Study On The Protein Analysis And Immunoassay By Using Nanoparticles As Probes

The protein analysis and immunoassay play a very important role in life sciences. It is extensively used in biochemistry, molecular biology and medical diagnostics. With the development of the life sciences, the disadvantage of the routine methods has already been revealed. Then, it is very necessary to study the new analysis methods of high sensitivity, simple operation and universal applicability. In this dissertation, based on the interaction between the nanoparticles and the proteins, spectrophotometry assay of proteins by using ferric nanoparticle as probe and gold nanoparticles-based chemiluminescence immunoassay were investigated. Ferric nanoparticles interact with proteins by electrostatic forces and aggregate to form large particles, which result in strong absorption to visible light. The absorbance is well proportional to the concentration of proteins in the range of 0.1～10.0 mg l-1. Based in these, a new spectrophotometry assay for protein determination was established by using ferric nanoparticles as probes. The detection limit for bovine serum albumin (BSA) is 34 μg l-1. The proposed method has been employed for the determination of total proteins in human serum with satisfactory results. A chemiluminescence (CL) immunoassay using gold nanoparticle as a label has been developed. The assay is based on a sandwich-type immunoreaction coupled with CL reaction of AuCl4--luminol-H2O2 system. The AuCl4-, which is the dissolving product of the gold nanoparticles labeled to the rabbit-anti-goat immunoglobulin G (IgG), served as an analyte in the CL reaction for the indirect measurement of goat-anti-human IgG. The logarithm of the concentration of goat-anti-human IgG is proportional to the chemiluminescence intensity in the range of 5 ng ml-1～10 μg ml-1 and the detection limit (3σ) is 1.5 ng ml-1. This method has been successfully applied to the determination of goat-anti-human IgG in serum samples. As a new chemiluminescence-based nonisotopic immunoassay method, the method has significant potential for the...