Nanoparticles electrostatic assembly

Cruickshank, K. and A. Downard. Electrochemical stability of citrate-capped gold nanoparticles electrostatically assembled on amine-modified glassy carbon. Electrochim. Acta 54, 2009 5566—5570. 

Figure 6.9 A schematic representation of orthogonal process for nanoparticles self-assembly (a) a patterned sihcon wafer with Thy-PS and PVMP polymers fabricated through photolithography and (b) orthogonal surface functionahzation through Thy-PS/DP-PS recognition and PVMP/acid-nanoparticle electrostatic interaction. Reprinted with permission from Xu et al. (2006). Copyright 2006 American Chemical Society.

NIR-absorbing metal nanostructures are appealing for biomedical imaging applications for reasons discussed previously, and this includes biological applications of SERS. For example, NIR-active core-shell superparticles have been prepared by the electrostatic assembly of densely packed Au nanoparticles on submicron silica spheres.34 Such superparticle probes can be implanted into mammalian cells by cationic transfection,186 and have produced SERS signals from absorbed DNA.187 Biocompatible SERS nanoparticle tags can also be used as contrast agents for in vivo detection, as previously discussed.169... 

Electrostatic assembly, which involves attractive forces between two oppositely charged entities (polymers, nanoparticles, and substrates), has been proposed in the pioneering work of Her for the assembly of two- and three-dimensional structures.22 The LbL assembly of charged polyelectrolytes was later reported by Decher et al. for the fabrication of multilayer films of polyelectrolytes.10 23 Their technique is based on the consecutive adsorption of polyanions and polycations from dilute aqueous solutions onto a charged substrate (Fig. 13.2). 

The direct LbL assembly of oppositely charged nanoparticles, which did not involve polyelectrolytes, was also examined. Sastry et al. demonstrated the formation of alternating layers of gold and silver nanoparticles via sequential electrostatic assembly.36 In the absence of polyelectrolytes, the effective charging of gold and silver nanoparticles was accomplished by the adsorption of 4-aminothiophenol and 4-carboxythiophenol molecules on the nanoparticle surfaces, respectively. The multilayer films were stable up to 100°C. 

Sayle et al. (2008) also developed (Figure 9) a route exploiting the classical atomistic simulation to make combined studies of theoretical and experimental works. A typical selected system is ceria. Since the pair potential model based on electrostatic interaction and Buckingham short range presentations are often adequate to describe the fluorite structure of ceria, Sayle et al. explored the application of such models in nano-sized particles. A series of works have been reported on the assembly behaviors of nano-building blocks into complex nanostructures, including the ceria nanoparticles self assembly in ice mold (Karakoti... 

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 use of nanoparticle arrays to generate surface-confined architectures has been extensively studied by Willner and co-workers [6]. The structural motif involves the sequential electrostatic assembly of nanoparticles and the desired molecules on planar electrodes. An ITO substrate is functionalized using an aminosilane molecule to yield a charged surface. Negatively charged citrate-stabilized gold... 

HoUow Spheres from Electrostatic Assembly of Nanoparticles Through... 

Nanoparticle controllable assembly refers to the assembly of nanoparticles into controlled nanostructures (wires, rods, belts, rings, tubes, thin films, superlattices, and sophisticated 3D nanostructures) via interactions like electrostatic interaction, covalent interaction, metal-Ugand interaction, etc. 

Sastry M, Electrostatic assembly of nanoparticles , in Nanoparticles Building Blocks for Nanotechnology (ed. Rotello VM), New York, Kluwer Academic/ Plenum Publishers, 2004, pp 225-250. 

Patra D, Vangal P, Cain AA, Cho C, Regev O, Grunlan JC. Inorganic nanoparticle thin film that suppresses flammabihty of polyurethane with only a single electrostatically-assembled bUayer. ACS Appl Mater Interfaces September 2014 6 16903-8. 

Kostiainen M, Hiekkataipale P, Laiho A, Lemieux V, Seitsonen J, Ruokolainen J, Ceci P (2013) Electrostatic assembly of binary nanoparticle superlattices using protein cages. Nat Nanotechnol 8 52-56... 

M. G. Warner and J. E. Hutchison. Linear assemblies of nanoparticles electrostatically organized on DNA scaffolds. Nature Materials 2 (4), 272-277 (2003). 

Lev et al. have studied chemical methods to counteract nerve agents and remediate organophosphate (OP) contamination by means of nanoparticles, polymers, and nanofibers functionalized by a-nucleophilic agents [38, 39], Fibrous mats functionalized with a-nucleophilic oxime moieties were prepared by either electrospinning blends of polyacrylamidoxime and PAN or surface oximation of prefabricated PAN fibrous mats and demonstrated to possess a pronounced capability to hydrolyze chemical nerve agent simulants in the presence of moisture [39]. The layer-by-layer electrostatic assembly technique offers another strategy for electrospun fiber surface functionalization [40]. For the application in protective fabrics, Lee et al. demonstrated that electrospun fibers used as the substrate for titanium dioxide nanoparticle coatings resulted in increased specific substrate surface areas of about 10 that of the flat film, which enhanced photocatalytic decomposition of toxic industrial chemicals (Fig. 14.4a-c) [41,42]. 

Sastry, M., Kumar, A., Datar, S., Dharmadhikari, C.V., and Ganesh, K.N. (2001). DNA-mediated electrostatic assembly of gold nanoparticles into linear arrays by a simple drop-coating procedure. Appl. Phys. Lett.s 78 (19), 2943-2945. 

Sharma N, Top A, Kiick KL et al (2009) One-dimensional gold nanoparticle arrays by electrostatically directed organization using polypeptide self-assembly. Angew Chem Int Ed 48 7078-7082... 

The use of DNA as a template to fabricate mesoscale structures was also demonstrated in a recent work of Torimoto and coworkers. They used preformed, positively charged 3-nm CdS nanoparticles with a thiocholine-modified surface to be assembled into chains by using the electrostatic interaction between positively charged nanoparticle snr-faces and the phosphate groups of DNA. As determined by TEM analysis, the CdS nanoparticles were arranged in a qnasi-one-dimensional dense packing. This revealed interparticle distances of about 3.5 nm, which is almost equal to the height of one helical tnm of the DNA double strand [98]. 

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