Orientation relaxation of fluorescent molecules in uniaxially drawn PVC-films during annealing

2007 ◽  
pp. 134-139 ◽  
Author(s):  
R. Neuert ◽  
H. Springer ◽  
G. Hinrichsen
Keyword(s):  
Orientation Relaxation ◽  
Fluorescent Molecules

Probing the Structural Features and the Micro-heterogeneity of Various Deep Eutectic Solvents and their Water Dilutions by the Photophysical Behaviour of Two Fluorophores

2020 ◽  
Author(s):  
Matteo Tiecco ◽  
Irene Di Guida ◽  
Pier Luigi Gentili ◽  
Raimondo Germani ◽  
Carmela Bonaccorso ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Transient Absorption ◽  
Photophysical Properties ◽  
Deep Eutectic Solvents ◽  
Structural Features ◽  
Solvation Dynamics ◽  
Structured Systems ◽  
Reduced Viscosity ◽  
Bond Network ◽  
Fluorescent Molecules

<div><div><div><p>The structural features of a series of diverse Deep Eutectic Solvents (DESs) have been investigated and characterized by means of two fluorescent probes. The spectral and photophysical properties of the latter are strictly dependent on the experienced environment, so that they can provide insights into the polarity, viscosity, hydrogen-bond network, and micro-heterogeneity of the various DESs.</p><p>In fact, the investigated DESs exhibit a variety of properties with regards to their hydrophilicity, acidity, and hydrogen-bond ability, and these details were deeply probed by the two fluorescent molecules. The effect of the addition of water, which is a key strategy for tuning the properties of these structured systems, was also tested. In particular, the excited state dynamics of the probes, measured by femtosecond-resolved transient absorption, proved instrumental in understanding the changes in the structural properties of the DESs, namely reduced viscosity and enhanced heterogeneity, as the water percentage increases. Differences between the various DESs in terms of both local microheterogeneity and bulk viscosity also emerged from the peculiar multi-exponential solvation dynamics undergone by the excited states of the probes.</p></div></div></div>

Probing the Structural Features and the Micro-heterogeneity of Various Deep Eutectic Solvents and their Water Dilutions by the Photophysical Behaviour of Two Fluorophores

2020 ◽  
Author(s):  
Matteo Tiecco ◽  
Irene Di Guida ◽  
Pier Luigi Gentili ◽  
Raimondo Germani ◽  
Carmela Bonaccorso ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Transient Absorption ◽  
Photophysical Properties ◽  
Deep Eutectic Solvents ◽  
Structural Features ◽  
Solvation Dynamics ◽  
Structured Systems ◽  
Reduced Viscosity ◽  
Bond Network ◽  
Fluorescent Molecules

<div><div><div><p>The structural features of a series of diverse Deep Eutectic Solvents (DESs) have been investigated and characterized by means of two fluorescent probes. The spectral and photophysical properties of the latter are strictly dependent on the experienced environment, so that they can provide insights into the polarity, viscosity, hydrogen-bond network, and micro-heterogeneity of the various DESs.</p><p>In fact, the investigated DESs exhibit a variety of properties with regards to their hydrophilicity, acidity, and hydrogen-bond ability, and these details were deeply probed by the two fluorescent molecules. The effect of the addition of water, which is a key strategy for tuning the properties of these structured systems, was also tested. In particular, the excited state dynamics of the probes, measured by femtosecond-resolved transient absorption, proved instrumental in understanding the changes in the structural properties of the DESs, namely reduced viscosity and enhanced heterogeneity, as the water percentage increases. Differences between the various DESs in terms of both local microheterogeneity and bulk viscosity also emerged from the peculiar multi-exponential solvation dynamics undergone by the excited states of the probes.</p></div></div></div>

scholarly journals Silver Nanoparticles Functionalized by Fluorescein Isothiocyanate or Rhodamine B Isothiocyanate: Fluorescent and Plasmonic Materials

