Dendrimers gold nanoparticles

Scheme 3.20 Dendrimer-gold nanoparticle composite prepared from G5-PAMAM dendrimer and Au NPs bearing —COOH groups.

To verify the structure of dendrimer-gold nanoparticles, gold nanoparticles synthesized by reduction of HAuCl4 with sodium borohydride in the presence of... 

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). 

Lundgren, A., Hed, Y., Oeberg, K., SeUbom, A., Fink, H., Lowenhielm, P., Kelly, J., Malkoch, M., BergUn, M. Self-Assembled Arrays of Dendrimer-Gold-Nanoparticle Hybrids for Functional Cell Studies. Angew. Chem. Int. Edit. 50(15), 3450-3453 (2011). doi 10.1002/Anie.201006544... 

Spherical vaterite crystals were obtained with 4-mercaptobenzoic acid protected gold nanoparticles as the nucleation template by the carbonate diffusion method [51]. The crystallization of calcium carbonate in the absence of the 4-MBA capped gold nanoparticles resulted in calcite crystals. This indicates that the polymorphs of CaCOj were controlled by the acid-terminated gold nanoparticles. This result indicates that the rigid carboxylic acid structures can play a role in initiating the nucleation of vaterite as in the case of the G4.5 PAMAM dendrimer described above. 

Figure 8.30 Synthesis of dendrimer-functionalized gold nanoparticles.

Shi, X., Wang, S., Sun, H., and Baker Jr., J.R. (2007) Improved biocompatibility of surface functionalized dendrimer-entrapped gold nanoparticles. Soft Matter 3, 71-74. 

The possibility of using electrostatic charge attraction has been exploited in the preparation of gold dendrimer encapsulated nanoparticles (DENs), which under appropriate conditions can be fully distributed along the surface of monodispersed MWCNTs (Fig. 3.21) [103]. 

Figure 6.2 (a) Gold nanoparticles assembled using PAMAM dendrimers and (b) small angle... 

Figure 6.3 UV visible spectra of assembled gold nanoparticle thin films by dendrimers of different generations ranging from GO to G4. Reprinted with permission from Srivastava, Frankamp, et al. (2005). Copyright 2005 American Chemical Society.

Srivastava S, Frankamp BL, Rotello VM. Controlled plasmon resonance of gold nanoparticles self-assembled with PAMAM dendrimers. Chem Mater 2005 17 487-490. 

Figure 3.13 Synthesis of gold nanoparticle-cored dendrimers using Frechet-type dendrons.

Finally, ferrocenyl units have been incorporated into the perimeter of dcndrimcric polymers by Astruc and coworkers.40 Gold nanoparticles form the core of the dendrimers, with the branched units with terminal ferrocene units coordinated to the gold surface via... 

Figure 6.2 Dendrimer and component segments with branched arms radiating from a gold nanoparticle, and with ferrocene units at the perimeter of the nanosphere. From Astruc et al., reference 40. Reproduced with permission.

The stepwise construction of self-assembled organic/inorganic multilayers based on multivalent supramolecular interactions between guest-functionalized dendrimers and nanoparticles and host-modified gold nanoparticles has been developed, yielding supramolecular LbL assembly (Fig. 13.8).12 Multilayer thin films composed of... 

An interesting example of the latter was accomplished by Reinhoudt and coworkers, who employed cyclodextrin (CD) functionalized self-assembled mono-layers (SAMs) to build up layer-by-layer (LBL) thin films via alternating host-guest interactions with functionalized dendrimers and gold nanoparticles [118,... 

The LBL self-assembly onto the CD functionalized surface requires at least two complementary substrates in order that multiple layers can be built up upon repeated alternating applications of the substrates, until a desired thickness has been achieved. Reinhoudt and coworkers chose the self-assembled interaction between CD-modified gold nanoparticles and either adamantyl- or ferrocene-functionalized dendrimers, which in turn were composed either of poly(propyleni-mine) (PPI) or poly(amidoamine) (PAMAM) [118, 122]. 

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