9 research outputs found
Tetrazole as a New Anchoring Group for the Functionalization of TiO<sub>2</sub> Nanoparticles: A Joint Experimental and Theoretical Study
Functional hybrid materials are an
important tool for generating original architectures featuring desirable
properties for multiple applications. The success in creating innovative
materials with valuable functionalities relies on the close interaction
between the organic and inorganic parts of the hybrid system. Herein,
we report the use of tetrazole as an anchoring group for the photosensitization
of TiO<sub>2</sub> nanoparticles by an organic chromophore and the
related performance in dye-sensitized solar cells. The interaction
mode between the tetrazole motif and TiO<sub>2</sub> was thoroughly
investigated by various techniques. The overall study reveals that
the optoelectronic and photovoltaic properties of the dye featuring
tetrazole rival those of an analogue bearing a carboxylic acid function,
even leading to significantly enhanced photovoltage in the device.
These results demonstrate the effectiveness of the tetrazole functional
group as a serious alternative anchoring group for organic photosensitizers
in hybrid materials for energy
Average values of the binding constants for the studied systems.
<p><i>Average K values calculated by using the BenesiāHildebrand equation for all the isophorone-DNA systems studied</i>.</p><p>Average values of the binding constants for the studied systems.</p
Stern-Volmer plots for the fluorescence quenching of Isoa-c by DNA.
<p>Plot of the ratio of the isophorone derivatives fluorescence intensity before and after incremental addition of DNA as a function of the quencher concentration for the determination of the Stern-Volmer quenching rate constant.</p
Effect of the isophorone derivatives on the DNA conformation.
<p>Circular dichroism (CD) spectra of DNA (30.9 Ī¼M) treated with: A) 0.0 (black line), 12.82 (red line), 38.07 (blue line), 62.81(green line) Ī¼M (curves 1ā4) of Isoa, B) 0.0 (black line), 12.82 (red line), 38.07 (blue line), 62.81(green line) Ī¼M (curves 1ā4) of Isob, C) 0.0 (black line), 12.82 (red line), 38.07 (blue line), 62.81(green line) Ī¼M (curves 1ā4) of Isoc.</p
Plot of log [(F<sub>0</sub>-F)/F] <i>vs</i>. log [DNA].
<p>Determination of the binding constant and number of binding sites for the Iso-DNA systems.</p
Binding constant determination.
<p>Plots of 1/(A-A<sub>0</sub>) <i>vs</i>. 1/Isophorone concentration for DNA and their isophorone complexes. A<sub>0</sub> is the absorbance of DNA (at 260 nm) and A is the absorbance after isophorone addition.</p
Red Emitting Neutral Fluorescent Glycoconjugates for Membrane Optical Imaging
A family of neutral fluorescent probes
was developed, mimicking
the overall structure of natural glycolipids in order to optimize
their membrane affinity. Nonreducing commercially available di- or
trisaccharidic structures were connected to a pushāpull chromophore
based on dicyanoisophorone electron-accepting group, which proved
to fluoresce in the red region with a very large Stokes shift. This
straightforward synthetic strategy brought structural variations to
a series of probes, which were studied for their optical, biophysical,
and biological properties. The insertion properties of the different
probes into membranes were evaluated on a model system using the Langmuir
monolayer balance technique. Confocal fluorescence microscopy performed
on muscle cells showed completely different localizations and loading
efficiencies depending on the structure of the probes. When compared
to the commercially available ANEPPS, a family of commonly used membrane
imaging dyes, the most efficient probes showed a similar brightness,
but a sharper pattern was observed. According to this study, compounds
bearing one chromophore, a limited size of the carbohydrate moiety,
and an overall rod-like shape gave the best results