Acetal-functionalized polymer particles useful for immunoassays

Abstract

The synthesis of core-shell type polystyrene monodisperse particles with surface acetal groups was carried out by a two-step emulsion polymerization process. In a first step, the core was synthesized by batch emulsion polymerization of styrene (St), and in the second step, the shell was polymerized by batch emulsion terpolymerization of styrene, methacrylic acid (MAA), and methacrylamidoacetaldehyde dimethyl acetal (MAAMA), using the seed obtained previously. With the aim of analyzing the effect of the thickness of the shell, the pH of the reaction medium and the weight ratio of the termonomers to prepare the shell, on the amount of the functionalized groups, several core-shell type latex particles were synthesized by two-step emulsion polymerization in a batch reactor. The latexes were characterized by TEM and conductimetric titration to obtain the particle size distribution and the amount of carboxyl and acetal groups on the surface, respectively. Looking for the applicability of the synthesized latexes in immunoassays, IgG a-CRP rabbit antibody was covalently bonded to the surface of the particles synthesized in neutral medium. The complex latex-protein was immunologically active against the CRP antigen. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1605–1610, 1997