Chemical Modifications on Polystyrene Latex: Preparation and Characterization for Use in Immunological Applications

Polystyrene latex microspheres are efficient supports for immunological reactions. In the presence of suitable functional groups these microspheres may react by covalent binding with antigens or antibodies and have been extensively used in immunoassay technique. By using the emulsion polymerization and diazotization methods, a kind of functionalized latex was prepared. The preparation of this latex consisted of six syntheses of polystyrene followed by nitration, amination and diazotization. A narrow distribution of particle size was obtained in all the cases. The synthesis that presented 98% of monomer conversion and the largest particle size diameter 0.2 ± 0.05 μm was chosen for the subsequent chemical treatments. The chemical characterizations of every step were performed by Fourier transform infrared and Raman spectroscopies. The particle size was determined by a submicrometer particle analyzer and scanning electron microscopy. The polydiazostyrene latex obtained was sensitized using bovine serum albumin (BSA) and when it was submitted to agglutination assay in the presence of a rabbit serum containing specific antibodies to BSA demonstrated efficient results. © 1997 John Wiley & Sons, Ltd.