title: Nanovalve-controlled cargo release activated by plasmonic heating.
abstract: The synthesis and operation of a light-operated nanovalve that controls the pore openings of mesoporous silica nanoparticles containing gold nanoparticle cores is described. The nanoparticles, consisting of 20 nm gold cores inside ~150 nm mesoporous silica spheres, were synthesized using a unique one-pot method. The nanovalves consist of cucurbit[6]uril rings encircling stalks that are attached to the ~2 nm pore openings. Plasmonic heating of the gold core raises the local temperature and decreases the ring-stalk binding constant, thereby unblocking the pore and releasing the cargo molecules that were preloaded inside. Bulk heating of the suspended particles to 60 °C is required to release the cargo, but no bulk temperature change was observed in the plasmonic heating release experiment. High-intensity irradiation caused thermal damage to the silica particles, but low-intensity illumination caused a local temperature increase sufficient to operate the valves without damaging the nanoparticle containers. These light-stimulated, thermally activated, mechanized nanoparticles represent a new system with potential utility for on-command drug release.
authors.affiliation: Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095, USA.
authors.forename: Jonas
authors.initials: J
authors.lastname: Croissant
authors.forename: Jeffrey I
authors.initials: JI
authors.lastname: Zink
mesh_terms: D001952:Bridged-Ring Compounds / Q000737:chemistry; D003692:Delayed-Action Preparations / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006361:Heating; D007093:Imidazoles / Q000737:chemistry; D008027:Light; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D012822:Silicon Dioxide / Q000737:chemistry*; D047028:Macrocyclic Compounds; D000099246:Cucurbit(n)urils
chemical_list: D001952:Bridged-Ring Compounds; D003692:Delayed-Action Preparations; D006046:Gold; D007093:Imidazoles; D012822:Silicon Dioxide; C454805:cucurbit(6)uril; D047028:Macrocyclic Compounds; D000099246:Cucurbit(n)urils