title: Binding of a cyclic organoselenium compound with gold nanoparticles (GNP) and its effect on electron transfer properties.
abstract: Binding of a cyclic organoselenium compound, DL-trans-3,4-dihydroxy-1-selenolane (DHSred) with gold nanoparticles (GNP) of different sizes was studied by absorption spectroscopy, dynamic light scattering (DLS), transmission electron microscope (TEM), surface enhanced Raman spectroscopy (SERS) and zeta-potential (ζ) measurements. GNP of different size were synthesized by varying the reaction conditions and their size was determined by DLS and TEM techniques. The absorption spectral data showed red shift in the surface plasmon resonance (SPR) band indicating increase in the size of GNP on binding to DHSred. SERS studies confirmed that the binding of DHSred with GNP is through selenium center with planar orientation of DHSred on the GNP surface. The product of the number of binding sites (n) in GNP and the binding constant (K) was estimated for GNP of different particle size. The zeta potential (ζ) value of GNP decreased marginally in the presence of DHSred. Further, the binding of DHSred with GNP was found to enhance its reactivity with 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radicals (ABTS(·-)) and the reactivity increased with decrease in the GNP size. Such enhancement in the reducing ability may have a greater impact on the antioxidant activity of DHSred.
authors.affiliation: Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India.
authors.forename: Pavitra V
authors.initials: PV
authors.lastname: Kumar
authors.affiliation: Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India. Electronic address: beenam@barc.gov.in.
authors.forename: Beena G
authors.initials: BG
authors.lastname: Singh
authors.affiliation: Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India.
authors.forename: Nandita
authors.initials: N
authors.lastname: Maiti
authors.affiliation: Department of Chemistry, School of Science, Tokai University, Hiratsuka-shi, Kanagawa 259-1292, Japan.
authors.forename: Michio
authors.initials: M
authors.lastname: Iwaoka
authors.affiliation: Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India. Electronic address: kindira@barc.gov.in.
authors.forename: K Indira
authors.initials: KI
authors.lastname: Priyadarsini
mesh_terms: D004579:Electron Transport; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D016566:Organoselenium Compounds / Q000737:chemistry*; D013059:Spectrum Analysis, Raman; D020349:Surface Plasmon Resonance
chemical_list: D016566:Organoselenium Compounds; D006046:Gold
keywords: Antioxidant; Electron transfer; Gold nanoparticles; SERS; Selenolane