Controlling Gold Nanoparticle Growth via Peptide Localization in Liposomes
- Controlling the position of biomineralization peptides inside liposomes can steer the growth of gold nanoparticles into either branched structures or spherical particles, according to a study published on...
- Gold nanoparticles possess unique optical and chemical properties that depend heavily on their size and shape.
- Associate Professor Masayoshi Tanaka of the Institute of Science Tokyo led the research team alongside Graduate Student Yuya Abe from the Department of Chemical Science & Engineering and...
Controlling the position of biomineralization peptides inside liposomes can steer the growth of gold nanoparticles into either branched structures or spherical particles, according to a study published on August 18, 2026, in Advanced Functional Materials. Researchers from the Institute of Science Tokyo and the University of Leeds demonstrated that altering peptide localization within nanoscale reaction compartments offers a new strategy for tuning nanoparticle morphology for applications in sensing, catalysis, and imaging.
Controlling Gold Nanoparticle Growth Inside Liposomal Nanoreactors
Gold nanoparticles possess unique optical and chemical properties that depend heavily on their size and shape. However, controlling exact nucleation and growth sites during synthesis remains difficult, especially under mild and environmentally friendly conditions. Short chains of amino acids known as biomineralization peptides can promote metal reduction and direct nanoparticle formation, prompting investigators to test whether positioning these peptides within confined liposome environments could alter growth outcomes.
Leadership and Spatial Organization Strategies
Associate Professor Masayoshi Tanaka of the Institute of Science Tokyo led the research team alongside Graduate Student Yuya Abe from the Department of Chemical Science & Engineering and Professor Stephen D. Evans from the University of Leeds. The team introduced a gold precursor, HAuCl4, into liposomes acting as nanoscale reaction compartments to observe how spatial organization dictates particle morphology.
Membrane Interface Dynamics with the B3 Peptide
The researchers initially examined the peptide B3, which is known to reduce gold ions and influence nanoparticle shape. When utilizing B3, the peptide predominantly localized near the liposome membrane interface, producing highly branched, anisotropic gold-liposome complexes. Transmission electron microscopy and elemental mapping confirmed that gold preferentially concentrated toward the periphery of these structures, indicating that nanoparticle growth occurred right next to the membrane.
Shifting Spatial Confinement with Cationic Lipids
To test whether shifting the peptide changed the outcome, the team added the cationic lipid DOTAP to the liposome composition. This adjustment shifted the B3 peptide toward the aqueous interior of the liposome, yielding spherical gold nanoparticles instead of branched structures. By controlling where the peptide is positioned within the liposome, we can tune the nanoscale reaction environment in which gold nanoparticles grow,
notes Tanaka.
Aqueous Interior Confinement Using Peptide G1
The investigators also tested a second biomineralization peptide named G1. Unlike B3, G1 remained localized within the aqueous interior even after the membrane composition was altered. This spatial confinement produced small, nearly spherical gold nanoparticles with an average diameter of about 2.7 nanometers. The comparison demonstrated that nanoparticle morphology relies both on the specific peptide sequence and on its spatial organization inside the confined reaction environment.