Determination of human IgG by solid substrate room temperature phosphorescence immunoassay based on an antibody labeled with nanoparticles containing Rhodamine 6G luminescent molecules.
Luminescent silicon dioxide nanoparticles (R-SiO2) with size of 50 nm containing Rhodamine 6G (R) were synthesized by sol-gel method. In the presence of Pb(Ac)2 as a heavy atom perturber, the particle can emit intense and stable room temperature phosphorescence signal of R, respectively, on polyamide membrane, with the lambda(ex)(max)/lambda(em)(max) = 470/635 nm for R. Our research indicates that the specific immune reaction between goat-anti-human IgG antibody labeled with R-SiO2 and human IgG can be carried on polyamide membrane quantitatively, and the phosphorescence intensity was enhanced after the immunoreactions. Thus, a new method of solid substrate room temperature phosphorescence immunoassay (SS-RTP-IA) for the determination of human IgG was established basing on antibody labeled with the nanoparticles containing binary luminescent molecules. The linear range of this method is 0.0624-20.0 pg spot(-1) of human IgG (corresponding concentration, 0.156-50.0 ng mL(-1); sample volume, 0.40 microL spot(-1)). The regression equations of working curves are delta I(p) = 88.16. + 16.79 m(IgG) (pg spot(-1)) (485/646 nm, r = 0.9997). Detection limits calculated by 3Sb/k are 0.017 pg spot(-1). For samples containing 0.156 and 50.0 ng mL(-1) of IgG, we measured repeatedly for 11 times, RSDs are 3.9 and 2.8%, respectively. This method is sensitive, accurate and of high precision.
Jia-Ming
Liu
L
Department of Chemistry, Zhangzhou Normal College, Zhangzhou 363000, PR China. zzsyliujiaming@163.com
Hui
Zhu Guo
ZG
Aihong
Wu
W
Pingping
Li
L
Huanhuan
Xu
X
Li
Long-Di
LD
Liu
Zhen-Bo
ZB
D000906:Antibodies; D006801:Humans; D007118:Immunoassay; D007074:Immunoglobulin G / Q000032:analysis* / Q000276:immunology; D007700:Kinetics; D008163:Luminescent Measurements; D049329:Nanostructures; D012235:Rhodamines; D012822:Silicon Dioxide
D000906:Antibodies; D007074:Immunoglobulin G; D012235:Rhodamines; C026188:rhodamine 6G; D012822:Silicon Dioxide