Two-Photon Photolysis of 2-Nitrobenzaldehyde Monitored by Fluorescent-Labeled Nanocapsules

Diaspro, Alberto; Federici, Federico; Viappiani, Cristiano; Krol, Silke; Pisciotta, Marzia; Chirico, Giuseppe; Cannone, Fabio; Gliozzi, Alessandra

doi:10.1021/jp034921i

Cited by 20 publications

(16 citation statements)

References 25 publications

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“…Reported for the first time, is the experimental evidence of 2PE photolysis of a caged proton compound, 2-nitrobenzaldehyde (o-NBA), monitored using a new sensor system that utilizes fluorescent-labelled nanocapsules, i.e. a fluorescent nanostructured shell of micrometric size and nanometric thickness (Diaspro et al 2003). The photo-labile 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 photoactivable-caged compounds.…”

Section: Fcs Applicationsmentioning

confidence: 99%

Two-photon fluorescence excitation and related techniques in biological microscopy

Diaspro

Chirico

Collini

2005

Quart. Rev. Biophys.

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281

217

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This review is concerned with two-photon excited fluorescence microscopy (2PE) and related techniques, which are probably the most important advance in optical microscopy of biological specimens since the introduction of confocal imaging. The advent of 2PE on the scene allowed the design and performance of many unimaginable biological studies from the single cell to the tissue level, and even to whole animals, at a resolution ranging from the classical hundreds of nanometres to the single molecule size. Moreover, 2PE enabled long-term imaging of in vivo biological specimens, image generation from deeper tissue depth, and higher signal-to-noise images compared to wide-field and confocal schemes. However, due to the fact that up to this time 2PE can only be considered to be in its infancy, the advantages over other techniques are still being evaluated. Here, after a brief historical introduction, we focus on the basic principles of 2PE including fluorescence correlation spectroscopy. The major advantages and drawbacks of 2PE-based experimental approaches are discussed and compared to the conventional single-photon excitation cases. In particular we deal with the fluorescence brightness of most used dyes and proteins under 2PE conditions, on the optical consequences of 2PE, and the saturation effects in 2PE that mostly limit the fluorescence output. A complete section is devoted to the discussion of 2PE of fluorescent probes. We then offer a description of the central experimental issues, namely: choice of microscope objectives, two-photon excitable dyes and fluorescent proteins, choice of laser sources, and effect of the optics on 2PE sensitivity. An inevitably partial, but vast, overview of the applications and a large and up-to-date bibliography terminate the review. As a conclusive comment, we believe that 2PE and related techniques can be considered as a mainstay of the modern biophysical research milieu and a bright perspective in optical microscopy.

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Section: Fcs Applicationsmentioning

confidence: 99%

Two-photon fluorescence excitation and related techniques in biological microscopy

Diaspro

Chirico

Collini

2005

Quart. Rev. Biophys.

Self Cite

281

217

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“…The stokes shift was 147 nm, which may be due to intra-molecular resonance effect [15,16]. The fluorescence quantum yield is 0.386, which indicated in a certain extent that the introduction of symmetric D-π-A-π-D structure lead to more homogeneous distribution density of electron cloud in the molecular conjugated system [17]. The two photon fluorescence spectra of the fluorenone derivative W-J-B in DMF solution at different pumped power (excited by 750 nm wavelength) were researched.…”

Section: Resultsmentioning

confidence: 90%

Preparation, Linear Spectrum and Nonlinear Two-photon Absorption Properties of Fluorenone Derivative Containing 4-Methoxystyrene

Chi¹,

Li²,

Wu³

2014

Proceedings of the 2015 International Conference on Material Science and Applications

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Abstract.The nonlinear optics is a new and important branch in the field of optical physics. Compared with the traditional optics, the nonlinear optics can produce many special phenomena such as frequency doubling, optical limiting, two-photon absorption and so on. Therefore, it has great potential for application in high technology. In this research, A novel fluorenone derivative containing 4-methoxystyrene with symmetric structure D-π-A-π-D is prepared using the heck reaction, namely, 2,7-bis((E)-4-methoxystyryl)-9H-fluoren-9-one(W-J-B). The linear spectrum including ultraviolet absorption spectra and one-photon fluorescence emission spectra are measured, the nonlinear two-photon fluorescence emission spectra is researched in different excitation wavelength and powers. The results exhibit that this novel organic material has good two-photon absorption performance and nonlinear optical effect, which has potential application prospect in the field of new and high technology such as frequency up-conversion, 3D micro-fabrication, photodynamic therapy, 3D optical data storage and so on.

