Effective ACE2 peptide-nanoparticle conjugation and its binding with the SARS-Cov-2 RBD quantified by dynamic light scattering.

The infection of coronavirus initiates with the binding between its spike protein receptor binding domain (RBD) and a human cellular receptor called angiotensin-converting enzyme 2 (ACE2). Here, we construct truncated ACE2 peptide-conjugated gold nanoparticles as antiviral scaffolds and study their binding with the SARS-CoV-2 RBD using dynamic light scattering (DLS). Systematic DLS analysis identifies the effective peptide-nanoparticle conjugation and its efficient, specific, and long-lasting multivalent binding towards the RBD with a binding affinity of 41 nM, indicating the potential of this antiviral platform to compete with natural ACE2-RBD interactions for viral blocking and showcasing an accessible approach to measure the binding constants and kinetics.