Negatively
charged liposomes accomplished both functions as a reducing
and stabilizing agent in the synthesis of gold nanotriangles (GNTs).
Liposomes are based on a mixture of phospholipids phosphatidylcholine/phosphoglycerol,
and they were used as a template phase to perform the GNTs. The method
was evaluated under different conditions such as temperature, reaction
time, phosphoglycerol chain length, and precursor concentration. Isotropic
and anisotropic gold nanoparticles are formed simultaneously during
the synthesis. Therefore, by combining centrifugation and depletion
flocculation strategies, the sample was concentrated in terms of GNTs
from 15% crude to 80% by using sodium dodecyl sulfate (SDS). As a
result, a green colored dispersion was obtained containing highly
purified, well-defined, negatively charged GNTs, where the edge length
of most particles is centered in the range of 60–80 nm with
an average thickness of 7.8 ± 0.1 nm. By this purification process,
it was possible to highly increase the yield in terms of GNTs. Other
surfactants [cetyltrimethylammonium chloride (CTAC), hexadecyltrimethylammonium
bromide (CTAB), Tween 20, and dodecyldimethylammonium bromide] were
evaluated during the purification stage, and both CTAB and CTAC show
similar results to those obtained by using SDS. These GNTs are potential
candidates for future applications in molecular imaging, photothermal
therapy, drug delivery, biosensing, and photodynamic therapy.