Determination of trace human chorionic gonadotropin by using multiwall carbon nanotubes as phosphorescence labeling reagent.
Taking advantage of the cutting effect of the strong oxidation of benzoyl peroxide [(C(6)H(5)CO)(2)O(2)] on the end of multiwall carbon nanotubes (MWNTs) to obtain water-soluble multiwall nanotubes (MWNTs') and the spiking effect of polyacrylamide (PA) on the room temperature phosphorescence (RTP) of MWNTs', a new phosphorescent labeling reagent, MWNTs'-PA, has been developed in this study. The product β-Ab(HCG)-MWNTs'-PA obtained by MWNTs'-PA labeling human chorionic gonadotropin-β-subunit three-dimensional core monoclonal antibody (β-Ab(HCG)) not only could maintain good RTP characteristics of MWNTs' but also could take specific immunoreaction with β-HCG to form β-HCG- β-Ab(HCG)-MWNTs'-PA, resulting in the increase of MWNTs' RTP signal. Thus, a new solid substrate room temperature phosphorescence immunoassay (SSRTPIA) for the determination of β-HCG has been established. The limits of detection (LODs) of the new method were 0.021pgspot(-1) for the direct way at 447/615nm (λ(ex)(max)/λ(em)(max)) and 0.016pgspot(-1) for the sandwich way at 447/614nm (λ(ex)(max)/λ(em)(max)). This sensitive, accurate, and precise method was used to determine β-HCG and diagnose human diseases by the direct way or the sandwich way, with the results coinciding with those obtained by chemiluminescence immunoassay. Meanwhile, the mechanisms of MWNTs' labeling β-Ab(HCG) and determining β-HCG are also discussed.
Department of Chemistry and Environmental Science, Zhangzhou Normal College, Zhangzhou 363000, People's Republic of China. zzsyliujiaming@163.com
Jia-Ming
JM
Liu
Xiao-Mei
XM
Huang
Ma-Lin
ML
Cui
Li-Ping
LP
Lin
Li-Hong
LH
Zhang
Zhi-Yong
ZY
Zheng
Shao-Qin
SQ
Lin
D000180:Acrylic Resins / Q000737:chemistry; D000911:Antibodies, Monoclonal / Q000276:immunology; D006063:Chorionic Gonadotropin / Q000097:blood*; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007118:Immunoassay; D049408:Luminescent Agents / Q000737:chemistry*; D008163:Luminescent Measurements; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D011247:Pregnancy; D013696:Temperature; D000099166:Polyacrylamides
D000180:Acrylic Resins; D000911:Antibodies, Monoclonal; D006063:Chorionic Gonadotropin; D049408:Luminescent Agents; D037742:Nanotubes, Carbon; D010100:Oxygen; D000099166:Polyacrylamides