Biomedical Engineering Reference
In-Depth Information
A
B
C
FIGURE 1.6
6His-SP1-GNP.hybrids.form.protein-GNP.chains.with.different.GNP.separations..(A).Scheme.representing.the.
organization.of.protein-GNP.chains.composed.of.6His-SP1-GNP.hybrids..(B).TEM.image.(phosphotungstic.acid.
staining).of.6His-SP1-GNP.chains.(marked.by.solid.lines)..(C).HAADF-STEM.image.of.6His-SP1-GNP.chains.
with.4.nm.GNP.separation.(vanadium.staining)..From.Medalsy.et.al..2008.
from.the.protein,.which.is.termed.ΔSP1),.thereby.forming.the.variant.6HΔSP1..This.variant.
of.the.SP1.protein.should.have.an.inner.pore.that.may.enable.a.deeper.protrusion.of.the.
GNP.into.the.protein.pore,.as.30.amino.acids.were.deleted.on.each.side.of.the.SP1.ring..As.
expected,.protein-GNP.chains.composed.of.6HΔSP1-GNP.hybrids.have.shorter.inter-GNP.
separations.and.higher.persistence.length.in.comparison.with.the.6His-SP1-GNP.chains.
(Figure 1.7A-C).
Imaging.of.the.6His-SP1-GNP.chains.deposited.on.a.freshly.cleaved.mica.surface.cov-
ered.with.a.~5.nm.thick.layer.of.evaporated.amorphous.carbon.was.performed.using.AFM,.
revealing. the. dimensions. of. the. tubular. chains.. The. carbon. layer. was. obtained. using. a.
standard. carbon. evaporator.. The. carbon. layer. was. added. to. passivate. the. negatively.
charged.mica.surface..Figure 1.8A.reveals.the.expected.height.of.the.tubes,.9-10.nm..The.
A
B
C
3.51 nm
3.82 nm
3.51 nm
3.82 nm
40 nm
20 nm
20 nm
FIGURE 1.7
(A). TEM. image. (Nanovan. staining). of. 6HΔSP1-GNP. chains. with. 3.5. and. 3.8. nm. GNP. separation.. (B. and. C).
Enlargement.of.the.bold.boxes.from.A.(the.arrows.in.B.and.C.point.to.the.adjacent.GNPs)..From.Medalsy.et.al..2008.
