title: Light-operated mechanized nanoparticles.
abstract: Mesoporous silica (MCM-41) nanoparticles modified by azobenzene derivatives, capable of storing small molecules and releasing them following light irradiation, have been fabricated and characterized. In the presence of the beta-cyclodextrin and/or pyrene-modified beta-cyclodextrin rings, the beta-cyclodextrin and/or pyrene-modified beta-cyclodextrin rings will thread onto the azobenzene-containing stalks and bind to trans-azobenzene units to form the pseudorotaxanes, thus sealing the nanopores and stopping release of the cargo. Upon irradiation, the isomerization of trans-to-cis azobenzene units leads to the dissociation of the beta-cyclodextrin and/or pyrene-modified beta-cyclodextrin rings from the stalks, thus opening the gates to the nanopores and releasing the cargo.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, 405 Hilgard Avenue, Los Angeles, California 90095-1569, USA.
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Ferris
authors.forename: Yan-Li
authors.initials: YL
authors.lastname: Zhao
authors.forename: Niveen M
authors.initials: NM
authors.lastname: Khashab
authors.forename: Hussam A
authors.initials: HA
authors.lastname: Khatib
authors.forename: J Fraser
authors.initials: JF
authors.lastname: Stoddart
authors.forename: Jeffrey I
authors.initials: JI
authors.lastname: Zink
mesh_terms: D001391:Azo Compounds / Q000737:chemistry*; D003692:Delayed-Action Preparations; D008027:Light; D008163:Luminescent Measurements; D008958:Models, Molecular; D053758:Nanoparticles / Q000737:chemistry*; D055668:Photochemical Processes; D011721:Pyrenes / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D001391:Azo Compounds; D003692:Delayed-Action Preparations; C509968:MCM-41; D011721:Pyrenes; D047392:beta-Cyclodextrins; D012822:Silicon Dioxide; C009850:azobenzene; C031215:betadex