Metal-Free Peptide Semiconductor-Enhanced Raman Scattering

There is a growing\ndemand for sustainable and safe materials in\ndeveloping technological systems and devices, including those that\nenhance Raman scattering. Organic (bio) materials based on simple\npeptides are one class of such materials. This study investigates\nself-assembled semiconducting peptides as metal-free substrates for\nsurface-enhanced Raman scattering. Our results reveal significant\nvariations in Raman enhancement factors, spanning up to 2 orders of\nmagnitude. We examined specific Raman enhancement selection rules\nrelated to the energy levels and structural configurations of the\nprobe molecules. The effectiveness of these rules underscores the\nimportance of strong molecule-peptide coupling and efficient charge\ntransfer for achieving optimal Raman enhancement factors. These insights\noffer a foundational understanding of peptide–molecule interactions\nand the underlying chemical mechanisms driving Raman enhancement,\nhighlighting the potential of organic semiconductor-based materials\nas highly effective platforms for enhancing Raman scattering in chemical\nsensing applications.