The Application Of Surface-Enhanced Raman Spectroscopy For Immunoassay

Surface-enhanced Raman spectroscopy (SERS) has been proven to be a powerful tool inresearch and applications in various fields. Combined with gold nanoparticle labeling and SERStechnique, spectral measurements on immunoassay are described.Different molecules, thiophenol (TP), p-aminothiophenol (PATP), and 4,4-Bipyridine (4,4-bipy) were used as SERS-reporters. Because the different reporter molecules have differentmolecular structures, the adsorption configurations of them are discussed.Here, the relationship between SERS intensity of immunogold nanoparticle and the size ofspheroid gold nanoparticles, coverage of the reporter molecules, time of modifying of SERSreporters and the wavelength of laser were investigated. By controlling appropriate modificationconditions, high-quality SERS signal are obtained.Due to specific adsorption of antibody and antigen, by immobilizing goat anti-mouse IgG orsheep anti-human IgG antibody on a glass slide modified by special organic molecules, theantibody /antigen /reporter-labeled immunogold nanoparticle sandwich assay was build forSERS measurements. Therefore, we can identify the single type biospecific species thoughdetection of the SERS signal of the reporter molecules which are coimmobilized withimmunogold nanoparticle. Similarly, by modifying different SERS reporter molecules on, wecan detect special one in multi- biospecific species.