Immunonanogold Catalytic Resonance Scattering Spectral Detection Of IgG

Partâ… IntroductionBasic knowledge of light scattering, resonance scattering and its application in analytical chemistry and nanoparticles were introduced. Summarized the preparation, identification and assembly of gold nanoparticles and its application in biochemical analysis in recent years. The analytical progress of IgG was also reviewed.Partâ…¡Resonance Scattering Spectral Study of HAuCl4-NH2OH-nanogold catalytic systemAu, Ag, Pt, Pd, Fe3O4 nanoparticles have catalytic effect on the particle reaction of HAuCl4-NH2OH to produce gold particles in big size, that exhibit strongest resonance scattering (RS) peak at 796 nm. The enhanced resonance scattering intensity at 796 nm is linear to nanogold concentration in the range of 0.25¹0.15 nM, 1.27⁵0.76 nM, 1.27⁴4.16 nM, 1.83⁵0.76 nM and 5.08²65.18 nM nanogold in size of 5, 10, 15, 30 and 50 nm respectively, with a detection limits of 0.24 nM, 0.99 nM, 1.18 nM, 1.19 nM and 4.15 nM. Based on this, a new RS method was established to determine ultratrace nanogold.Partâ…¢A detection of ultratrace IgG using immunonanogold catalytic Gold-enhanced Resonance scattering spectralA 10 nm-nanogold was used to label goat anti-human IgG (GIgG) to obtain nanogold-labeled GIgG(AuGIgG). In pH 2.27 citrate-HCl buffer solution, AuGIgG showed strong catalytic effect on the reaction between HAuCl₄-NH₂OH to form big gold particles that exhibited a resonance scattering peak at 796 nm. Under the chosen conditions, AuGIgG combined with IgG to form immunocomplex of AuGIgG-IgG that can be separated by centrifuging at 16000 rpm. AuGIgG in centrifuging solution has also catalytic effect on the reaction. On those grounds, an immunonanogold catalytic resonance scattering assay for IgG was proposed. With addition of IgG, the AuGIgG in centrifuging solution decreased, the resonance scattering intensity at 796 nm I796nm decreased linearly. The decreased intensityâ–³I796nm was linear to IgG concentration in the range of 0.08～16.0 ng.mL^-1, with a detection limit of 0.02 ng.mL^-1. This assay was applied to analysis of IgG in sera, with sensitivity, selectivity and rapidity.Partâ…£A Novel and Highly Sensitive Immunonanogold Catalytic Copper-enhanced Resonance Scattering Spectral BioassayIn the NaAc-HAc buffer solution, Au, Ag, Pt, Pd, Fe3O4, and Cu2O nanoparticles have catalytic enhancement effect on the reduction of Cu2+ by ascorbic acid (AA) to form large size copper particles that exhibit a strong resonance scattering peak at 610nm. The new nanocatalytic reaction was studied firstly by resonance scattering (RS) spectral technique. Results showed that nanogold exhibited strongest catalytic enhancing effect. The RS intensity at 610nm I610 nm increased linearly with the concentration of 0.02～1.63 nM, 0.041～1.22 nM and 0.118～4.71 nM nanogold in size of 5 nm, 10 nm and 15 nm, with a detection limit of 0.013nM, 0.034nM and 0.10 nM, respectively. A new strategy of immunonanogold catalytic RS method was set up, combined the catalytic effect of immunonanogold on the reaction between CuSO4 and AA with the RS detection technique. As a model, 0.03 ng.mL^-1 to 7.5 ng.mL^-1 IgG can be assayed by this immunonanogold catalytic RS method, with a detection limit of 0.015 ng.mL^-1.