ASSEMBLY OF THIN-FILMS BY MEANS OF SUCCESSIVE DEPOSITION OF ALTERNATELAYERS OF DNA AND POLY(ALLYLAMINE)

We have recently introduced a new method of creating ultrathin films b ased on the electrostatic attraction between opposite charges. Consecu tively alternating adsorption of anionic and cationic polyelectrolytes leads to the formation of multilayer assemblies. Here, we extend our concept to the procedure of ultrathin (100-500-angstrom) film growth w ith alternation of DNA and poly(allylamine)molecular layers. Multilaye r buildup was monitored by small-angle X-ray reflectivity; the step of growth for layer pairs of DNA/poly(allylamine) was 40 angstrom. The r elationship between this growth mechanism and the process of natural c omplex formation between DNA and polyamines (spermine, spermidine, etc .) may be of interest.