VNPs as Templates for Materials Synthesis - Viral Nanoparticles: Tools for Materials Science and Biomedicine - page 152

pH conditions have to be carefully selected and adjusted. Using EDL, silver,
nickel, cobalt, and copper have been deposited on the exterior or interior
of TMV (some examples are given in Fig. 6.7) (Balci et al ., 2006; Knez et al .,

2002, 2003, 2004).
ALD is mainly used in the microelectronics industry. The ALD process is
as follows:
Step 1: The

(here TMV) is dried onto a solid support and transferred
to the ALD chamber.
Step 2: The target is exposed to a precursor molecule from a gas phase, and
the precursors form a layer on the target.
Step 3: The ALD chamber is purged to remove any excess precursor gas.
Step 4: The target is exposed to a second precursor that reacts with the first
precursor to give the desired product. The cycle can be repeated
until the desired layer thickness is achieved.
ALD has been applied to TMV to yield aluminum oxide and titanium oxide
nanostructures. The interior and exterior surfaces of TMV were coated with
the mineral; the exterior coating can be removed by ultrasonication to obtain

target

Figure Transmission electron micrographs and accompanying energy

dispersive X-ray spectra of (a) Au on thick-shell silica-coated TMV template, (b) Ag
on thick-shell silica-coated TMV template, (c) Pt on thick-shell silica-coated TMV
template, (d) Pd on thick-shell silica-coated TMV template. Al, Fe, and Cu peaks in
the EDS spectra are caused by background effects. Scale bar is equal to 100 nm.
Reproduced with permission from Royston, E. S., Brown, A. D., Harris, M. T., and
Culver, J. N. (2009) Preparation of silica stabilized

6.8

Tobacco mosaic virus templates for

the production of metal and layered nanoparticles, J. Colloid Interface Sci. , 332 (2),

402-407.