Sensitive Chemiluminescence Immunoassay by Capillary Electrophoresis with Gold Nanoparticles

摘要

This technical note describes a new chemiluminescence immunoassay hyphenated to capillary electrophoresis (CE-based CL-IA) with gold nanoparticles (AuNPs) technique for biological molecules determination. AuNPs were used as a protein label reagent in the light of its excellent catalytic effect to the CL reaction of luminol and hydrogen peroxide. AuNPs conjugate with antibody (Ab) to form tagged antibody (Ab~(*)), and then Ab~(*) link to antigen (Ag) to produce an Ab~(*)-Ag complex by a noncompetitive immunoreaction. The mixture of the excess Ab~(*) and the Ab~(*)-Ag complex was baseline separated and detected within 5 min under the optimized conditions. This new protocol was evaluated with human immunoglobulin G (IgG) as the target molecule. The calibration curve of IgG was in the range of 0.008-5 (mu)g/mL with a correlation coefficient of 0.995. The detection limit (S/N velence 3) of IgG was 1.14 X 10~(-3) (mu)g/mL (7.1 pmol/L, 0.39 amol). The proposed AuNPs enhanced CE-based CL-IA method was successfully applied for the quantification of IgG in human sera from patients. It proves that the present method could be developed into a new and sensitive biochemical analysis technique.