Figure 12.

a) Schematic illustration of the major steps of the production of AuNCs from Ag nanocubes by the galvanic replacement method. (1) Starting reaction; (2) Production of initial hollow nanostructure; (3) Formation of nanoboxes; (4) Dealloying of the Au/Ag nanoboxes; (5) Formation of AuNC-nanobox with pores in the walls; (6) Production of AuNCs. Reprinted with permission from ref. ³⁴⁷ Copyright 2007 Nature Publishing group, b) SEM images (i, ii, iii and iv) (E) of morphological changes in formation of Au NCs: starting from conversion of Ag nanocubes into Au/Ag nanoboxes, and finaly into Au NCs. Reprinted with permission from ref. ³⁵² Copyright 2004 the American Chemical Society, c) Schematic showing synthesis of hollow mesoporous silica NCs and their modification for drug delivery. [CTAB: cetyltrimethylammonium bromide; TEOS: tetraethyl orthosilicate; APTMS: 3-aminopropyltriethoxysilane; PEG: polyethylene glycol; DOX: doxorubicin]. Reprinted with permission from ref. ⁸⁷ Copyright 2011 the Royal Society of Chemistry.