Sensitizing of pyrene fluorescence by β-cyclodextrin-modified TiO2 nanoparticles.
TiO(2) nanoparticles were synthesized by hydrolysis of tetraisopropyl orthotitanate in an aqueous solution of cyclodextrin. The β-cyclodextrin-modified spherical TiO(2) nanoparticles were water-dispersible and had an average particle diameter of 4.4 ± 1 nm. Pyrene fluorescence was enhanced by increasing the concentration of β-cyclodextrin-modified TiO(2) nanoparticle and the sensitization effect was triply stronger than the case of the β-cyclodextrin only. The increase in a concentration of host (β-cyclodextrin) changes its microenvironment for guest (pyrene), that is, the interaction of pyrene with apolar cavity of β-cyclodextrin increases, resulting in enhancement of fluorescence. The sensitization behavior of pyrene fluorescence in the presence of TiO(2) nanoparticles occurs from the increase in the extinction coefficient of pyrene, demonstrating the charge transfer between pyrene and metal oxide nanoparticle.
Shown
Indrajit
I
Graduate Institute of Engineering, National Taiwan University of Science and Technology, 43 Keelung Road, Section 4, Taipei 106-07, Taiwan.
Ujihara
Masaki
M
Imae
Toyoko
T
D005453:Fluorescence; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D011721:Pyrenes / Q000737:chemistry*; D012996:Solutions; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*; D014867:Water / Q000737:chemistry; D047392:beta-Cyclodextrins / Q000737:chemistry*
D011721:Pyrenes; D012996:Solutions; D047392:beta-Cyclodextrins; D014867:Water; C009495:titanium dioxide; C030984:pyrene; D014025:Titanium; C031215:betadex