title: An immune sandwich assay of carcinoembryonic antigen based on the joint use of upconversion phosphors and magnetic beads.
abstract: We herein report a sensitive and selective immunosensor for carcinoembryonic antigen (CEA) based on the joint use of upconversion phosphors (UCPs) and magnetic beads (MBs). UCPs as the signal probe were designed with a core-shell structure which provided a 40-fold enhancement of the luminescence intensity. Poly(acrylic acid) (PAA)-modified UCPs were covalently conjugated with the anti-CEA antibody (coating), and streptavidin functionalized magnetic beads were combined with another biotin-tagged anti-CEA antibody. With the assistance of a magnet, the as-formed immune sandwich in the presence of CEA can be readily separated from the assay matrix. The immunosensor showed a linear dynamic range for CEA within 0.05-20 ng mL(-1) in a buffered aqueous solution, and 0.1-20 ng mL(-1) in a human serum sample. The sensor was highly specific to CEA. Our results have suggested the potential application of the UCP-MB based immunoassay for CEA in clinical analysis.
authors.affiliation: Department of Chemical and Environmental Engineering, Hubei University of Nationalities, Enshi 445000, China.
authors.forename: Yaohua
authors.initials: Y
authors.lastname: Li
authors.forename: Zhengjun
authors.initials: Z
authors.lastname: Wu
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Liu
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D002021:Buffers; D002272:Carcinoembryonic Antigen / Q000032:analysis* / Q000097:blood / Q000737:chemistry; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D008163:Luminescent Measurements; D059346:Magnets / Q000737:chemistry*; D008863:Microspheres; D019301:Oleic Acid / Q000737:chemistry; D019809:Streptavidin / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; D002021:Buffers; D002272:Carcinoembryonic Antigen; D019301:Oleic Acid; C006903:carbopol 940; D019809:Streptavidin