an indium-tin oxide (ITO) electrode. The different membranes were characterized by scanning electron microscope and electrochemical methods. Based on a competitive immunoassay format, the immobilized antigen of the immunosensor was incubated with a horseradish peroxidase (HRP) labeled antibody and sample CEA antigen, and the formed immunoconjugate in the immunosensor was detected by an o-phenylenediamine-H(2)O(2)-HRP electrochemical system. Under the optimal experimental conditions, the electrocatalytic current decreased linearly with the competitive mechanism. CEA could be determined in the linear range from 2.0 to 20 ng/ml with a detection limit of 1.0 ng/ml. The prepared CEA immunosensor is not only economic due to the low-cost ITO electrode obtained from industrial mass production, but is also capable with good stability and reproducibility for batch fabrication.
Lin
Jiehua
J
College of Chemistry and Molecular Engineering, Qingdao University of Science & Technology, P.R. China.
Qu
Wei
W
Zhang
Shusheng
S
D002138:Calibration; D002272:Carcinoembryonic Antigen / Q000032:analysis* / Q000737:chemistry / Q000276:immunology; D048271:Chitosan / Q000737:chemistry*; D004563:Electrochemistry; D004566:Electrodes; D006046:Gold / Q000737:chemistry*; D007118:Immunoassay / Q000379:methods*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D013499:Surface Properties; D017971:Tin Compounds / Q000737:chemistry
D002272:Carcinoembryonic Antigen; D017971:Tin Compounds; C109984:indium tin oxide; D006046:Gold; D048271:Chitosan