Immunoassay using probe-labelling immunogold nanoparticles with silver staining enhancement via surface-enhanced Raman scattering.
This paper reports a novel immunoassay based on surface-enhanced Raman scattering (SERS) and immunogold labelling with silver staining enhancement. Immunoreactions between immunogold colloids modified by a Raman-active probe molecule (e.g., 4-mercaptobenzoic acid) and antigens, which were captured by antibody-assembled chips such as silicon or quartz, were detected via SERS signals of Raman-active probe molecule. All the self-assembled steps were subjected to the measurements of ultraviolet-visible (UV-vis) spectra to monitor the formation of a sandwich structure onto a substrate. The immunoassay was performed by a sandwich structure consisting of three layers. The first layer was composed of immobilized antibody molecules of mouse polyclonal antibody against Hepatitis B virus surface antigen (PAb) on a silicon or quartz substrate. The second layer was the complementary Hepatitis B virus surface antigen (Antigen) molecules captured by PAb on the substrate. The third layer was composed of the probe-labelling immunogold nanoparticles, which were modified by mouse monoclonal antibody against Hepatitis B virus surface antigen (MAb) and 4-mercaptobenzoic acid (MBA) as the Raman-active probe on the surface of gold colloids. After silver staining enhancement, the antigen is identified by a SERS spectrum of MBA. A working curve of the intensity of a SERS signal at 1585 cm(-1) due to the [small nu](8a) aromatic ring vibration of MBA versus the concentration of analyte (Antigen) was obtained and the non-optimized detection limit for the Hepatitis B virus surface antigen was found to be as low as 0.5 [micro sign]g mL(-1).
Xu
Shuping
S
Key Laboratory for Supramolecular Structure and Material of Ministry of Education, Jilin University, Changchun 130021, P. R. China.
Ji
Xiaohui
X
Xu
Weiqing
W
Li
Xiaoling
X
Wang
Lianying
L
Bai
Yubai
Y
Zhao
Bing
B
Ozaki
Yukihiro
Y
D000818:Animals; D006514:Hepatitis B Surface Antigens / Q000032:analysis*; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D051379:Mice; D036103:Nanotechnology / Q000379:methods; D016622:Silver Staining; D013059:Spectrum Analysis, Raman / Q000379:methods
D006514:Hepatitis B Surface Antigens