Protein-Metal Interactions Probed by SERS: Lysozyme on Nanostructured Gold Surface

Surface-enhanced Raman scattering is a well-established technique for molecular detection at low concentration, which is becoming increasingly popular in the field of biotechnology and health sciences. Since the process is understood in depth, the technique is becoming reliable. In this contribution, we consider another aspect of SERS besides molecular detection, focusing on the binding mechanisms of a complex system such as a protein to the noble metal substrates required by the technique itself. We also show that using a solid nanostructured substrate produced by controlled pulsed laser deposition SERS enables label-free detection of a protein. This is checked on lysozyme as a well-known prototype. Use of solid substrates with controlled morphology proves advantageous over colloidal systems for SERS applications. Moreover, such substrates are superior in terms of shelf life, packaging and ease of shipment.