INVESTIGADORES
BERTOLOTTI Sonia Graciela
artículos
Título:
The use of molecular probes for the characterization of dispersions of functionalized silica nanoparticles
Autor/es:
VALERIA B. ARCE, SONIA G. BERTOLOTTI, FERNANDO J.V.E. OLIVEIRA, CLAUDIO AIROLDI, MÓNICA C. GONZALEZ, PATRICIA E. ALLEGRETTI, DANIEL O. MÁRTIRE
Revista:
SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY.
Editorial:
Elsevier
Referencias:
Año: 2009 vol. 73 p. 54 - 60
ISSN:
1386-1425
Resumen:
Butoxylated silica nanoparticles (BSN) were prepared by esterification of the silanol groups of fumed
silica nanoparticles with butanol and characterized by 13C and 29Si NMR and thermogravimetry. The
molecular probes benzophenone (BP) and safranine-T were used to investigate the BSN suspensions in
water:acetonitrile.
Laser flash-photolysis experiments at exc = 266nm performed with BSN suspended in acetonitrile:
aqueous phosphate buffer supported previous results of our group obtained by time-resolved
phosphorescence experiments and showed that only free and adsorbed excited triplet states of BP and
diphenylketyl radicals contribute to the signals.
The UVvis spectroscopic and photophysical properties of safranine-T are strongly solvent-dependent.
Thus, the analysis of the emission spectra and fluorescence lifetimes yielded information on the localization
of this probe molecule in suspensions of BSN and of the bare silica nanoparticles. The values of
the equilibrium constant for the adsorption of the ground-state safranine-T on the particles were found
to be (9.2±0.8)×104, (7.2±0.8)×105, and (3.0±0.1)×104 for the BSN in 1:1 acetonitrile:water, SiO2 in
1:1 acetonitrile:water, and SiO2 in acetonitrile, respectively.
1:1 acetonitrile:water, and SiO2 in acetonitrile, respectively.
aqueous phosphate buffer supported previous results of our group obtained by time-resolved
phosphorescence experiments and showed that only free and adsorbed excited triplet states of BP and
diphenylketyl radicals contribute to the signals.
The UVvis spectroscopic and photophysical properties of safranine-T are strongly solvent-dependent.
Thus, the analysis of the emission spectra and fluorescence lifetimes yielded information on the localization
of this probe molecule in suspensions of BSN and of the bare silica nanoparticles. The values of
the equilibrium constant for the adsorption of the ground-state safranine-T on the particles were found
to be (9.2±0.8)×104, (7.2±0.8)×105, and (3.0±0.1)×104 for the BSN in 1:1 acetonitrile:water, SiO2 in
1:1 acetonitrile:water, and SiO2 in acetonitrile, respectively.
1:1 acetonitrile:water, and SiO2 in acetonitrile, respectively.
molecular probes benzophenone (BP) and safranine-T were used to investigate the BSN suspensions in
water:acetonitrile.
Laser flash-photolysis experiments at exc = 266nm performed with BSN suspended in acetonitrile:
aqueous phosphate buffer supported previous results of our group obtained by time-resolved
phosphorescence experiments and showed that only free and adsorbed excited triplet states of BP and
diphenylketyl radicals contribute to the signals.
The UVvis spectroscopic and photophysical properties of safranine-T are strongly solvent-dependent.
Thus, the analysis of the emission spectra and fluorescence lifetimes yielded information on the localization
of this probe molecule in suspensions of BSN and of the bare silica nanoparticles. The values of
the equilibrium constant for the adsorption of the ground-state safranine-T on the particles were found
to be (9.2±0.8)×104, (7.2±0.8)×105, and (3.0±0.1)×104 for the BSN in 1:1 acetonitrile:water, SiO2 in
1:1 acetonitrile:water, and SiO2 in acetonitrile, respectively.
1:1 acetonitrile:water, and SiO2 in acetonitrile, respectively.
aqueous phosphate buffer supported previous results of our group obtained by time-resolved
phosphorescence experiments and showed that only free and adsorbed excited triplet states of BP and
diphenylketyl radicals contribute to the signals.
