Laser-induced shape transformation and electrophoretic analysis of triangular silver nanoplates.

The shape transformation of silver triangular nanoplates induced by nanosecond laser pulses has been monitored using agarose gel electrophoresis as well as optical spectroscopy and electron microscopy. Laser irradiation truncates the vertices of the triangular nanoplates, having an average edge size of 110 nm and an average thickness of 14 nm, to form nearly regular-hexagonal and spherical silver nanoplates gradually. The surface-enhanced Raman scattering of 4-nitrobenzenethiol absorbed on silver nanoparticles has been found to decrease enormously with laser irradiation, showing its strong dependence on the shape transformation of nanostructures. Electrophoretic mobility values have been found to decrease substantially with the increase of irradiation time, indicating that the surface charge density of silver nanoplates has been modified largely by laser pulses.