Serial silver clusters biomineralized by one peptide.
Yanyan Cui1, Yaling Wang, Ru Liu
1Lab for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
ACS Nano
|October 26, 2011
Summary
Researchers used a peptide to biomineralize silver (Ag) clusters, producing red and blue emissions. Alkalinity controlled Ag cluster size by influencing peptide structure and ion reduction, impacting optical properties.
Area of Science:
- Biomineralization
- Nanomaterials Science
- Peptide Chemistry
Background:
- Artificial peptides offer novel routes for nanomaterial synthesis.
- Controlling nanoparticle size and optical properties is crucial for applications.
Purpose of the Study:
- To biomineralize silver (Ag) clusters using a specific artificial peptide.
- To investigate the effect of alkaline conditions on Ag cluster formation and optical properties.
Main Methods:
- Biomineralization of Ag clusters using a CCYRGRKKRRQRRR peptide.
- Characterization using UV-visible absorption, infrared spectroscopy, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS).
- Circular dichroism (CD) spectroscopy to analyze peptide secondary structure.
Main Results:
- Peptide-mediated biomineralization yielded Ag clusters with distinct red and blue emissions under varying alkalinity.
- MALDI-TOF MS identified red-emitting clusters as Ag(28) and blue-emitting clusters as Ag(5), Ag(6), and Ag(7).
- Peptide phenol moieties reduced Ag+ ions, while thiol moieties captured formed Ag clusters, with alkalinity controlling reduction potential and cluster size.
Conclusions:
- Alkalinity is a key factor in controlling Ag cluster size and emission color through modulation of peptide reduction potential.
- Peptide secondary structure, influenced by alkalinity, may also play a role in determining Ag cluster size.
- This study demonstrates a peptide-based strategy for tunable synthesis of silver nanoclusters with specific optical properties.
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