CRYO-TRANSMISSION ELECTRON-MICROSCOPY CONFIRMS CONTROLLED SYNTHESIS OF CADMIUM-SULFIDE NANOCRYSTALS WITHIN LECITHIN VESICLES

Size-quantized CdS nanocrystals of controlled dimensions are synthesiz ed within monodisperse egg lecithin vesicles made by detergent depleti on. Cryo-transmission electron microscopy (cryo-TEM) enables imaging i nsitu both of the vesicle wall and of the encapsulated nanocrystal. Cr yo-TEM images confirm that only one particle per vesicle forms and tha t nanocrystal diameter is determined by the number of Cd2+ ions initia lly encapsulated. These micrographs further show that the particles ad sorb to the inner surface of the vesicle membrane, which suggests that crystal growth and particle core structure could be controlled throug h manipulation of vesicle bilayer chemistry.