1. Photoswitchable NIR-Emitting Gold Nanoparticles
- Author
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Giulia Battistelli, Marco Montalti, Federico Ramadori, Jeannette Manzi, Gloria Guidetti, Alessandro Gambarin, Andrea Cantelli, Luca Gabrielli, Fabrizio Mancin, Sara Bonacchi, Matteo Calvaresi, DIP. DI CHIMICA 'G.CIAMICIAN', DIPARTIMENTO DI CHIMICA 'GIACOMO CIAMICIAN', Da definire, AREA MIN. 03 - Scienze chimiche, Bonacchi, Sara, Cantelli, Andrea, Battistelli, Giulia, Guidetti, Gloria, Calvaresi, Matteo, Manzi, Jeannette, Gabrielli, Luca, Ramadori, Federico, Gambarin, Alessandro, Mancin, Fabrizio, and Montalti, Marco
- Subjects
Materials science ,Energy transfer ,gold ,luminescence ,nanoparticles ,near infrared ,stimuli-responsive compounds ,Catalysis ,Chemistry (all) ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Catalysi ,Nanomaterials ,Absorbance ,chemistry.chemical_compound ,stimuli-responsive compound ,nanoparticle ,General Chemistry ,General Medicine ,Chromophore ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Azobenzene ,chemistry ,Colloidal gold ,Luminescence ,0210 nano-technology ,Excitation - Abstract
open 11 no Nome progetto: Graphene Flagship Photo-switching of the NIR emission of gold nanoparticles (GNP) upon photo-isomerization of azobenzene ligands, bound to the surface, is demonstrated. Photophysical results confirm the occurrence of an excitation energy transfer process from the ligands to the GNP that produces sensitized NIR emission. Because of this process, the excitation efficiency of the gold core, upon excitation of the ligands, is much higher for the trans form than for the cis one, and tâc photo-isomerization causes a relevant decrease of the GNP NIR emission. As a consequence, photo-isomerization can be monitored by ratiometric detection of the NIR emission upon dual excitation. The photo-isomerization process was followed in real-time through the simultaneous detection of absorbance and luminescence changes using a dedicated setup. Surprisingly, the photo-isomerization rate of the ligands, bound to the GNP surface, was the same as measured for the chromophores in solution. This outcome demonstrated that excitation energy transfer to gold assists photo-isomerization, rather than competing with it. These results pave the road to the development of new, NIR-emitting, stimuli-responsive nanomaterials for theranostics. partially_open embargoed_20170812 Bonacchi, Sara; Cantelli, Andrea; Battistelli, Giulia; Guidetti, Gloria; Calvaresi, Matteo; Manzi, Jeannette; Gabrielli, Luca; Ramadori, Federico; Gambarin, Alessandro; Mancin, Fabrizio; Montalti, Marco Bonacchi, Sara; Cantelli, Andrea; Battistelli, Giulia; Guidetti, Gloria; Calvaresi, Matteo; Manzi, Jeannette; Gabrielli, Luca; Ramadori, Federico; Gambarin, Alessandro; Mancin, Fabrizio; Montalti, Marco
- Published
- 2016