2021 ◽  
Vol 11 (6) ◽  
pp. 2472
Author(s):  
Ilaria Fratoddi ◽  
Chiara Battocchio ◽  
Giovanna Iucci ◽  
Daniele Catone ◽  
Antonella Cartoni ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Rhodamine B ◽  
Photoelectron Spectroscopy ◽  
Transient Absorption ◽  
Fluorescein Isothiocyanate ◽  
Dye Molecules ◽  
Chemical Surface ◽  
Vis Spectroscopy ◽  
Rhodamine B Isothiocyanate ◽  
Fluorescent Molecules

This paper presents the synthesis of silver nanoparticles (AgNPs) functionalized with fluorescent molecules, in particular with xanthene-based dyes, i.e., fluorescein isothiocyanate (FITC, λmax = 485 nm) and rhodamine B isothiocyanate (RITC, λmax = 555 nm). An in-depth characterization of the particle–dye systems, i.e., AgNPs–RITC and AgNPs–FITC, is presented to evaluate their chemical structure and optical properties due to the interaction between their plasmonic and absorption properties. UV–Vis spectroscopy and the dynamic light scattering (DLS) measurements confirmed the nanosize of the AgNPs–RITC and AgNPs–FITC. Synchrotron radiation X-ray photoelectron spectroscopy (SR-XPS) was used to study the chemical surface functionalization by structural characterization, confirming/examining the isothiocyanate–metal interaction. For AgNPs–RITC, in which the plasmonic and fluorescence peak are not superimposed, the transient dynamics of the dye fluorescence were also studied. Transient absorption measurements showed that by exciting the AgNPs–RITC sample at a wavelength corresponding to the AgNP plasmon resonance, it was possible to preferentially excite the RITC dye molecules attached to the surface of the NPs with respect to the free dye molecules in the solution. These results demonstrate how, by combining plasmonics and fluorescence, these AgNPs can be used as promising systems in biosensing and imaging applications.

scholarly journals Comparing the delivery to the hair bulb of two fluorescent molecules of distinct hydrophilicities by different nanoparticles and a serum formulation

2021 ◽  
pp. 120653
Author(s):  
Cristiana Costa ◽  
Bruno Fernandes ◽  
Diana Guimarães ◽  
Eugénia Nogueira ◽  
Madalena Martins ◽  
...  
Keyword(s):  
Hair Bulb ◽  
Fluorescent Molecules

scholarly journals MoS2 pixel arrays for real-time photoluminescence imaging of redox molecules

2019 ◽  
Vol 5 (11) ◽  
pp. eaat9476 ◽  
Author(s):  
M. F. Reynolds ◽  
M. H. D. Guimarães ◽  
H. Gao ◽  
K. Kang ◽  
A. J. Cortese ◽  
...  
Keyword(s):  
New Technologies ◽  
Chemical Potential ◽  
Strong Dependence ◽  
Detection Methods ◽  
Redox Active ◽  
New Strategy ◽  
Chemical And Biological Systems ◽  
Redox Molecules ◽  
Fluorescent Molecules ◽  
Molecule Concentration

Measuring the behavior of redox-active molecules in space and time is crucial for understanding chemical and biological systems and for developing new technologies. Optical schemes are noninvasive and scalable, but usually have a slow response compared to electrical detection methods. Furthermore, many fluorescent molecules for redox detection degrade in brightness over long exposure times. Here, we show that the photoluminescence of “pixel” arrays of monolayer MoS2 can image spatial and temporal changes in redox molecule concentration. Because of the strong dependence of MoS2 photoluminescence on doping, changes in the local chemical potential substantially modulate the photoluminescence of MoS2, with a sensitivity of 0.9 mV/Hz on a 5 μm × 5 μm pixel, corresponding to better than parts-per-hundred changes in redox molecule concentration down to nanomolar concentrations at 100-ms frame rates. This provides a new strategy for visualizing chemical reactions and biomolecules with a two-dimensional material screen.

scholarly journals Fluorescence background discrimination by prebleaching.

