title: Determination of cortisol in human blood sera by a new Ag(III) complex-luminol chemiluminescent system.
abstract: A new chemiluminescence (CL) system based on the reaction of Ag(III) complex with luminol is, for the first time, reported in this work. Incorporated with a flow injection analyses (FIA), the new CL system has been applied for the determination of free cortisol in human sera. The system is based on the CL reaction of luminol with Ag(III) in alkaline solutions, while cortisol can dramatically enhance CL intensities. Under optimum conditions, CL intensities are proportional to concentration of cortisol in the range of 0.05-7.5 nM. The limit of detection is 2.0x10(-11) M (3sigma), with a relative standard deviation (n=11) of 1.9% for 3.5x10(-9) M cortisol. Eight human blood serum samples were all handled by solid-phase extraction (SPE) clean-up and enrichment before detection. This detection system is highly sensitive and convenient and may find wide applications. Based on the chemiluminescent spectra, a possible reaction mechanism is also suggested.
authors.affiliation: School of Public Health, Hebei Medical University, East Zhongshan Road 361, Shijiazhuang, Hebei Province 050017, People's Republic of China.
authors.forename: Hongmei
authors.initials: H
authors.lastname: Shi
authors.forename: Xiangdong
authors.initials: X
authors.lastname: Xu
authors.forename: Yuexin
authors.initials: Y
authors.lastname: Ding
authors.forename: Shipeng
authors.initials: S
authors.lastname: Liu
authors.forename: Liqing
authors.initials: L
authors.lastname: Li
authors.forename: Weijun
authors.initials: W
authors.lastname: Kang
mesh_terms: D005609:Free Radicals; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D008163:Luminescent Measurements / Q000379:methods*; D008165:Luminol; D012834:Silver
chemical_list: D005609:Free Radicals; D012834:Silver; D008165:Luminol; D006854:Hydrocortisone