The UVvis spectroscopic and photophysical properties of safranine-T are strongly solvent-dependent.
Thus, the analysis of the emission spectra and fluorescence lifetimes yielded information on the localization
of this probe molecule in suspensions of BSN and of the bare silica nanoparticles. The values of
the equilibrium constant for the adsorption of the ground-state safranine-T on the particles were found
to be (9.2±0.8)×104, (7.2±0.8)×105, and (3.0±0.1)×104 for the BSN in 1:1 acetonitrile:water, SiO2 in
1:1 acetonitrile:water, and SiO2 in acetonitrile, respectively.
1:1 acetonitrile:water, and SiO2 in acetonitrile, respectively.
13C and 29Si NMR and thermogravimetry. The
molecular probes benzophenone (BP) and safranine-T were used to investigate the BSN suspensions in
water:acetonitrile.
Laser flash-photolysis experiments at exc = 266nm performed with BSN suspended in acetonitrile:
aqueous phosphate buffer supported previous results of our group obtained by time-resolved
phosphorescence experiments and showed that only free and adsorbed excited triplet states of BP and
diphenylketyl radicals contribute to the signals.
The UVvis spectroscopic and photophysical properties of safranine-T are strongly solvent-dependent.
Thus, the analysis of the emission spectra and fluorescence lifetimes yielded information on the localization
of this probe molecule in suspensions of BSN and of the bare silica nanoparticles. The values of
the equilibrium constant for the adsorption of the ground-state safranine-T on the particles were found
to be (9.2±0.8)×104, (7.2±0.8)×105, and (3.0±0.1)×104 for the BSN in 1:1 acetonitrile:water, SiO2 in
1:1 acetonitrile:water, and SiO2 in acetonitrile, respectively.
1:1 acetonitrile:water, and SiO2 in acetonitrile, respectively.
aqueous phosphate buffer supported previous results of our group obtained by time-resolved
phosphorescence experiments and showed that only free and adsorbed excited triplet states of BP and
diphenylketyl radicals contribute to the signals.
The UVvis spectroscopic and photophysical properties of safranine-T are strongly solvent-dependent.
Thus, the analysis of the emission spectra and fluorescence lifetimes yielded information on the localization
of this probe molecule in suspensions of BSN and of the bare silica nanoparticles. The values of
the equilibrium constant for the adsorption of the ground-state safranine-T on the particles were found
to be (9.2±0.8)×104, (7.2±0.8)×105, and (3.0±0.1)×104 for the BSN in 1:1 acetonitrile:water, SiO2 in
1:1 acetonitrile:water, and SiO2 in acetonitrile, respectively.
1:1 acetonitrile:water, and SiO2 in acetonitrile, respectively.
exc = 266nm performed with BSN suspended in acetonitrile:
aqueous phosphate buffer supported previous results of our group obtained by time-resolved
phosphorescence experiments and showed that only free and adsorbed excited triplet states of BP and
diphenylketyl radicals contribute to the signals.
The UVvis spectroscopic and photophysical properties of safranine-T are strongly solvent-dependent.
Thus, the analysis of the emission spectra and fluorescence lifetimes yielded information on the localization
of this probe molecule in suspensions of BSN and of the bare silica nanoparticles. The values of
the equilibrium constant for the adsorption of the ground-state safranine-T on the particles were found
to be (9.2±0.8)×104, (7.2±0.8)×105, and (3.0±0.1)×104 for the BSN in 1:1 acetonitrile:water, SiO2 in
1:1 acetonitrile:water, and SiO2 in acetonitrile, respectively.
1:1 acetonitrile:water, and SiO2 in acetonitrile, respectively.
±0.8)×104, (7.2±0.8)×105, and (3.0±0.1)×104 for the BSN in 1:1 acetonitrile:water, SiO2 in
1:1 acetonitrile:water, and SiO2 in acetonitrile, respectively.2 in acetonitrile, respectively.