In this paper, we report, for the first time, experimental evidence of multiphoton photolysis of a caged proton compound, 2-nitrobenzaldehyde (o-NBA), using a new sensor system that utilizes fluorescent-labeled nanocapsules, i.e., a fluorescent nanostructured shell of micrometric size and nanometric thickness. The photolabile compound undergoes one-photon absorption in the UV range (200-380 nm), and the mechanism that leads to proton release is based on the well-known 2-nitrobenzyl photochemistry, which has been used for many photoactivatable-caged compounds. Because the use of UV excitation can cause biological damage, we changed our focus to multiphoton absorption-uncaging processes. The induced pH decrease was monitored by imaging changes in the pH-dependent emission of fluorescein isothiocyanate that was embedded in a nanostructured system (so-called "nanocapsules"). The nanocapsules with covalently bound dyes allow improved stability in fluorescence monitoring. Moreover, an original image processing method is introduced to quantify the uncaging. Using a femtosecond Ti:sapphire laser that was operating at 720 nm, with a pulse width of similar to200 fs at the sample, delivered through an adapted confocal laser scanning head and a 1-min exposure time with high power (45-50 mW), we obtained appreciable photolysis of 2-nitrobenzaldehyde. So far, we demonstrated that fluorescent-labeled nanocapsules are a suitable system as fluorescence sensors

Diaspro, A., Federici, F., Viappiani, C., Krol, S., Pisciotta, M., Chirico, G., et al. (2003). Two-photon photolysis of 2-nitrobenzaldehyde monitored by fluorescent-labeled nanocapsules. JOURNAL OF PHYSICAL CHEMISTRY. B, CONDENSED MATTER, MATERIALS, SURFACES, INTERFACES & BIOPHYSICAL, 107(40), 11008-11012 [10.1021/jp034921i].

Two-photon photolysis of 2-nitrobenzaldehyde monitored by fluorescent-labeled nanocapsules

Chirico, G;
2003

Abstract

In this paper, we report, for the first time, experimental evidence of multiphoton photolysis of a caged proton compound, 2-nitrobenzaldehyde (o-NBA), using a new sensor system that utilizes fluorescent-labeled nanocapsules, i.e., a fluorescent nanostructured shell of micrometric size and nanometric thickness. The photolabile compound undergoes one-photon absorption in the UV range (200-380 nm), and the mechanism that leads to proton release is based on the well-known 2-nitrobenzyl photochemistry, which has been used for many photoactivatable-caged compounds. Because the use of UV excitation can cause biological damage, we changed our focus to multiphoton absorption-uncaging processes. The induced pH decrease was monitored by imaging changes in the pH-dependent emission of fluorescein isothiocyanate that was embedded in a nanostructured system (so-called "nanocapsules"). The nanocapsules with covalently bound dyes allow improved stability in fluorescence monitoring. Moreover, an original image processing method is introduced to quantify the uncaging. Using a femtosecond Ti:sapphire laser that was operating at 720 nm, with a pulse width of similar to200 fs at the sample, delivered through an adapted confocal laser scanning head and a 1-min exposure time with high power (45-50 mW), we obtained appreciable photolysis of 2-nitrobenzaldehyde. So far, we demonstrated that fluorescent-labeled nanocapsules are a suitable system as fluorescence sensors
No
Articolo in rivista - Articolo scientifico
Scientifica
TIME-RESOLVED PHOTOACOUSTICS; INDUCED PH-JUMP; PROTON-TRANSFER; AQUEOUS-SOLUTIONS; VOLUME CHANGES; POLYMER; NITROBENZALDEHYDE; POLYELECTROLYTES; EXCITATION; MICROSCOPY
English
11008
11012
5
Diaspro, A., Federici, F., Viappiani, C., Krol, S., Pisciotta, M., Chirico, G., et al. (2003). Two-photon photolysis of 2-nitrobenzaldehyde monitored by fluorescent-labeled nanocapsules. JOURNAL OF PHYSICAL CHEMISTRY. B, CONDENSED MATTER, MATERIALS, SURFACES, INTERFACES & BIOPHYSICAL, 107(40), 11008-11012 [10.1021/jp034921i].
Diaspro, A; Federici, F; Viappiani, C; Krol, S; Pisciotta, M; Chirico, G; Cannone, F; Gliozzi, A
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/10281/17219
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