title: Interaction of fluorescent sensor with superparamagnetic iron oxide nanoparticles.
abstract: To sense superparamagnetic iron oxides (Fe2O3 and Fe3O4) nanocrystals a sensitive bioactive phenanthroimidazole based fluorescent molecule, 2-(4-fluorophenyl)-1-phenyl-1H-phenanthro [9,10-d] imidazole has been designed and synthesized. Electronic spectral studies show that phenanthroimidazole is bound to the surface of iron oxide semiconductors. Fluorescent enhancement has been explained on the basis of photo-induced electron transfer (PET) mechanism and apparent binding constants have been deduced. Binding of phenanthroimidazole with iron oxide nanoparticles lowers the HOMO and LUMO energy levels of phenanthroimidazole molecule. Chemical affinity between the nitrogen atom of the phenanthroimidazole and Fe(2+) and Fe(3+) ions on the surface of the nano-oxide may result in strong binding of the phenanthroimidazole derivative with the nanoparticles. The electron injection from the photoexcited phenanthroimidazole to the iron oxides conduction band explains the enhanced fluorescence.
authors.affiliation: Department of Chemistry, Annamalai University, Annamalainagar 608 002, Tamil Nadu, India.
authors.forename: Chockalingam
authors.initials: C
authors.lastname: Karunakaran
authors.forename: Jayaraman
authors.initials: J
authors.lastname: Jayabharathi
authors.forename: Ramalingam
authors.initials: R
authors.lastname: Sathishkumar
authors.forename: Karunamoorthy
authors.initials: K
authors.lastname: Jayamoorthy
mesh_terms: D000327:Adsorption; D001665:Binding Sites; D004583:Electrons; D005290:Ferric Compounds / Q000737:chemistry*; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry*; D007093:Imidazoles / Q000138:chemical synthesis / Q000737:chemistry*; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D010616:Phenanthrenes / Q000138:chemical synthesis / Q000737:chemistry*; D012666:Semiconductors; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D005290:Ferric Compounds; D005456:Fluorescent Dyes; D007093:Imidazoles; D058185:Magnetite Nanoparticles; D010616:Phenanthrenes; C000499:ferric oxide