title: Real-time monitoring of nanomolar binding to a cyclodextrin monolayer immobilized on a Si/SiO2/novolac surface using white light reflectance spectroscopy: the case of triclosan.
abstract: The monitoring of the antibacterial agent triclosan binding at nanomolar concentration from an aqueous solution by employing a well-packed monolayer with a predetermined single orientation made of specifically synthesized 2,3-dimethyl-6-(undec-10-enamide)-6-deoxy-β-cyclodextrin (DMBUA) on a silicon wafer (Si/SiO(2)) coated with a novolac resin is reported. A white light reflectance spectroscopy (WLRS) setup was used for the real-time monitoring of the DMBUA deposition and triclosan binding processes. Film thicknesses obtained by WLRS were in very good agreement with the ones measured by X-ray reflectivity (XRR) experiments. Triclosan binds strongly to the DMBUA monolayer (logK(assoc)=6.68). NMR studies in aqueous solution indicated that the chlorophenolyl ring rather than the dichlorophenyl ring is preferentially inserted into DMBUA cups. The current detecting system that requires no tedious surface chemistry, no thiolated cyclodextrins, no gold surfaces, and no expensive equipment may be useful in capturing small molecules and may permit various applications, e.g., preparation of antimicrobial surfaces.
authors.affiliation: Institute of Physical Chemistry, NCSR Demokritos, Ag. Paraskevi 15310, Athens, Greece.
authors.forename: Davide
authors.initials: D
authors.lastname: Maffeo
authors.forename: Zhivko
authors.initials: Z
authors.lastname: Velkov
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Misiakos
authors.forename: Konstantina
authors.initials: K
authors.lastname: Mergia
authors.forename: Anastasia
authors.initials: A
authors.lastname: Paulidou
authors.forename: Maria
authors.initials: M
authors.lastname: Zavali
authors.forename: Irene M
authors.initials: IM
authors.lastname: Mavridis
authors.forename: Konstantina
authors.initials: K
authors.lastname: Yannakopoulou
mesh_terms: D000891:Anti-Infective Agents, Local / Q000737:chemistry*; D001665:Binding Sites; D003505:Cyclodextrins / Q000737:chemistry*; D008027:Light; D012825:Silicon / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013057:Spectrum Analysis; D014260:Triclosan / Q000737:chemistry*
chemical_list: D000891:Anti-Infective Agents, Local; D003505:Cyclodextrins; D014260:Triclosan; D012822:Silicon Dioxide; D012825:Silicon