Biomedical Engineering Reference
In-Depth Information
(
a
)
(
c
)
Au
Au
Au
Au
Au
Au
Au
2
4
6 8 10121416
Energy (keV)
(
d
)
(111)
(200)
(
b
)
(220)
(311)
(222)
30
40
50
60
70
80
90
2 (degree)
(
e
)
22
Au 4f
7/2
20
18
Au 4f
5/2
16
14
12
10
8
6
4
80
82
84
86
88
90
92
Binding Energy (ev)
Figure 11.15
(a.b) SEM images of nanoporous Au networks recorded at various
magniications. (c) EDS spectrum of the synthesized nanoporous Au networks; peak
labeled by an asterisk is attributed to the Ti substrate. (d) XRD spectrum recorded from
the synthesized nanoporous Au network. (e) XPS spectra of the Au 4f region for the
as-synthesized nanoporous Au network. (Reprinted with permission from ref [75])
application in biosensing. Yavuz
et al.
[77] covered the outer shell of
gold nanocages with poly(N-isopropylacrylamide) (pNIPAAm) and its
derivatives. Conformation of the polymer changes in response to small
variations in temperature. With irradiation of a near infrared laser beam
with a wavelength that matches the absorption peak of the Au nanocage,
the metal absorbs the light and converts it into heat leading the poly-
mer chains to collapse. Hence, the ef ectors encapsulated onto the pore
will be released. As soon as the laser is turned of , the polymer returns
to its original extended conformation. h e pores will be closed and the
release of ef ectors will be stopped. Other research groups have also used
nanocages of gold for immobilization of Ab and detection of cancer
biomarkers [78].
