Nanoparticles assemblies on demand: Controlled aggregation of Ag(0) mediated by modified peptoid sequences

Area of Science:

• Materials Science
• Nanotechnology
• Biomaterials

Background:

• Metal nanoparticles (NPs) are crucial for sensing, catalysis, and medicine.
• Controlling NP aggregation for tailored properties remains challenging.
• Biopolymers and oligomers can stabilize and mediate NP assembly.

Purpose of the Study:

• To establish guidelines for controlled silver nanoparticle (Ag(0) NP) aggregation.
• To investigate the influence of peptoid sequence and length on NP assembly.
• To demonstrate control over NP aggregate size and catalytic activity.

Main Methods:

• Utilized N-substituted glycine oligomers (peptoids) as aggregation mediators for Ag(0) NPs.
• Performed experiments at room temperature in water near neutral pH without additives.
• Employed spectroscopic and electron microscopy techniques to analyze NP assemblies.

Main Results:

• Peptoid length and sequence significantly influence Ag(0) NP aggregation.
• Longer peptoids and aromatic side chains promote uniform NP assemblies (average 70nm).
• Short hydrophilic peptoids stabilize well-dispersed Ag(0) NPs.

Conclusions:

• Peptoid properties offer a method for controlled Ag(0) NP assembly.
• Tuning peptoids allows control over aggregate size and catalytic performance.
• Developed guidelines provide a non-trial-and-error approach to NP aggregation.