Enlighted: Silver Nanoparticles Undergo Photoinduced Shape Transformations and Are Photostable When Coated with Hybrid Lipid Membranes

Producing silver nanoparticles (AgNPs) of homogeneous shapes and sizes that are stable for oxidation remains challenging. Here, a fast and accessible synthesis is presented to tune the homogeneity of triangular plates (AgNPLs) using light. This study showed AgNPs of varying shapes (spheres, rounded triangles, and rods), sizes (10–20, 40, and 33 nm, respectively), and surface chemistry (citrate and PVP capping agents) undergo a light-induced conversion to 75–85% sharp AgNPLs with a narrow-localized surface plasmon resonance (LSPR) band with λ_max at 680 nm and an average edge length of 40 nm ± 5.6 nm as confirmed by UV–vis spectroscopy and transmission electron microscopy (TEM), respectively. Further exploration into the mechanism confirmed that Ag⁺ ions, O₂, and light are critical parameters for the light-induced transformation of AgNSs to AgNPLs. Under an inert atmosphere, shape transformation is inhibited, reinforcing the essential role of O₂ in the process. More remarkably, when AgNPs of any size or shape are coated with a hybrid lipid-coated membrane, the AgNPs had exceptional photostability, showing no change LSPR band, underscoring their resistance to photooxidation and shape transformation even in the presence of excess Ag⁺ ions, O₂, and AgNSs. The results highlight the importance of light in tuning the homogeneity of AgNPs and the superior stabilizing effect of hybrid lipid membranes.