Synthesis of metallic nanoshells on porphyrin-stabilized emulsions

A method for making metal nanoshells, the method comprising:

• forming an emulsion comprising lipoporphyrin-stabilized nanodroplets, wherein the emulsion comprises a photocatalytic lipoporphyrin, water, and an organic liquid wherein a concentration of the organic liquid is less than or equal to approximately an order of magnitude greater than a solubility limit of the organic liquid in water and wherein a solubility of the photocatalytic lipoporphyrin in water and a solubility of the photocatalytic lipoporphyrin in the organic liquid are sufficient to position the photocatalytic lipoporphyrin at a water/organic liquid interface of the lipoporphyrin-stabilized nanodroplets;
• adding a seed metal ion and an electron donor species to the emulsion;
• illuminating the emulsion with light of a wavelength that causes electronic excitation of the photocatalytic lipoporphyrin to form an excited photocatalytic lipoporphyrin;
• reacting the excited photocatalytic lipoporphyrin with the electron donor species to form a reduced photocatalytic lipoporphyrin
• reducing the seed metal ion by reaction with the reduced photocatalytic lipoporphyrin to form a seed metal nanoparticle at the water/organic liquid interface;
• adding a shell metal ion to the emulsion;
• and
• reducing the shell metal ion catalytically using the seed metal nanoparticle to form a metallic nanoshell.