A comprehensive investigation of amino grafted mesoporous silica nanoparticles supramolecular assemblies to host photoactive chlorophyll a in aqueous solution
Articolo
Data di Pubblicazione:
2019
Citazione:
A comprehensive investigation of amino grafted mesoporous silica nanoparticles supramolecular assemblies to host photoactive chlorophyll a in aqueous solution / V. Rizzi, J. Gubitosa, P. Fini, F. Fanelli, A. Fraix, S. Sortino, A. Agostiano, L. De Cola, A. Nacci, P. Cosma. - In: JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. A, CHEMISTRY. - ISSN 1010-6030. - 377(2019), pp. 149-158. [10.1016/j.jphotochem.2019.03.041]
Abstract:
Highly ordered Mesoporous Silica Nanoparticles (MSNs), belonging to MCM-41 family (100 nm wide), with a mean pore size of about 4 nm, are used as carrier for the hydrophobic photosensitizer (PS) Chlorophyll a (Chl) in water medium. In future perspective to study the proposed system in Photodynamic Therapy (PDT) and/or in antimicrobial-PDT (aPDT), advances in Chl studies in aqueous solution, mimicking the biological environment, were presented during this work with the main aim to obtain a supramolecular assembly able to host photoactive Chl in water medium. As synthetized MSNs and amino grafted MSNs (MSNs-NH 2 ) were studied and carefully characterized, with and without Chl, using TGA, SEM, TEM, SAXS, Nitrogen physisorption isotherms, Z-potential investigation, FTIR-ATR and UV–vis absorption/fluorescence analyses, including also the Chl fluorescence lifetime evaluation. To drive Chl inside the pores, the drug loading method by using the adsorption process, was adopted. The NH 2 moieties exerted a key role to host Chl inside the MSNs-NH 2 pores, allowing to obtain Chl as monomer. Electrostatic interactions through positively charged amino groups were evidenced, along with the hydrogen bond presence involving the pigment hydrated form and the MSNs-NH 2 . Two Chl populations, i.e. ascribed to the monomeric and dimeric one, were revealed by 1 Chl* lifetime measurements and steady state fluorescence emission. The presence of photoactive Chl molecules was demonstrated with the qualitative evaluation of 1 O 2 by means of chemical probes.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Chlorophyll a; Mesoporous silica nanoparticles; Photochemistry; ROS; Singlet oxygen
Elenco autori:
V. Rizzi, J. Gubitosa, P. Fini, F. Fanelli, A. Fraix, S. Sortino, A. Agostiano, L. De Cola, A. Nacci, P. Cosma
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