Nanoparticles, gold

Gold biochemistry has seen much development in recent years. The interaction of gold complexes with proteins and mitochondria, the possible role(s) of gold(III) in vivo, and the potential for developing future therapies using gold nanopartides are 

2 Higby, G.J. (1982) Gold in medicine a review of its use in the west before 1900. Gold Bulletin, 15, 130—140. 

3 Kean, W.F., Lock, C.J.L. and Floward-Lock, FI. (1991) Gold complex research in medical science difficulties with experimental design. Injlammopharmacologf, 1, 103-114. 

4 Permerman, R.A. and Ryan, R.R. (1972) The di-aquo proton in hydrogen tetracyanoaurate(III) dehydrate. Acta Crystallographica, B28, 1629—1632. 

5 Weishaupt, M. and Strahle, J. (1976) Crystal structure and vibrational spectrum of tetraamminegold(III) nitrate. Zeitschrijifur Naturforschung, B31, 554-557. 

8 Daniel, M. C., Astruc, D., Gold nanoparticles Assembly, supramolecular chemistry, quantum-size-related properties, and applications toward biology, catalysis, and nanotechnology , Chem. Rev. 2004, 104, 293-346. 

Coinage metal nanoparticles (Au, Ag and Cu) have been particularly popular in nanoparticle research because of their easy synthesis, the high intensity of their surface plasmon band and the ease of functionalising the metal surface with ligands such as thiolates. Gold nanoparticles are prepared 

Dendritic ferrocenyl amide-derived nanoparticles have been nsed as chemiresistor sensors for the detection of volatile organic componnds. 

Surfyeo cKpiisurc lo suspertsion of rccepior-iagged nanopariicles 

Liu et al. established a colorimetric sensing strategy for dihydronicotinamide adenine dinucleotide (NADH, 34). When 4-mercaptophenylboronic acid (MPBA) is introduced on the surface of AuNPs through Au-S interaction. 

Formation process of gold nanoparticles in the presence of PVA. Reprinted from ref. 38, Copyright 2005, with permission from Elsevier. 

MPBA in the presence of different NADH concentrations (a) 0, (b) 50 nM, (c) 500 nM, (d) 1 pM, (e) 2 pM, (f) 4 pM, (g) 6 pM, and (h) 8 pM (B) the corresponding UV-vis adsorption spectra and (C) the linear dependence of the A520M630 on the NADH concentration. All data were average of three replicable determinations. Reprinted from ref. 39, Copyright 2012, with permission from Elsevier. 

Wu et al. demonstrated that metal nanoparticles can be immobilized in stimuli-responsive microgels, and this system offers the possibilities of external switching and manipulation of sensor devices. The CdS hybrid microgels were synthesized through the in situ formation of CdS QDs in the interior of the copolymer microgel of poly(N-isopropylacrylamide-acrylamide-acrylamidophenylboronic acid) [p(NIPAM-AAm-PBA)]. It was 

---

Figure C2.17.13. A model calculation of the optical absorjDtion of gold nanocrystals. The fonnalism outlined in the text is used to calculate the absorjDtion cross section of bulk gold (solid curve) and of gold nanoparticles of 3 mn (long dashes), 2 mn (short dashes) and 1 mn (dots) radius. The bulk dielectric properties are obtained from a cubic spline fit to the data of [237]. The small blue shift and substantial broadening which result from the mean free path limitation are...

Link S and El-Sayed M A 1999 Size and temperature dependence of the plasmon absorption of colloidal gold nanoparticles J. Phys. Chem. B 103 4212... 

Nanotechnology has led to very efficient versions of liposomes. Tiny hollow spheres only nanometers in diameter hold even tinier capsules of medicine. The spheres are made of silica covered with gold nanoparticles and when they are coated with antibodies they attach to tumor cells. The spheres are sensitive to light of specific wavelengths and when the light is applied, either heat up and destroy the tumor, or burst, releasing the drugs within the capsules directly into the tumor. 

Figure 42 Stabilization of gold nanoparticles using T8[(CH2)3NH3Cl]8.

Prasad, B. L. V. Stoeva, S. 1. Sorensen, C. M. and Klabimde, K J. (2002). Digestive Ripening of Thiolated Gold Nanoparticles The Effect of Alkyl Chain Length. Langmuir, 28, 7515-7520. 

