RESUMEN
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.
Asunto(s)
Acroleína/química , Polímeros/química , Poliestirenos/química , Albúmina Sérica/metabolismo , gammaglobulinas/metabolismo , Adsorción , Marcadores de Afinidad , Aglutinación , Sitios de Unión , Compuestos de Dansilo/química , Colorantes Fluorescentes/química , Humanos , Hidrazinas/química , Látex/química , Matemática , Microscopía Electrónica de Rastreo , Nefelometría y Turbidimetría , Tamaño de la Partícula , Fenilhidrazinas/química , Pirenos/química , Estándares de Referencia , Albúmina Sérica/química , Propiedades de Superficie , gammaglobulinas/químicaRESUMEN
Poly(methyl methacrylate-methacrylic acid-2-hydroxyethyl methacrylate) latex (ACRYLAT) was synthesized by radical precipitation polymerization. The mass median diameter (MMD) and the geometrical standard deviation (GSD) of the ACRYLAT particles were 138 nm and 1.2, respectively. The concentration of the titrable carboxylic groups in the surface layer of latex particles was equal to 8.41 x 10(-6) mol m-2. Latex was able to bind up to 2.82 x 10(-7) mol of 1-aminopyrene per 1 m2 of the surface of the latex particles due to the ionic interactions between carboxylate anions and ammonium cations of protonated 1-aminopyrene. ACRYLAT was able to immobilize covalently human serum albumin in amounts up to 0.23 mg m-2. Aggregation of ACRYLAT with immobilized HSA, induced with specific antibodies (anti-HSA), was investigated turbidimetrically. The results indicated that in the model turbidimetric immunoassay, ACRYLAT coated with HSA can be used for the detection of anti-HSA in the goat anti-HSA serum diluted from 50 to 7000-fold. Immobilization of rabbit antibodies to plasminogen (anti-Plg) to ACRYLAT via the epsilon-aminocaproic acid linkers provided particles which were used for the development of the turbidimetric immunoassay for plasminogen. In this assay plasminogen could be detected in concentration ranging from 0.75 to 75 micrograms ml-1 in the blood plasma.