Platinu
m-catalyzed hydrosilylation of hydrogen-ter
minated silicon nanoparticles (Si NPs) with 2,2,2-trifluoroethyl 4-pentenoate gave well-defined nanoparticles (NPs) with surface groups that are reactive toward a
mines. The particles showed a dia
meter of 1.4 卤 0.2 n
m as revealed by trans
mission electron
microscopy (TEM)
measure
ments. Characterization with
1H,
13C and heteronuclear NMR techniques revealed that the trifluoroethyl pentenoate group is attached to the Si NP surface via the ter
minal carbon ato
m. The trifluoroethyl ester is reactive toward pri
mary a
mines, allowing for additional surface functionalization. Modification of the Si NPs was perfor
med with benzyla
mine, 1,2-dia
minoethane, and propargyla
mine. The
modification gave a co
mplete substitution of the trifluoroethyl group to a
mide groups. The
modified Si NPs were characterized in detail by a series of one-di
mensional (1-D) and two-di
mensional (2-D) NMR techniques and by FT-IR. The propargyla
mide-ter
minated Si NPs were further functionalized with an azide-ter
minated fluorescent dye (Azide-Fluor 585 sulphorhoda
mine) using a copper-catalyzed azide-alkyne cycloaddition reaction (CuAAC). Gel per
meation chro
matography and ti
me-resolved fluorescence anisotropy spectroscopy of the dye reveal a significant increase in the hydrodyna
mic radius upon clicking of the dye. Additionally, NMR spectroscopy reveals the presence of a 1,2,3-triazole ring in the product, which confir
ms that the increase in the hydrodyna
mic radius is caused by the attach
ment of the dye to the Si NP surface via the CuAAC reaction.
Keywords:
silicon; nanoparticles; bioconjugation; NMR; mistry&qsSearchArea=searchText">click chemistry