Laser-treated substrate with nanoparticles for surface-enhanced Raman scattering

A rapid and simple approach to fabricate a large area of nanostructured substrate for surface-enhanced Raman scattering (SERS) is reported. Gold nanoparticles ranging from 10to40 nm in diameter uniformly distributed on a silicon substrate were obtained by annealing the gold film precoated on the silicon substrate with UV nanosenond (ns) laser pulses. The gold nanoparticles were formed by surface tension of the melted gold layer heated by ns laser pulses. The enhancement factor of the SERS substrate for Rhodamine 6G at 632.8 nm excitation was measured to be higher than 105. The proposed technique provides the opportunity to equip a functional microchip with SERS capability of high sensitivity and chemical stability.