Laser micromachined SERS substrates in etched fused silica (Conference Presentation)

Silver nanoparticles (Ag-NP) with Surface Enhanced Raman Scattering (SERS) activity were fabricated on a fused silica substrate by ultrafast femtosecond laser photoreduction of a silver salt solution. The SERS effectiveness of the Ag-NP increased with laser writing power and number of scans. SEM images show that the Ag-NP have a more uniform density distribution when using a multi-scan writing technique. A number of different laser parameters were compared, including scan speed, laser power, and number of scans. Overall, it was found that the most effective laser parameters were: 20 µms-1 scan speed, 10 mW laser power and 200 scans. The Ag-NP substrates have been used to detect single bacteria and hold promise to give fast, accurate and specific spectra according to the cell specimen present.