The up-conversion process based on triplet-triplet annihilation (TTA-UC) is one of the most promising strategies to combine the low energy of two photons to generate one photon with higher energy, giving rise to an Anti-Stoke emission.1 TTA-UC has been attracting great attention for the potential application in many fields (for example in solar energy optimized harvesting, or for high resolution bioimaging and phototherapy);2,-4 but an important step forward in the application of TTA-UC systems in real devices is the incorporation of the dyes (a couple of units acting as energy antenna or donor and acceptor) into solid supports.5 To achieve this goal a benchmark couple of chromophores, Platinum Octa-ethyl Porphyrin (PtOEP) as donor and 9,10-Diphenylanthracene (DPA) as acceptor, has been incorporated in oleic acid/silica core/shell nanocapsules, through a self- assembly microemulsion mechanism.6,7 The upconversion emission has been detected in solid state and water dispersion under a very low power excitation (27 µW/cm2 ) and without previous deoxygenation. In fact, the external silica shell acts as potential oxygen barrier, helped by the unsaturated fatty acids are able to efficiently quench the singlet oxygen. The nanostructured uc-system thus developed, has been used to study the optical communication in a periodic and excitable regime; where the receiver is represented by the incapsulated PtOEP/DPA couple, working in phasic-excitable regime and the transmitter consists of the Belousov- Zhabotinsky (BZ) oscillatory reaction. The signal of the receiver is detected at different wavelength and moreover, changing the excitation wavelength, the intensity could be continuous or modulated in time, mimicking the oscillatory dynamics of neurons.8 The experiments demonstrate that the rigid silica shell of the nanocapsules is efficient in protecting the luminescent compounds from the harsh environment of the BZ reaction, producing a stable signal. Further experiments of optical communication are in progress. Bibliography 1. Gray V., Photochemistry, 2019, 404-420. 2. Kinoshita M., Sasaki Y., Amemori S., Harada N., Hu Z., Liu Z., Ono L.K., Qi Y., Yanai N., Kimizuka N., ChemPhotoChem, 2020, 4, 1-9. 3. Liu Q., Yang T., Feng W., Li F., J. Am. Chem. Soc., 2012, 134, 5390-5397. 4. Massaro G., Hernando J., Ruiz-Molina D., Roscini C., Latterini L., Chem. Mater., 2016, 28, 738- 745. 5. Latterini L., Massaro G., Penconi M., Gentili P.L., Roscini C., Ortica F., Dalton Trans., 2018, 47, 8557-8565. 6. Kwon O.S., Kim J.Hy., Cho J.K., Kim J.Ho., ACS Appl. Mater. Interfaces, 2015, 7, 318-325. 7. Massaro G., Gentili P.L., Ambrogi V., Nocchetti M., Marmottini F., Ortica F., Latterini L., Micropor. Mesopor. Mat., 2017, 246, 120-129. 8. Gentili P.L., Giubila M.S., Germani R., Romani A., Nicoziani A., Spalletti A., Heron B.M., Angew. Chem., 2017, 129, 7643-7648.
“Design of TTA-UC nanocapsules for the study of optical communication between oscillatory reaction and photo-excitable systems.”
Giulia Quaglia;Pier Luigi Gentili;Loredana Latterini
2020
Abstract
The up-conversion process based on triplet-triplet annihilation (TTA-UC) is one of the most promising strategies to combine the low energy of two photons to generate one photon with higher energy, giving rise to an Anti-Stoke emission.1 TTA-UC has been attracting great attention for the potential application in many fields (for example in solar energy optimized harvesting, or for high resolution bioimaging and phototherapy);2,-4 but an important step forward in the application of TTA-UC systems in real devices is the incorporation of the dyes (a couple of units acting as energy antenna or donor and acceptor) into solid supports.5 To achieve this goal a benchmark couple of chromophores, Platinum Octa-ethyl Porphyrin (PtOEP) as donor and 9,10-Diphenylanthracene (DPA) as acceptor, has been incorporated in oleic acid/silica core/shell nanocapsules, through a self- assembly microemulsion mechanism.6,7 The upconversion emission has been detected in solid state and water dispersion under a very low power excitation (27 µW/cm2 ) and without previous deoxygenation. In fact, the external silica shell acts as potential oxygen barrier, helped by the unsaturated fatty acids are able to efficiently quench the singlet oxygen. The nanostructured uc-system thus developed, has been used to study the optical communication in a periodic and excitable regime; where the receiver is represented by the incapsulated PtOEP/DPA couple, working in phasic-excitable regime and the transmitter consists of the Belousov- Zhabotinsky (BZ) oscillatory reaction. The signal of the receiver is detected at different wavelength and moreover, changing the excitation wavelength, the intensity could be continuous or modulated in time, mimicking the oscillatory dynamics of neurons.8 The experiments demonstrate that the rigid silica shell of the nanocapsules is efficient in protecting the luminescent compounds from the harsh environment of the BZ reaction, producing a stable signal. Further experiments of optical communication are in progress. Bibliography 1. Gray V., Photochemistry, 2019, 404-420. 2. Kinoshita M., Sasaki Y., Amemori S., Harada N., Hu Z., Liu Z., Ono L.K., Qi Y., Yanai N., Kimizuka N., ChemPhotoChem, 2020, 4, 1-9. 3. Liu Q., Yang T., Feng W., Li F., J. Am. Chem. Soc., 2012, 134, 5390-5397. 4. Massaro G., Hernando J., Ruiz-Molina D., Roscini C., Latterini L., Chem. Mater., 2016, 28, 738- 745. 5. Latterini L., Massaro G., Penconi M., Gentili P.L., Roscini C., Ortica F., Dalton Trans., 2018, 47, 8557-8565. 6. Kwon O.S., Kim J.Hy., Cho J.K., Kim J.Ho., ACS Appl. Mater. Interfaces, 2015, 7, 318-325. 7. Massaro G., Gentili P.L., Ambrogi V., Nocchetti M., Marmottini F., Ortica F., Latterini L., Micropor. Mesopor. Mat., 2017, 246, 120-129. 8. Gentili P.L., Giubila M.S., Germani R., Romani A., Nicoziani A., Spalletti A., Heron B.M., Angew. Chem., 2017, 129, 7643-7648.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
