Scheme 1. Synthetic scheme of Pd catalyst formed with different peptide template amounts. The top pathway reveals the fabrication of Pd catalysts with low Pd/peptide ratios, while the bottom pathway indicates the preparation of Pd catalysts with high Pd/peptide ratios. In this scheme, the green spheres represent Pd²⁺ ions that interact with the peptide template, which are then reduced to Pd metallic nanoparticles. This scheme is reprinted with permission from ref. 38, copyright American Chemistry Society.