b2815 Tissue Engineering and Nanotheranostics “9.61x6.69”126 Tissue Engineering and Nanotheranostics
AgNPs. This technique has been utilized to synthesize Ag–FePtNPs
and other Ag-based hybrid structures.^93 Some of them are demon-
strated in Fig. 18.
Another interesting and complex category of Janus nanoparticles
are the ternary dumbbell nanostructures which have been fabricated
by seed-mediated growth. In this kind of particles, the third domain
was attached by over growth of the desired particle, e.g. Sun et al.
presented a concept of “tug-of-War” in nanoparticles.^94 In synthetic
processes, Au 2 NPs are additionally grown-onto Au 1 –Fe 3 O 4 dumbbell
hybrid structures for the synthesis of ternary Au–Au–Fe 3 O 4 or Au–
Fe 3 O 4 –Au NPs. The viable growth of Au 2 NPs on Au1 surface in the
Au–Fe 3 O 4 seeds produced a “tug of war” between Fe 3 O 4 and Au 2 in
the Fe 3 O 4 –Au 1 –Au 2 ternary nanostructures resulting Au 2 extorted
Au 1 from the Au 1 –Fe 3 O 4 structure to developed Au 2 –Au 1 –Fe 3 O 4 ter-
nary binary magnetic nanohybrids. In another study, Fe 3 O 4 –Au–
Fe 3 O 4 ternary magnetic–plasmonic nanohybrids were attained by
fusing and absorption of the AuNPs from two Au–Fe 3 O 4 nanocom-
posites.^95 The graphical mechanism is given in Fig. 19(a). The corre-
sponding TEM images are also shown in Fig. 19(b).
Fig. 17. (a) Schematic illustration of the fabrication of Au–(Fe 3 O 4 @SiO 2 ) Janus
structure in the presence of alkanethiol and ammonia solution. TEM pictures of
(b) OAm-cotaed AuNPs, (c) hydrophobic Au–Fe 3 O 4 dumbbell-like structure and
(d) Au-(Fe 3 O 4 @SiO 2 ) nanoparticles. Reprinted with permission from Ref. 89.^