Highly sensitive homogenous chemiluminescence immunoassay using gold nanoparticles as label.
Homogeneous immunoassay is becoming more and more attractive for modern medical diagnosis because it is superior to heterogeneous immunoassay in sample and reagent consumption, analysis time, portability and disposability. Herein, a universal platform for homogeneous immunoassay, using human immunoglobulin G (IgG) as a model analyte, has been developed. This assay relies upon the catalytic activity of gold nanoparticles (AuNPs) on luminol-AgNO3 chemiluminescence (CL) reaction. The immunoreaction of antigen and antibody can induce the aggregation of antibody-functionalized AuNPs, and after aggregation the catalytic activity of AuNPs on luminol-AgNO3 CL reaction is greatly enhanced. Without any separation steps, a CL signal is generated upon addition of a trigger solution, and the CL intensity is directly correlated to the quantity of IgG. The detection limit of IgG was estimated to be as low as 3pg/mL, and the sensitivity was better than that of the reported AuNPs-based CL immunoassay for IgG.
Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, China.
Jing
J
Luo
Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, China.
Xiang
X
Cui
Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, China.
Wei
W
Liu
Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, China. Electronic address: libaoxin@snnu.edu.cn.
Baoxin
B
Li
D006046:Gold / Q000737:chemistry*; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D007074:Immunoglobulin G / Q000032:analysis*; D057230:Limit of Detection; D049449:Luminescence; D049408:Luminescent Agents / Q000737:chemistry*; D008163:Luminescent Measurements / Q000379:methods*; D008165:Luminol / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D012835:Silver Nitrate / Q000737:chemistry
D007074:Immunoglobulin G; D049408:Luminescent Agents; D008165:Luminol; D006046:Gold; D012835:Silver Nitrate
Chemiluminescence; Gold nanoparticles; Homogeneous immunoassay