1979 ◽  
Vol 27 (1) ◽  
pp. 96-101 ◽  
Author(s):  
T Hirschfeld
Keyword(s):  
Fluorescent Dyes ◽  
Fluorescence Decay ◽  
Free Form ◽  
Alternative Procedure ◽  
Background Fluorescence ◽  
Decay Lifetime ◽  
Fluorescent Molecules ◽  
Background Contrast

A number of electrooptical techniques are described that discriminate against background fluorescence in biologic staining, whether from sample background or unbound excess stain. These techniques are based on the fluorescent decay lifetime difference between bound stain and the sample background or between the bound stain its free form. The fluorescence decay lifetimes may be measured either directly or in a combination gated photometry scheme to substantially enhance the sample background contrast. An alternative procedure uses the photochemical bleaching of fluorescent dyes under intense exposure to time discriminate with higher selectivity, sensitivity and in a more convenient fashion between diverse fluorescent molecules.

Patterning Organic Fluorescent Molecules with SAM Patterns

2011 ◽  
Vol 1335 ◽  
Author(s):  
Qiong Wu ◽  
Juanyuan Hao ◽  
Shoulei Shi ◽  
Weifeng Wang ◽  
Nan Lu
Keyword(s):  
Organic Molecules ◽  
Low Cost ◽  
Substrate Surface ◽  
Large Area ◽  
Self Assembled Monolayer ◽  
Storage Duration ◽  
Light Emitting ◽  
High Throughput Method ◽  
Self Assembled ◽  
Fluorescent Molecules

ABSTRACTWe report a low-cost and high-throughput method to fabricate large-area light emitting pattern via thermal evaporation of organic molecules on the patterned self-assembled monolayer of homogenous 3-aminopropyltrimethoxysilane. This method is based on the selective deposition of the organic light emitting molecules on the template of self-assembled monolayer (SAM), which is patterned with nanoimprinting lithography. The selectivity can be controlled by adjusting the design of the pattern, the storage duration and the substrate temperature. The deposition selectivity of the molecules may be caused by the different binding energy of the molecules with the SAM and the substrate surface.

scholarly journals Microfluidic platform enables tailored translocation and reaction cascades in nanoliter droplet networks

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Simon Bachler ◽  
Dominik Haidas ◽  
Marion Ort ◽  
Todd A. Duncombe ◽  
Petra S. Dittrich
Keyword(s):  
Synthetic Biology ◽  
Lipid Membranes ◽  
Bottom Up ◽  
Microfluidic Platform ◽  
Alpha Hemolysin ◽  
Droplet Interface Bilayer ◽  
Translocation Experiments ◽  
Fluorescent Molecules ◽  
Reaction Cascades ◽  
Minimal Cells

AbstractIn the field of bottom-up synthetic biology, lipid membranes are the scaffold to create minimal cells and mimic reactions and processes at or across the membrane. In this context, we employ here a versatile microfluidic platform that enables precise positioning of nanoliter droplets with user-specified lipid compositions and in a defined pattern. Adjacent droplets make contact and form a droplet interface bilayer to simulate cellular membranes. Translocation of molecules across membranes are tailored by the addition of alpha-hemolysin to selected droplets. Moreover, we developed a protocol to analyze the translocation of non-fluorescent molecules between droplets with mass spectrometry. Our method is capable of automated formation of one- and two-dimensional droplet networks, which we demonstrated by connecting droplets containing different compound and enzyme solutions to perform translocation experiments and a multistep enzymatic cascade reaction across the droplet network. Our platform opens doors for creating complex artificial systems for bottom-up synthetic biology.

Orientation-relaxation of polyenes produced in heated PVA film

Polymer ◽  
1989 ◽  
Vol 30 (5) ◽  
pp. 856-859 ◽  
Author(s):  
K. Maruyama ◽  
T. Fujiwara ◽  
Y. Tanizaki
Keyword(s):  
Orientation Relaxation
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