Layers dendrimers

Mono- and Multi-Layer Dendrimer Self-Assembly... 

J.P. Markham, S.C. Lo, S.W. Magnnis, P.L. Burn, and I.D.W. Samuel, High-efficiency green phosphorescence from spin-coated single-layer dendrimer light emitting diodes, Appl. Phys. Lett., 80 2645-2647 (2002). 

TD Anthopoulos, JPJ. Markham, EB Namdas, IDW Samuel, SC Lo, and PL Burn, Highly efficient single-layer dendrimer light-emitting diodes with balanced charge transport, Appl. Phys. Lett., 82 4824 1826, 2003. 

There have been only very limited studies in literature on the exploitation of dendrimers in electrochemical DNA biosensors. The earliest report was by Wang et al on the chronopotentiometric detection of a 27-mer ss-DNA oligonucleotide of 2-layer and 4-layer dendrimers by adsorptive accumulation on carbon paste electrodes. The detection limits were found to be 3 and 12 pM for the 2- and 4- layers nucleic dendrimers respectively [159],... 

Hawker and Frechet525 via convergent attachment of preformed poly(benzyl ether) dendrons 4 to a poly-benzyl ester) monomer, 238. Continuation of the poly(benzyl ester) synthesis followed by coupling to a triphenolic core afforded the layered dendrimer 241. The primary synthetic requirement for the two different monomers is that the outermost dendritic layers must be chemically inert to the coupling and... 

CrespiUio, F. N., Emiha GhicaJ4., et al. A strategy for enzyme immobilization on layer-by-layer dendrimer-gold nanoparticle electrocatalytic membrane incorporating redox mediator. Electrochemistry communications,8(10), 1665-1670 (2006). 

Dichtel WR, Hecht S, Frechet JMJ (2005) Functioneilly layered dendrimers a new building block and its application to the synthesis of multichromophoric light-harvesting systems. Org Lett 7 4451 454... 

Chiral phosphorus-containing dendrimers which have ferrocene molecules at the periphery have been the subject of work by Majoral and co-workers. These materials will have obvious applications in catalysis. Layer-by-layer dendrimers, which are built up containing chiral ferrocenylphosphine molecules, have also been prepared, and their chiroptical and electrochemical properties have been investigated. A recent article covers the basic chemistry of ferrocene-containing liquid-crystalline polymers which stems from the extensive work of Deschenaux, who essentially pioneered the area. A ferrocene end-capped dendrimer has also been used in carbon monoxide sensing. The actual dendrimer, shown as 19, has 48 ferrocene molecules on the periphery. 

Fullerenes possess electronic and photophysical properties which make them natural candidates for the preparation of functional dendrimers. The attachment of a controlled number of dendrons on a core provides a compact insulating layer around the carbon sphere, and the... 

Numerous dendrimers, which contain coordination sites on the outer surface, within the macrostructure throughout all layers, and at the inner core have been prepared. In contrast,... 

Due to their well defined geometrical sizes, globular shapes, and uniform multiple surface functional groups, dendrimers are promising candidates for the construction of mono- or multi-layer films. 

Regen and Watanabe [158] fabricated multi-layers close to a thickness of 800 A by using fourth or sixth generation PAM AM dendrimers with 16 or 12 cycles, respectively. The construction techniques involved activation with K2PtCl4 on a silicon wafer containing amino groups on the surface, which was followed by deposition of the dendrimer layer. However, elimination of Pt2+ layer resulted in absence of layer growth, as examined by X-ray photoelectron spectroscopy. 

The surface of each layer has two types of single stranded arms (e.g. one 3 — 5 and one 5 — 3 strand) which can bind to other monomers to render 1st-and 2nd-generation dendrimers 25 and 26. Therefore the molecular scaffold grows exponentially with each sequential layer of hybridization. If an oligonucleotide contains a sequence complementary to those at the surface of these networks it should be hybridized. The remaining free sequences from the other type of arms then bind in a standard nucleic acid blot (after they are bound to... 

Fig. 24. Fluorine-containing 2nd-generation dendrimer 76 and 19F-NMR spectrum showing the different chemical environment in the two dendrimer-layers [91]... 

In a complementary approach the backbones of dendrimers are jacketed as tightly as possible with dendrons of the largest possible space demand. Here the dendrons serve as space filling parts to implement sufficient strain to the dendrimers backbone in order to stretch it to the extreme. A good example for this is dendrimer 22a with its third generation dendrons [15b]. The molecular dimensions obtained from MD-simulations in vacuo show that (a) it attains an almost stretched conformation, (b) the dendritic layer around the PPP backbone... 

M. Snejdakova, L. Svobodova, D.P. Nikolelis, J. Wang, and D. Hianik, Acetylcholine biosensor based on dendrimer layers for pesticides detection. Electroanalysis 15, 1185—1191 (2003). 

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