Co-assembled gold nanorod@tripeptide core-shell nanospheres for aqueous Hg²⁺ removal

The construction of peptide and metal nanoparticles hybrid is attractive to explore their synergistic properties and applications extensively. However, it remains a challenge to fabricate a well-defined and size-controllable short peptide/Au nanoparticles hybrid. Here, we report a facile and flexible co-assembly strategy for the construction of tripeptide coated Au nanorods (AuNRs). The tripeptide (Phe-Phe-Cys, FFC) grows via covalently crosslinking to form spheres. The size of the core@shell nanospheres can be controlled by modulating the amount or size of AuNRs. Especially, the concentration of AuNRs fixes the amount of seeds, which further affect the local concentration of FFC on the surface of AuNRs seed, leading to a narrower diameter of hybrid compared to FFC spheres. Moreover, owing to their synergistic effects, this hybrid exhibits a good adsorption capacity of Hg²⁺ from aqueous solutions by electrostatic interaction and forming into Au/Hg amalgam. This strategy could be extended to the fabrication of other biomolecules and metal nanoparticle hybrids with diverse functions.