Stable and brightly luminescent amine-terminated Si nanoparticles (SiNPs) have been synt
hesized from electroc
hemically etc
hed porous silicon (PSi). T
he surface amine termination was confirmed by FTIR, NMR, and XPS studies. T
he mean diameter of t
he crystal core of 4.6 nm was measured by transmission electron microscopy (TEM), which is in a good agreement with t
he size obtained by dynamic light scattering (DLS). T
he dry, amine-terminated product can be obtained from bulk silicon wafers in less than 4 h. This represents a significant improvement over similar routines using PSi w
here times of >10 h are common. T
he emission quantum yield was found to be about 22% and t
he nanoparticles exhibited an exceptional stability over a wide pH range (4鈥?4). T
hey are resistant to aging over several weeks. T
he amine-terminated SiNPs showed no significant cytotoxic effects toward HepG2 cells, as assessed with MTT assays.
Keywords:
cellular imaging; semiconductor nanoparticles; surface capping; photoelectron spectroscopy; FTIR; NMR