Ultrashort Peptides as Stabilizing Agents for Colloidal Nanogold

Ultrashort peptides hold immense potential as structural tools for enhancing the colloidal stability of nanomaterials, such as nanogold. However, such applications have been largely unexplored in part due to the inherent complexity in designing, synthesizing, and testing short peptides as colloidal nanoparticle stabilizers. In this work, we use a motif-function-guided process for peptide synthesis and high throughput screening to evaluate the colloidal stability of spherical nanogold solutions and pentapeptides. We have successfully built a library of peptides capable of stabilizing colloidal nanogold at peptide concentrations of ≤1.0 μM. This represents a 50–100-fold reduction in the concentration required for stability compared to other small molecules used as capping agents, which illustrates the potential of using short peptide sequences as colloidal nanogold stabilizers. Our findings could significantly impact the future development of high-affinity surface modifiers for the custom engineering of nanogold by providing a deeper understanding of the complex interactions between nanoparticles and peptides.