Adsorption and covalent immobilization of human serum albumin (HSA) and gamma globulins (gamma G) onto poly(styrene/acrolein) latexes with pyrene, dansyl, and 2,4-dinitrophenyl labels.

The poly(styrene/acrolein) latexes (P(SA)1 and P(SA)2), differing in poly(acrolein) content, were synthesized by the emulsifier-less emulsion-precipitation polymerization of styrene and acrolein. The fraction of poly(acrolein) in the surface layer was 0.35 and 0.50, for the P(SA)1 and P(SA)2 latex, respectively. Latexes were labelled with 2,4-dinitrophenylhydrazine (DNPH), dansylhdrazine (DAH), and 1-aminopyrene (APY). Surface concentration of labels varied from 4.20.10(-7) mol m-2 (for APY label on P(SA)1 latex) to 1.54.10(-6) mol m-2 (for DNPH label on P(SA)2 latex) reflecting the fraction of polyacrolein in the surface layer and bulkiness of the label. The differences between adsorption and covalent immobilization of human serum albumin and gamma globulins onto the P(SA)2 latex and onto its derivatives labelled with the 2,4-dinitrophenyl (DNP), dansyl (DA), and pyrene (PY) groups were small. The observation conforms to the hypothesis that polyacrolein forms domains on the surface of the P(SA) latexes and that after labelling some aldehyde groups are still available for the covalent immobilization of proteins. Labelled and parent latexes were used in the model slide and turbidimetric aggregation tests for the goat anti-HSA. The fluorescent latexes, labelled with APY and DAH, and latexes labelled and with DNPH were found to be suitable for the model tests, similarly as the nonlabelled ones, however, some differences in the sensitivity, depending on the presence and the nature of labels, were noticed. The standard goat anti-HSA serum (Sigma) was detected at maximum dilution equal to 2000 in the slide test, and in the dilution region from 1.8.10(3) to 4.7.10(6) times in the turbidimetric test.