title: Synthesis of β-cyclodextrin diazonium salts and electrochemical immobilization onto glassy carbon and gold surfaces.
abstract: This study shows that diazotized β-cyclodextrin (β-CD) can be produced, isolated, and immobilized onto glassy carbon and gold surfaces. 4-(1,2,3-Triazol-4-yl)benzenediazonium-β-CD tetrafluoroborate (pDz-β-CD) and 3-(1,2,3-triazol-4-yl)benzenediazonium-β-CD tetrafluoroborate (mDz-β-CD) were successfully prepared by Cu((I))-catalyzed azide alkyne coupling (CuAAC) of 6-monodeoxy-6-monoazido-β-cyclodextrin (N(3)-β-CD) and 4-ethynylaniline and 3-ethynylaniline, respectively, followed by diazotization. The products were isolated and stored successfully for several months at -18 °C. The intermediates and products were verified by Attenuated Total Reflectance Fourier Transform Infrared, Nuclear Magnetic Resonance, and Heteronuclear Single Quantum Coherence. pDz-β-CD and mDz-β-CD were immobilized onto glassy carbon and gold surfaces facilitated by electrochemical reduction of the diazonium group. The thus generated aryl radical reacted with the surface. The modified gold surfaces were investigated by Polarization Modulation Infrared Reflection Absorption Spectroscopy and cyclic voltammetry employing the redox probe K(3)Fe(CN)(6) to analyze the extent of blocking of the surfaces. Finally, the availability of the cavity of surface-immobilized β-CD was shown by complexation of ferrocene followed by cyclic voltametric analysis.
authors.affiliation: Section of Chemistry, Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 57, DK-9000 Aalborg, Denmark.
authors.forename: Jakob Stensgaard
authors.initials: JS
authors.lastname: Diget
authors.forename: Helga Nørgaard
authors.initials: HN
authors.lastname: Petersen
authors.forename: Henrik
authors.initials: H
authors.lastname: Schaarup-Jensen
authors.forename: Anders Ulrik
authors.initials: AU
authors.lastname: Sørensen
authors.forename: Thorbjørn Terndrup
authors.initials: TT
authors.lastname: Nielsen
authors.forename: Steen Uttrup
authors.initials: SU
authors.lastname: Pedersen
authors.forename: Kim
authors.initials: K
authors.lastname: Daasbjerg
authors.forename: Kim Lambertsen
authors.initials: KL
authors.lastname: Larsen
authors.forename: Mogens
authors.initials: M
authors.lastname: Hinge