Controlling plasmonic suprastructures through self-assembly of gold nanoparticles with hybrid copolymer-lipid vesicles

Hybrid lipid membranes incorporating amphiphilic copolymers have gained significant attention due to their potential applications in various fields, including drug delivery and sensing. By combining the properties of copolymers and lipid membranes, such as enhanced chemical tunability and stability, environmental responsiveness, and multidomain nature, novel membrane architectures have been proposed. In this study, we investigated the potentialities of hybrid membranes made of two distinct components: the rigid fully saturated phospholipid 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and the soft copolymer poly(butadiene-b-ethyleneoxide) (PBD-b-PEO). The objective was to explore the interaction of citrate-coated gold nanoparticles (AuNPs) and the hybrid membrane, aiming at constructing AuNPs-hybrid vesicles suprastructures with controlled and adjustable plasmonic properties. A series of experimental techniques were employed to investigate hybrid free-standing and supported membranes. The results revealed that the incorporation of the copolymer into the lipid membrane promotes AuNPs clustering, demonstrating a distinctive aggregative phenomenon of citrate-coated AuNPs on multidomain membranes. Importantly, we show that the size and morphology of AuNPs clusters can be precisely controlled in non-homogeneous membranes, enabling the formation of hybrid suprastructures with controlled patch properties. These results highlight the potential of lipid-copolymer hybrid membranes for designing functional materials with tailored plasmonic properties, with potential applications in nanomedicine and sensing.