Chimie médicale

Surface Modification of Superparamagnetic Magnetite Nanoparticles and Its Application for Detection of Anti-CEA Using Electrochemiluminescent Immunosensor

Abstract

Guixin Huang, Biyang Deng, Qing Xi, Chunyao Tao and Li Ye

A highly sensitive sandwich-type ECLIA technique using ruthenium complexes as labels was reported. Superparamagnetic nanoparticles were synthesized with a diameter of 12 nm through a coprecipitation method and used as the matrix solid-phase. Then, the ECL targets of Ru(bpy)2(dcbpy)NHS were successfully synthesized and labeled on the IgG. Furthermore, on the formation of an antibody-antigen immunocomplex, biotin-streptavidin system and on the basis of the strong and stable ECL signal, we designed a novel multiple signal amplification of sandwichtype ECLIA for sensitive detection of carcinoembryonic antigen (CEA) antibody. The calibration curve was linear in the range of 1.0–780 ng mL–1 with a detection limit of 0.28 ng mL–1 (σ = 3) and relative standard deviation of 3.9% (n = 6). The results indicated that the new sandwich-type ECLIA provide several advantages, such as high sensitivity, good selectivity, and wide linear range. This technique can be used in detection of anti-CEA as well as of other tumor markers.