Nanofabrication of Ordered Multilayers by
Alternate Adsorption of Polyions, Proteins and Nanoparticles:
From Planar Films to Microtemplates.
1.
General idea of the layer-by-layer assembly, polyanion / polycation
films.
2.
Protein / polyion multilayers, sequential reactions in multiprotein
films.
3.
Ordered nanoparticle / polyion films; conception of
"polyion electrostatic glue."
4.
Shell
assembly onto nanospheres and nanotubules.
Empty polyion capsules.
Layer-by-layer self-assembly of molecularly
organized films was generalized for use with linear polyions, nanoparticles, dye
and proteins. The formation of alternate outermost layers of the opposite charge
at every adsorption cycle is the key point of the procedure. An alternate
assembly of linear polyanions and polycations typically provides 1-2 nm growth
step for a bilayer, and a number of bilayers, which can be built up, are
two-three hundreds.
Protein architecture: Multilayer buildup by
alternation of linear polyions and 20 different proteins was elaborated. Enzymes
in films preserved bioactivity. Film-superlattices containing ordered layers of
more than one protein species were constructed. Multi-enzymatic sequential
reactions with directed transfer of products were realized.
We designed ordered molecular films containing from 1 up to 50 monolayers of 10, 45 and 75 nm diameter nanoparticles connected by polycation interlayers. The conception of "polyion glue" for nanoparticle multilayer architecture permitted to assemble films with planned ordering of silica, TiO2, CeO2, Al2O3, MnO2.
An assembly of organized nanoparticle shells onto microspheres was performed: firstly, by adsorption of polycation polyethyleneimine we converted surface charge of negative 300-nm diameter latex to the positive one, and at the second step we adsorbed an ordered shells of 75-nm or 45-nm silica, and gold. Hollow shells from polyion formed on soluble latex precursors were loaded with enzymes and drugs for a controllable release. In the second approach a sequential treatment of 500-nm diameter lipid tubules with polyions and negatively charged nanoparticles (silica, gold) resulted in formation of nanoparticle “caps” which sealed the end of the tubules. Addition of 1 % of charged lipids during the tubule formation and application of the described above procedure gave nanoparticle helixes inside the tubules.
1.
Book: “Protein Architecture: Interfacing molecular assembly and
immobilization biotechnology.” Editors: Y.Lvov and H.Mohwald, M. Dekker
Publ, NY, 2000, p.1-396
2.
Y. Lvov, R. Price, B. Gaber, J. Schnur, Langmuir, 2000, v.26,
5932-5936 “Nanopatterning on biologically derived microstructures”
3.
Y. Lvov, J.
Rusling, D. Thomsen, T. Kunitake, J.
Chem. Soc., Chem. Commun., 1998, 1229-1230 “High-speed multilayer assembly
by alternate adsorption of nanoparticles and linear polycation”.
4.
Y. Lvov, Z.
Lu, J. Rusling, J. Am. Chem. Soc., 1998, v.120, 4073-4080 “Direct electrochemistry
of myoglobin and cytochrome P450 in alternate layer-by-layer films with DNA and
other polyions”