Playing “Nano -Lego ”: VNPs as Building Blocks for the Construction of Multi -Dimensional Arrays - Viral Nanoparticles: Tools for Materials Science and Biomedicine - page 186

Figure 7.14 Top panel: (a) Schematic of Ni(II) chelation reaction with NTA alkanethiol

molecules bound to Au surfaces leading to reversible binding of His-CPMV to NTA-
terminated regions and of molecular “inks” used for nanografting process. Short,
PEG-terminated alkanethiol resists binding of CPMV (green headgroup); longer,
NTA-terminated alkanethiol provides a reversible metal complex linkage to His tags
engineered into CPMV (red headgroup). (b) Schematic of nanografting and virus
deposition process

AFM images showing evolution of coverage
and order during His-CPMV adsorption as the virus flux [i.e., virus concentration
(

. Bottom panel: in situ

C
V

)] and inter-viral interaction (i.e., PEG concentration) are increased. At low flux

( = 0.2 mg/ml) and 0% PEG (w/w) (a), His-CPMV attaches almost exclusively

to Ni-NTA lines, but with poor coverage. At higher flux (

C
V

= 2 mg/ml) and weak
interaction (0% PEG) (b), virions still attach to the Ni-NTA lines, but the lines are
fully covered. As the inter-viral interaction is increased [

C

V

C = 0.5 mg/ml, 1 wt PEG

V

for (c) and = 2 mg/ml, 1 wt% PEG for (d)], virus assembly spreads outward from

the lines to give stripes that are multiple virions in width and clusters lying between
the lines. (e) Higher-resolution AFM image of condition (b) showing the single line
of His-CPMV particles. (f ) High-resolution image of condition (d) showing a packing
geometry similar to that seen for the ordered virus cluster in Fig. 1e. Times at
which images were collected are (a) 4, (b) 8, (c) 4, and (d) 6 h. Reproduced with
permission from Cheung, C. L., Chung, S. W., Chatterji, A., Lin, T., Johnson, J. E., Hok,
S., Perkins, J., De Yoreo, J. J. (2006) Physical controls on directed virus assembly at
nanoscale chemical templates,

C

V

J. Am. Chem. Soc. , 128 (33), 10801-10807.