title: Deconvolution procedure of the UV-vis spectra. A powerful tool for the estimation of the binding of a model drug to specific solubilisation loci of bio-compatible aqueous surfactant-forming micelle.
abstract: UV-vis-spectra evolution of Nile Red loaded into Tween 20 micelles with pH and [Tween 20] have been analysed in a non-conventional manner by exploiting the deconvolution method. The number of buried sub-bands has been found to depend on both pH and bio-surfactant concentration, whose positions have been associated to Nile Red confined in aqueous solution and in the three micellar solubilisation sites. For the first time, by using an extended classical two-pseudo-phases-model, the robust treatment of the spectrophotometric data allows the estimation of Nile Red binding constant to the available loci. Hosting capability towards Nile Red is exalted by the pH enhancement. Comparison between binding constant values classically evaluated and those estimated by the deconvolution protocol unveiled that overall binding values perfectly match with the mean values of the local binding sites. This result suggests that deconvolution procedure provides more precise and reliable values, which are more representative of drug confinement.
authors.affiliation: Dipartimento di Fisica e Chimica, Università degli Studi di Palermo, Viale delle Scienze - Parco d'Orleans II - Pad. 17, 90128 Palermo, Italy.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Calabrese
authors.affiliation: Dipartimento di Scienze della Terra e del Mare (DiSTeM), Università degli Studi di Palermo, Via Archirafi 36, 90123 Palermo, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Merli
authors.affiliation: Dipartimento di Fisica e Chimica, Università degli Studi di Palermo, Viale delle Scienze - Parco d'Orleans II - Pad. 17, 90128 Palermo, Italy. Electronic address: marialiria.turcoliveri@unipa.it.
authors.forename: Maria Liria
authors.initials: ML
authors.lastname: Turco Liveri
mesh_terms: D001665:Binding Sites; D008823:Micelles; D010078:Oxazines / Q000737:chemistry*; D011136:Polysorbates / Q000737:chemistry*; D012995:Solubility; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D008823:Micelles; D010078:Oxazines; D011136:Polysorbates; D013501:Surface-Active Agents; C044808:nile red
keywords: Deconvolution; Nile Red; Specific solubilisation loci; Tween 20; UV–vis spectra; cmc