Potentiometric titrations, fluorescence versus pH titrations, dynamic light scattering and fluorescence polarization anisotropy studies demonstrate that inside the nanodimensioned Triton X-100 micelles, 1-pyrenecarboxylic acid, PCOO<sup>-</sup>, forms an apical complex with the Zn<sup>2+</sup> cation encircled by a lipophilic cyclen ligand and hugely increasing its fluorescence. The ability of the Zn<sup>2+</sup>-cyclen-PCOO<sup>-</sup> complex plus its micellar container to act as a fluorescent sensor to evaluate the lipophilicity of molecular species is demonstrated on the fatty acid series CH <sub>3</sub>(CH<sub>2</sub>)<sub>x</sub>COOH (x=0-16). At pH 7.4 a decrease in fluorescence is observed on the addition of fatty acids that is directly related to their chain length, that is, to their tendency to enter the micellar containers, where they dislocate PCOO<sup>-</sup> from the Zn<sup>2+</sup> centre. The independent determination of fatty acid pK<sub>a</sub> values in the presence of Triton X-100 micelles confirms that our fluorescent micellar device is capable of sensing their lipophilicity. © 2008 Wiley-VCH Verlag GmbH &amp; Co. KGaA.

Pallavicini, P., Chirico, G., Collini, M., D'Alfonso, L., Denat, F., Diaz Fernandez, Y., et al. (2008). Micelles as Containers for Self-Assembled Nanodevices: A Fluorescent Sensor for Lipophilicity. CHEMPHYSCHEM, 9(12), 1729-1737 [10.1002/cphc.200800292].

Micelles as Containers for Self-Assembled Nanodevices: A Fluorescent Sensor for Lipophilicity

CHIRICO, GIUSEPPE;COLLINI, MADDALENA;D'ALFONSO, LAURA;
2008

Abstract

Potentiometric titrations, fluorescence versus pH titrations, dynamic light scattering and fluorescence polarization anisotropy studies demonstrate that inside the nanodimensioned Triton X-100 micelles, 1-pyrenecarboxylic acid, PCOO-, forms an apical complex with the Zn2+ cation encircled by a lipophilic cyclen ligand and hugely increasing its fluorescence. The ability of the Zn2+-cyclen-PCOO- complex plus its micellar container to act as a fluorescent sensor to evaluate the lipophilicity of molecular species is demonstrated on the fatty acid series CH 3(CH2)xCOOH (x=0-16). At pH 7.4 a decrease in fluorescence is observed on the addition of fatty acids that is directly related to their chain length, that is, to their tendency to enter the micellar containers, where they dislocate PCOO- from the Zn2+ centre. The independent determination of fatty acid pKa values in the presence of Triton X-100 micelles confirms that our fluorescent micellar device is capable of sensing their lipophilicity. © 2008 Wiley-VCH Verlag GmbH & Co. KGaA.
Articolo in rivista - Articolo scientifico
Scientifica
micelles, light scattering, pH, fluorescence
English
1729
1737
Pallavicini, P., Chirico, G., Collini, M., D'Alfonso, L., Denat, F., Diaz Fernandez, Y., et al. (2008). Micelles as Containers for Self-Assembled Nanodevices: A Fluorescent Sensor for Lipophilicity. CHEMPHYSCHEM, 9(12), 1729-1737 [10.1002/cphc.200800292].
Pallavicini, P; Chirico, G; Collini, M; D'Alfonso, L; Denat, F; Diaz Fernandez, Y; Pasotti, L; Rousselin, Y; Sok, N
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/10281/3327
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