title: Magnetic colorimetric immunoassay for human interleukin-6 based on the oxidase activity of ceria spheres.
abstract: A novel magnetic colorimetric immunoassay strategy was designed for sensitive detection of human interleukin-6 (IL-6) using ceria spheres as labels. Ceria spheres showed excellent oxidase activity, which can directly catalyze the oxidation of substrate o-phenylenediamine (OPD) to a stable yellow product, 2,3-diaminophenazine (oxOPD). The absorbance of oxOPD was recorded to reflect the level of IL-6. The relatively mild conditions made the immunoassay strategy more robust, reliable, and easy. A linear relationship between absorbance intensity and the logarithm of IL-6 concentrations was obtained in the range of 0.0001-10 ng mL(-1) with a detection limit of 0.04 pg mL(-1) (S/N = 3). The colorimetric immunoassay exhibited high sensitivity and specificity for the detection of IL-6. This immunoassay has been successfully applied in the detection of IL-6 in serum samples and can be readily extended toward the on-site monitoring of cancer biomarkers in serum samples.
authors.affiliation: School of Chemistry and Chemical Engineering, Ningxia University, Yinchuan, 750021, People's Republic of China.
authors.forename: Juan
authors.initials: J
authors.lastname: Peng
authors.affiliation: School of Chemistry and Chemical Engineering, Ningxia University, Yinchuan, 750021, People's Republic of China.
authors.forename: Jufang
authors.initials: J
authors.lastname: Guan
authors.affiliation: Department of Chemistry, Ningxia Medical University, Yinchuan 750004, People's Republic of China.
authors.forename: Huiqin
authors.initials: H
authors.lastname: Yao
authors.affiliation: School of Chemistry and Chemical Engineering, Ningxia University, Yinchuan, 750021, People's Republic of China. Electronic address: jin_xy@nxu.edu.cn.
authors.forename: Xiaoyong
authors.initials: X
authors.lastname: Jin
mesh_terms: D000906:Antibodies / Q000737:chemistry / Q000276:immunology; D002563:Cerium / Q000737:chemistry* / Q000378:metabolism; D003124:Colorimetry; D052203:Ferrosoferric Oxide / Q000737:chemistry; D006801:Humans; D007118:Immunoassay; D015850:Interleukin-6 / Q000097:blood* / Q000737:chemistry / Q000276:immunology; D057230:Limit of Detection; D008280:Magnetics; D058185:Magnetite Nanoparticles / Q000737:chemistry; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000378:metabolism; D010655:Phenylenediamines / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000906:Antibodies; D015850:Interleukin-6; D058185:Magnetite Nanoparticles; D010655:Phenylenediamines; D002563:Cerium; C030583:ceric oxide; D010088:Oxidoreductases; D052203:Ferrosoferric Oxide
keywords: Catalytic property; Ceria sphere; Colorimetric immunoassay; Human Interleukin-6