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“…This UV exposure will allow regeneration of chitosan from its imino derivative while assisting in the sterilization of the scaffold system. The mechanism of 2‐nitrobenzaldehyde photolysis has been well established and been explored for other photoactivatable‐caged compounds used in imaging applications . The tentative photolysis mechanism of iminochitosan is presented in the Fig.…”

Section: Resultsmentioning

confidence: 99%

“…The mechanism of 2-nitrobenzaldehyde photolysis has been well established and been explored for other photoactivatable-caged compounds used in imaging applications. [44][45][46] The tentative photolysis mechanism of iminochitosan is presented in the Fig. 2.…”

Section: Nitrobenzyl-chitosan Synthesis and Its Photolysismentioning

confidence: 99%

A smart methodology to fabricate electrospun chitosan nanofiber matrices for regenerative engineering applications

Nada

James

Shelke

et al. 2014

Polymers for Advanced Techs

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The electrospinning of chitosan remains challenging due to its rigid crystalline structure, insufficient viscosity, and limited solubility in common organic solvents. This work presents a “smart” chitosan modification that allows electrospinning irrespective of molecular weight or deacetylation value and without blending with synthetic polymers. A novel derivative, namely 2‐nitrobenzyl‐chitosan (NB), at various molar compositions of chitosan:2‐nitrobenzaldehyde (1:1 (NB‐1), 1:0.5 (NB‐2), 1:0.25 (NB‐3)) was synthesized by the reaction between amino groups of chitosan and aldehyde groups of 2‐nitrobenzaldehyde. In this Schiff base, 2‐nitrobenzaldehyde protects the amine functionalities of chitosan and improves its solubility in trifluoroacetic acid. 2‐nitrobenzaldehyde is a photoactivatable‐caged compound that cleaves off from iminochitosan on ultraviolet exposure yielding neat chitosan. Derivatives showed improved solubility in trifluoroacetic acid and dynamic viscosities in the range of 1.34 ± 0.7 to 12 ± 0.5 Pa·s based on the degree of substitution and concentration. Electrospinning conditions were optimized to produce bead free nanofibers in the range of 100–600 nm, and concentrations beyond 12% (wt/v) for NB‐1 and NB‐2, and 15% (wt/v) for NB‐3 were suitable. Photolysis did not alter fiber morphology; however, regenerated chitosan matrices were soluble in culture media presumably due to the presence of 2‐nitrosobenzoic acid in trace amounts. Human skin fibroblasts exhibited excellent (>90%) cytocompatibility on treatment with polymer extractions from cross‐linked regenerated chitosan matrices prepared to the ISO standard. Newly synthesized iminochitosan derivatives were very effective against microorganisms including bacteria (Gram‐positive and Gram‐negative), fungi, and yeast. These fiber matrices may serve as scaffolds for a variety of tissue healing and factor delivery applications. Copyright © 2014 John Wiley & Sons, Ltd.

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Two-Photon Photolysis of 2-Nitrobenzaldehyde Monitored by Fluorescent-Labeled Nanocapsules

Cited by 20 publications

References 25 publications

Two-photon fluorescence excitation and related techniques in biological microscopy

Two-photon fluorescence excitation and related techniques in biological microscopy

Preparation, Linear Spectrum and Nonlinear Two-photon Absorption Properties of Fluorenone Derivative Containing 4-Methoxystyrene

A smart methodology to fabricate electrospun chitosan nanofiber matrices for regenerative engineering applications

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