We present a short peptide of only six amino acids that can be used in ambient conditions to simultaneously reduce either Au3+ or Ag+ ions, forming nanoparticles, and function as a stabilizing capping agent. At acidic pH, Hg2+ ions oxidize the silver nanoparticles and Fe2+ ions promote the aggregation of the gold nanoparticles. At alkaline conditions, Mn2+ ions induce the aggregation of the silver nanoparticles. Through the absorbance changes of these processes, these peptide-capped nanoparticles demonstrated a fast, selective, and sensitive pH-dependent detection system. The limit of detection of Hg2+, Mn2+, and Fe2+ was 319 nм, 184 nм, and 320 nм, respectively. Furthermore, the formed gold nanoparticles were successfully enveloped by a silver shell in a peptide-mediated photoreduction process. These bimetallic Au@Ag core/shell nanoparticles were characterized using UV–vis spectroscopy, high-resolution scanning transmission electron microscopy (HR-STEM), and energy dispersive X-ray spectroscopy (EDS). While prior studies used peptides as ligands for nanoparticles, the versatile abilities of the novel peptide presented in this study display the promising potential of using peptides for nanoparticles synthesis. This is because a single peptide can be used in a single-step one-pot synthesis to prepare and stabilize AuNPs, AgNPs, and Au@Ag core/shell nanoparticles, while also allowing to selectively probe different metal ions.
Bibliographical noteFunding Information:
DB acknowledges the Center for Nanoscience and Nanotechnology of the Hebrew University for his Ph.D. fellowship. We would like to thank Dr. Vitaly Gutkin for his help with XPS measurements and Prof. Raed Abu-Reziq for his help with Zeta potential measurements. We would also like to thank Dr. Apurba Pramanik for helpful discussions and input.
© 2022 Elsevier Inc.
- Gold nanoparticles (AuNPs)
- Iron detection
- Manganese detection
- Mercury detection
- Silver nanoparticles (AgNPs)