AuNPs monodisperse

Owing to the simphcity and versatility of surface-initiated ATRP, the above-mentioned AuNP work may be extended to other particles for their two- or three-dimensionally ordered assemblies with a wide controllabiUty of lattice parameters. In fact, a dispersion of monodisperse SiPs coated with high-density PMMA brushes showed an iridescent color, in organic solvents (e.g., toluene), suggesting the formation of a colloidal crystal [108]. To clarify this phenomenon, the direct observation of the concentrated dispersion of a rhodamine-labeled SiP coated with a high-density polymer brush was carried out by confocal laser scanning microscopy. As shown in Fig. 23, the experiment revealed that the hybrid particles formed a wide range of three-dimensional array with a periodic structure. This will open up a new route to the fabrication of colloidal crystals. 

The third class of AuNPs-dendrimer nanomaterials is Nanoparticle Cored Dendrimers (NCDs). The first report on this topic describes a new strategy in which Frechet-type dendrons with a single thiol group at the focal point were used as a surface stabilizer of Au NPs. These dendronized Au NPs were synthesized using a modification of the two-phase Brust-Schiffrin method, giving rise to highly stable and very monodisperse Au NPs of small size (about 2.4—3.1 nm) [129] (Figure 3.13). 

Similar to covalent interaction, AuNPs can also be self-assembled onto the electrode surface by electrostatic interaction (Figure 8). Nowadays, electrostatic self-assembly of nanomaterials on functionalized surfaces is a versatile approach for generating monodispersed 2D arrays [64-67], Surface functionalization can be performed by self-assembly of ionic species of a particular charge onto the substrate. Onto this charged surface, species of the opposite charge can be adsorbed, such as the protecting shell of the nanostructures. An... 

Filter the cooled AuNPs solution through a 0.45 pim Gelman membrane filter. The resulting solution contains spherical monodisperse AuNPs of about 13 nm in diameter, which can be determined by transmission electron microscopy (TEM) and UV-Vis spectroscopy as shown in Fig. 2 (see Note 4). 

Good dispersion of RDNA-AuNPs is important detection performance. The monodisperse RDNA-modified AuNPs should have the same color as the original citrate-reduced AuNPs. If the color of solution turns to blue or purple, indicating the formation of AuNPs aggregates, this batch of RDNA-AuNPs cannot be used further. Store the RDNA-AuNP conjugates away from direct sunlight at 4°C. Do NOT freeze. For consistent results, we recommend that RDNA-AuNPs should be used within 2-3 weeks of preparation. 

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