Nanoparticle Chemiluminescent Analysis And Its Application In Immunoassay

Immunoassay plays a very important role in life sciences. It has been widely used in biochemistry, molecular biology and medical diagnostics. According to the nature of a label and the measurement, immunoassay can be classified as enzyme immunoassay, fluorescent immunoassay, electrochemical metalloimmunoassay, chemiluminescent immunoassay, bioluminescent immunoassay and so on. But with the development of the life sciences, the disadvantage of those routine methods has already been revealed. Then, it is very necessary to develop new analysis methods with high sensitivity, simple operation and universal applicability. Nanoparticles have become quite popular in research field of materials, owing to their many peculiar properties and their great high technology applied prospect.A CL immunoassay using silver nanoparticle as a label has been developed. The assay is based on a sandwich-type immunoreaction coupled with CL reaction of Ag⁺-Mn²⁺-K₂S₂O₈-H₃PO₄-Luminol system. First, the sandwich-type complex is formed in this protocol by the primary antibody immobilized on the polystyrene wells, the antigen in the sample, and the second antibody labeled with colloidal silver. Second, a large number of Ag⁺ were oxidatively released from the silver metal anchored on the sandwich-type complexes and then the human IgG was indirectly determined by the sensitive CL technique. As a new chemiluminescence-based nonisotopic immunoassay method, the method is simple in instrument, sensitive and has significant potential for the determination of biological analytes by labeling nanoparticles.Besides, chemiluminescent (CL) analytical method by using CL to determine Fe(OH)₃ nanoparticles and CdS quantum dots (QDs) has been developed. CL analysis is rapid, sensitive and does not require expensive instruments. The development of this method laid the foundation for the application of nanoparticles in biochemistry as a CL probes.