Youk J.H., Park M.K., Locklin J., Advincula R., Yang J., and Mays J. Preparation of aggregation stable gold nanoparticles using star-block copolymers, Langmuir, 18, 2455, 2002. 

Louis, C. (2007) Gold nanoparticles Recent advances in CO oxidation. Chapter 15, in Nanoparticles and Catalysis (ed. 

Fig. 35 TEM image of peptide fibres coated with streptavidin-gold nanoparticles, (a, b) Peptides with biotin directly attached (using SAF-pl-biotin) particles are 10 nm, (c) Peptide fibre with biotinylated anti-FLAG antibody attached that was then bound to gold-labelled streptavidin particles are 5 nm. Reprinted with permission from Ryadnov and Woolfson [76]. Copyright 2004 American Chemical Society...

Inspired by the elastin-based side-chain polymers, Lemieux et al. prepared elastin-based stimulus-responsive gold nanoparticles. To this end, they capped gold particles with a layer of a single repeat of thiol-functionalized VPGVG peptides (Fig. 17a). These nanoparticles showed LCST behavior, which was modulated by varying the pH of the solution [131]. 

Fig. 17 (a) Elastin-based stimulus-responsive gold nanoparticles. Reproduced from [131] by permission of The Royal Society of Chemistry (b) Functionalization of a glass surface with ELP. In the first step, the glass surface is aminosilylated with N-2-(aminoethyl)-3-aminopropyl-trimethoxysilane, then modified with glutaraldehyde. Subsequently, the stimulus-responsive biopolymer is covalently immobilized using reductive amination. Reproduced from [132] by permission of The Royal Society of Chemistry... 

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... 

However, the main research result from those years was the discovery of the room-temperature single-electron phenomenon. In the 1990s, STM experiments on liquid crystal had shown a very weak staircase (Nejoh 1991) only one year later, the clear observations of the coulomb blockade and the coulomb staircase were demonstrated on gold nanoparticles (Shonenberger et al. 1992a) and the role of system symmetry on the appearance of these two phenomena was outlined (Shonenberger et al. 1992b). 

Photodissociation of Diiodoethane Hydrodynamics of Laser-Heated Liquids Gold Nanoparticles in Water... 

A second problem in these studies concerns cavitation dynamics on the nanometer length scale [86]. If sufficiently energetic, the ultrafast laser excitation of a gold nanoparticle causes strong nonequilibrium heating of the particle lattice and of the water shell close to the particle surface. Above a threshold in the laser power, which defines the onset of homogeneous nucleation, nanoscale water bubbles develop around the particles, expand, and collapse again within the first nanosecond after excitation (Fig. 9). The size of the bubbles may be examined in this way. 

The last problem of this series concerns femtosecond laser ablation from gold nanoparticles [87]. In this process, solid material transforms into a volatile phase initiated by rapid deposition of energy. This ablation is nonthermal in nature. Material ejection is induced by the enhancement of the electric field close to the curved nanoparticle surface. This ablation is achievable for laser excitation powers far below the onset of general catastrophic material deterioration, such as plasma formation or laser-induced explosive boiling. Anisotropy in the ablation pattern was observed. It coincides with a reduction of the surface barrier from water vaporization and particle melting. This effect limits any high-power manipulation of nanostructured surfaces such as surface-enhanced Raman measurements or plasmonics with femtosecond pulses. 

A. Plech, V. Kotaidis, S. Gresillon, C. Dahmen, and G. von Plessen, Laser-induced heating and melting of gold nanoparticles studied by time-resolved X-ray scattering. Phy. Rev. B 70(19), 195423 (2004). 

A. Plech, V. Kotaidis, M. Lorenc, and J. Boneberg, Femtosecond laser near-field ablation from gold nanoparticles. Nature Phys. 2, 44-47 (2006). 

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. 

Scheme 6. A highly sensitive detection method using an antibody specific for IgG (Fc) and gold nanoparticle...

Gold nanoparticles and gold(lll) complexes as general and selective hydrosilylation catalysts. Angewandte Chemie International Edition, 46, 7820. 

Mendez-Villuendas, E. and Bowles, R.K. (2007) Surface Nucleation in the Freezing of Gold Nanoparticles. Physical Review Letters, 98, 185503-1-185503-4. 

---