Immobilization of gold nanoparticles on living cell membranes upon controlled lipid binding

We present a versatile and controlled route to immobilize gold nanoparticles (NPs) on the surface of living cells, while preserving the sensing and optothermal capabilities of the original colloid. Our approach is based on the controlled and selective binding of Au NPs to phospholipids prior to cell incubation. We show that in the presence of the cells the lipid-bound Au NPs are delivered to the cellular membrane and that their diffusion is rather slow and spatially limited, as a result of lipid binding. Avoiding nonspecific membrane labeling, this approach is of general application to several types of colloids and cells and thereby provides a platform for controlled plasmonic and optothermal investigations of living cell membranes.