Capillary electrophoresis of ultrasmall carboxylate functionalized silicon nanoparticles

Capillary electrophoresis is used to separate ultrasmall (∼1 nm) carboxylate functionalized Si nanoparticles (Si-np-COO ^-) prepared via hydrosilylation with an ω-ester 1-alkene. The electropherograms show a monodisperse Si core size with one or two carboxylate groups added to the surface. On-column detection of their laser-induced fluorescence demonstrates that the individual Si-np-COO ^- have narrow emissions (full width at half maximum = 30-40 nm) with a nearly symmetric lineshape. Preparative scale electrophoresis should be a viable route for purification of the Si-np-COO ^- for further study and future applications.