Polyelectrolyte wrapping layers control rates of photothermal molecular release from gold nanorods

Gold nanorods show great promise as light-controlled molecular release systems. Dye molecules were loaded within a variable number of polyelectrolyte multilayers wrapped around gold nanorods. The dye photoinduced release rate depended on the quantity and type of polyelectrolyte trapping layers and could be tuned by a factor of 100. Only two molecular capping layers were sufficient to turn off release. Comparison of the phototriggered molecular release rate to a pure thermal experiment provides an estimate of the effective temperature of the nanorod solution upon irradiation.