Researchers at the Institute of Science Tokyo and the University of Leeds published a study on August 18, 2026, in Advanced Functional Materials demonstrating that positioning biomineralization peptides inside liposomal nanoreactors allows scientists to control the size and shape of growing gold nanoparticles.
Controlling how gold nanoparticles form remains a persistent challenge for materials scientists, particularly under mild and environmentally friendly conditions. Because gold nanoparticles possess unique optical and chemical properties owing to their size and shape, precise synthesis is vital for advanced technologies like sensing, catalysis, and imaging. A research team tackled this hurdle by looking closely at biomineralization peptides—short chains of amino acids capable of promoting metal reduction and directing nanoparticle growth.
Liposomal Nanoreactors and Peptide Positioning at the Membrane Interface
To investigate how spatial organization alters nanoparticle formation, the researchers used liposomes as confined nanoscale reaction compartments and introduced a gold precursor, HAuCl4. Led by Associate Professor Masayoshi Tanaka from the Institute of Science Tokyo alongside Graduate Student Yuya Abe and Professor Stephen D. Evans from the University of Leeds, the team examined the behavior of a specific peptide known as B3.
When B3 was deployed, it predominantly localized near the liposome membrane. Transmission electron microscopy and elemental mapping revealed that this membrane-adjacent positioning produced highly branched, anisotropic gold and liposome complexes. Gold concentrated heavily toward the periphery of these structures, confirming that nanoparticle growth occurred close to the membrane interface.
Shifting Synthesis Toward Aqueous Interiors With Cationic Lipids
The research team then altered the chemistry of the liposomes by introducing the cationic lipid DOTAP. This adjustment shifted the B3 peptide away from the membrane and toward the aqueous interior of the liposome. That spatial relocation changed the morphological outcome, replacing the highly branched structures with spherical gold nanoparticles.
To understand the limits of this control, the researchers tested a second biomineralization peptide named G1. Unlike B3, G1 remained predominantly localized within the aqueous interior regardless of whether the membrane composition was altered. This internal confinement yielded small, nearly spherical gold nanoparticles with an average diameter of about 2.7 nanometers.
Design Strategies for Bio-Inspired Nanomaterials
The comparative experiments demonstrate that nanoparticle morphology depends on a combination of peptide sequence specificity and how that peptide organizes spatially within a confined reaction environment. By managing both sequence design and membrane composition, materials scientists gain a new mechanism to dictate how chemical reactions unfold across nanoscale compartments.
This approach provides a new design strategy for bio-inspired nanomaterials, offering researchers a way to steer nanoparticle growth toward specific structures with tailored properties and potential functions.