Hollow gold spheres

Hollow gold spheres or core-shell particles consisting of a gold shell on a core of some other material have recently attracted attention. This is because they have interesting and tunable optical extinction properties [56]. These can be readily calculated using Mie theory [57], and there had been some scattered early interest in these shapes as a result [58, 59], but the versatility and properties of these particles only became widely... 

Yin, Y, Erdonmez, C., Aloni, S., and Alivisatos, A. P. [2006] Faceting of nanocrystais during chemical transformation from solid silver spheres to hollow gold octahedra,/ Am. Chem. Soc., 128(39], 12671-12673. 

Figure 3s (a) Collapsed gold-coated RBC disc, (b) A thermally shattered hollow gold disc with a 50-120 nm thick layer of gold, (c) A doublet formed from two thinly coated spheres. 

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. 

Product to be measured 2, fiber optic, which concentrates the light through a safir window on the vial bottom 3, reference fiber optic 4, gold coated hollow sphere, in which the two light bundles are integrated 5, analyzer of the light in the sphere (Fig. I from [1.85]). 

Much more intricate were the items made almost entirely of hair, with just a clasp or fixture of silver or gold. The hair in these delicate pieces could be woven into many shapes such as bows, loops and hollow spheres, and worn as brooches or pendant ear-rings. Another style was a bracelet or necklace made up of narrow ropes of woven hair. 

Lux F, Lerouge F, Bosson J, Lemercier G, Andraud C, Vitrant G, Baldeck PL, Chassagneux F, Parola S (2009) Gold hollow spheres obtained using an innovative emulsion process towards multifunctional Au nanoshells. Nanotechnology 20 355603-355609... 

Fig. 19 Schematic diagram showing the self-assembly of gold and silica nanoparticles into hollow spheres with a two-layer shell structure. Reprinted with permission from [49], copyright (2002) American Chemical Society...

Figure 14.7 TEM ofPANI hollow spheres produced by chemical polymerization of aniline on polystyrene particles and removal with tetrahydrofuran, and decorated with gold nanoparticles. (Reprinted with permission from Langmuir, Polyaniline / Au composite hollow spheres Synthesis, characterisation, and application to the detection of dopamine by X. M. Feng, C.J. Mao, C. Yang et al., 22, 9, 4384-4389. Copyright (2006) American Chemical Society)...

Study, silica-coated gold colloids were encapsulated by PS using MPTMS as silane coupling agent according to the procedure previously described for silica (see Sect. 2.1.1). These particles were subsequently transformed into hollow spheres by chemical etching of the siUca core in acidic medium [326]. 

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