Tissue Engineering And Nanotheranostics

“9.61x6.69” b2815 Tissue Engineering and Nanotheranostics

Plasmonic Nanoparticles Application in Biosensor and Bioimaging 165

seeds to anisotropically grow into nanorods and nanobars, respec­

tively.^91 The single twinned seeds produce right bipyramids or nano­

beams with a truncated and ultimately sharp morphology.^77 Besides,

multiply twinned seeds grow into rods or nanowires with a pentago­

nal cross­section directly. In general, cubes, bipyramids, and pentago­

nal wires are usually prepared by polyol process. In order to improve

the purity of production, a number of ways, such as oxidative etching,

have been investigated. Oxidative etching removes multiply twinned

Fig. 2. A schematic illustrating the reaction pathways that lead to AuNPs having
different shapes. First, a precursor is reduced or decomposed to form nuclei (small
clusters). Once the nuclei have grown past a certain size, they become seeds with a
single­crystal, singly twinned, or multiply twinned structures. Twin planes are deline­
ated in the drawing with blue lines. Figure modified with permission from Ref. 90.
Copyright 2011, American Chemical Society.