Surface plasmon resonance enhanced scattering of Au colloidal nanoparticles

Suspended gold nanoparticles have been synthesized via electrochemical method. The strongest resonance scattering peak is at 485 nm, which results from the surface plasmon resonance. When the excited wavelength is at 242 nm (12.4 × 10¹⁴ Hz), there have been a 1/2 fraction frequency scattering peak at 485 nm (1/2 × 12.4 × 10¹⁴ Hz) and a 1/3 fraction frequency scattering peak at 726 nm (1/3 × 12.4 × 10¹⁴ Hz) displayed. Emission spectra with different particle diameters were compared, the intensity of scattering light increases with the particle size. The frequency-dependent scattering average cross section of small particle was calculated from Mie theory. The model calculation is in agreement with the experimental results.