Layered polyelectrolyte assemblies

Hillberg, A.L. and Tabiizian, M. (2006) Biorecognition through layer-by-layer polyelectrolyte assembly in situ hybridation on living cells. Biomacromolecules, 7, 2742-2750. 

Evtugyn GA, Hianik T (2011) Layer-by-layer polyelectrolyte assembles involving DNA as a platform for DNA sensors. Curr Anal Chem 7(l) 8-34... 

Shenoy, D. B., Sukhorukov, G. B. Microgel-based engineered nanostructures and their applicability with template-directed layer-by-layer polyelectrolyte assembly in protein encapsulation. Macromol. Biosci. 2005, 5, 451 58. 

FIG. 6 Structures of an important class of polyelectrolytes used for deposition of layer-by-layer self-assembly. 

FIG. 7 Confocal laser scanning microscopy image of a fonr-layer polyelectrolyte/CdTe(S) nanocrystal shell assembled on 1.5-p,m-diameter ME particles. The polyelectrolyte film consists of two bUayers of PAH and PSS. (From Ref. 76.)... 

H. Kong, R Luo, C. Gao, and D. Yan, Polyelectrolyte-functionalized multiwalled carbon nanotubes preparation, characterization and layer-by-layer self-assembly. Polymer 46, 2472—2485 (2005). 

M. Houska, E. Brynda, and K. Bohata, "The Effect of Polyelectrolyte Chain Length on Layer-by-layer Protein/Polyelectrolyte Assembly - an Experimental Study," Journal Of Colloid And Interface Science 213, 140-147 (2004). 

We will discuss here applications of polyelectrolyte-modified electrodes, with particular emphasis on layer-by-layer self-assembled redox polyelectrolyte multilayers. The method offers a series of advantages over traditional technologies to construct integrated electrochemical devices with technological applications in biosensors, electrochromic, electrocatalysis, corrosion prevention, nanofiltration, fuel-cell membranes, and so on. 

Figure 2.25 Dependence of the catalytic current for the oxidation of p-D-glucose mediated by the redox polyelectrolyte film for different number of COx layers self-assembled with (PAH-Os) (COx) (n=m = 2, 4, 6). Taken from [182].

Electrode surfaces can be modified by redox polyelectrolytes via a sol-gel process, yielding random redox hydrogels or by layer-by-layer self-assembly of different redox and nonredox polyelectrolytes by alternate electrostatic adsorption from solutions containing the polyelectrolytes to produce highly organized redox-active ultrathin multilayers. 

Fendler, J.H. (2003) in Multilayer Thin Films Layer-by-Layer Self-assembled Polyelectrolytes and Nanoplatelets... 

The technique of alternating polyelectrolyte film construction has also been adapted to incorporate semiconductors into layered films. For example, multilayer films have been constructed by alternately dipping a quartz substrate into a solution of poly(diallylmethylammonium chloride) and then a solution of a stabilized CdS or PbS colloid (41). The layer-by-layer self-assembly of alternating polymer and metal sulfide is at least partially driven by the electrostatic attraction of the cationic polymer and the negative charge of the stabilized MC colloid particles. 

Figure 10.10 Layer-by-layer self-assembly of polyelectrolytes on a negatively charged silicon surface.

Michel M, Izquierdo A, Decher G et al (2005) Layer-by-layer self-assembled polyelectrolyte multilayers with embedded phospholipid vesicles obtained by spraying integrity of the vesicles. Langmuir 21 7854-7859... 

As briefly described previously in this chapter, layer-by-layer (LbL) assembly is a versatile method for construction of layered structures from various materials.48,49 Therefore, the LbL technique should be a very useful method for constructing layered mesoscopic structures. The LbL assembly concept was first suggested by Iler,50 but realized and established by Decher and coworkers.51 An outline of this technique is shown in Figure 2.12, where assembly between a cationic polyelectrolyte and anionic... 

Figure 13.2 Layer-by-layer (LbL) assembly of oppositely charged polyelectrolyte films via electrostatic interactions.10...

N.A. Kotov, I. Dekany, J.H. Fendler, Layer-by-Layer Self-Assembly of Polyelectrolyte-Semiconductor Nanoparticle Composite Films , J. Phys. Chem., 99,13065 (1995)... 

Based on these observations, Wang and Caruso [237] have described an effective method for the fabrication of robust zeolitic membranes with three-dimensional interconnected macroporous (1.2 pm in diameter) stmctures from mesoporous silica spheres previously seeded with silicalite-1 nanoparticles subjected to a conventional hydrothermal treatment. Subsequently, the zeolite membrane modification via the layer-by-layer electrostatic assembly of polyelectrolytes and catalase on the 3D macroporous stmcture results in a biomacromolecule-functionalized macroporous zeolitic membrane bioreactor suitable for biocatalysts investigations. The enzyme-modified membranes exhibit enhanced reaction stability and also display enzyme activities (for H2O2 decomposition) three orders of magnitude higher than their nonporous planar film counterparts assembled on silica substrates. Therefore, the potential of such structures as bioreactors is enormous. 

The layer-by-layer (LbL) assembly technique based on alternated adsorption of oppositely charged polyelectrolytes, enzymes and nanoparticles is one of simple methods of thin film formation on various surfaces [1,2]. Despite of wide application of this technique, a lack of understanding of some process details still exists. In particular, adsorption kinetics need clarification to optimize the time period and reagent concentration range required for deposition of a saturated layer of adsorbate on various surfaces. 

In the last decade hollow spheres are extensively studied in the context of application as containers of prolonged action for substances of the different chemical nature dmgs, cosmetics, dye. A number of methods for preparation of microspheres with the sizes ranging from nanometers to micrometers and consisting of various materials are developed. Polyelectrolye capsules have been produced by sequential adsorption of oppositely charged polyelectrolytes, also known as Layer-by-Layer (LbL) assembly onto the surface of colloidal particles followed by core dissolution [1-2]. Most of the capsules applications imply their chemical or physicochemical modification by influence of the ionic strength [3], pH [3], temperature... 

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