Qualitative changes in the fluorescence spectra of intact pea leaves after photoinhibition

1991 ◽  
Vol 69 (5-6) ◽  
pp. 399-403 ◽  
Author(s):  
Wiesław I. Gruszecki ◽  
Konka Veeranjaneyulu ◽  
Roger M. Leblanc
Keyword(s):  
Energy Transfer ◽  
Chlorophyll Fluorescence ◽  
Fluorescence Intensity ◽  
Fluorescence Spectra ◽  
Fluorescence Emission ◽  
Heat Emission ◽  
High Light ◽  
Fluorescence Excitation ◽  
As Effects ◽  
Qualitative Changes

In high light (1400 W m−2) treated, intact pea leaves, a decrease in the ratio of fluorescence emission at 685 to 730 nm and an increase in fluorescence intensity between 500 and 600 nm were observed. Furthermore, photoacoustically monitored heat emission increased slightly, and O2 evolution decreased significantly. These findings are interpreted as effects of a photoprotective mechanism separating the carotenoid pool from the chlorophylls. This is supported by fluorescence excitation measurements and the results of a study on the reversibility of the process.Key words: chlorophyll fluorescence, carotenoid fluorescence, photoinhibition, photosynthesis, energy transfer.

scholarly journals Isolation and spectral characterization of phycobiliproteins

1970 ◽  
Vol 116 (2) ◽  
pp. 161-169 ◽  
Author(s):  
F. W. J. Teale ◽  
R. E. Dale
Keyword(s):  
Energy Transfer ◽  
Ionic Strength ◽  
Aqueous Medium ◽  
Fluorescence Emission ◽  
Protein Subunit ◽  
Fluorescence Excitation ◽  
Different Types ◽  
Single Protein ◽  
Polarization Spectra

Several phycobiliproteins were prepared chromatographically pure and their absorption, fluorescence-emission, fluorescence-excitation and fluorescence-excitation polarization spectra determined. Changes in these spectra with ionic strength of the aqueous medium and chromoprotein concentration were interpreted in terms of interchromophore energy transfer and protein subunit equilibria. The complexity of the polarization spectra confirms the presence of different types of chromophore, designated sensitizing (‘s’) and fluorescing (‘f’), in a single protein.

scholarly journals New insights into the autofluorescence properties of cellulose/nanocellulose

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Qijun Ding ◽  
Wenjia Han ◽  
Xia Li ◽  
Yifei Jiang ◽  
Chuanshan Zhao
Keyword(s):  
Fluorescence Intensity ◽  
Fluorescence Spectra ◽  
Fluorescence Emission ◽  
Biological Imaging ◽  
Emission Peak ◽  
Tempo Oxidation ◽  
Glycosidic Bonds ◽  
Softwood Kraft Pulp ◽  
Nano Cellulose ◽  
Alkaline Conditions

AbstractThis work explored the fluorescence properties of nano/cellulose isolated from bleached softwood kraft pulp by TEMPO oxidation. Fluorescence spectra showed that all samples exhibited a typical emission peak at 574 nm due to the probabilistic formation of unsaturated bonds by glycosidic bonds independent of lignin. Increasing the excitation wavelengths (510–530 nm) caused red shift of fluorescence emission peaks (570–585 nm) with unchanged fluorescence intensity. Conversely, changing acid/alkaline conditions led to an increase of fluorescence intensity with no shifting of fluorescence emission peak. This can be attributed to an increase in the polarity of the solution environment but does not cause interaction of functional groups within the system identified by generalized two-dimensional correlation fluorescence spectroscopy. This study provides new insight in applying nano/cellulose with special luminous characteristics in biomedicine area such as multi-color biological imaging and chemical sensing.

PHOTONIC BAND GAP EFFECT ON ENERGY TRANSFER IN Tb3+, Eu3+ CO-DOPED TiO2 INVERSE OPAL FILMS

2013 ◽  
Vol 27 (14) ◽  
pp. 1350099 ◽  
Author(s):  
ZHENDONG LIU ◽  
JI ZHOU ◽  
BO LI
Keyword(s):  
Crystal Structure ◽  
Energy Transfer ◽  
Band Gap ◽  
Fluorescence Intensity ◽  
Photonic Band Gap ◽  
Fluorescence Emission ◽  
Gap Effect ◽  
Inverse Opal ◽  
Photonic Band ◽  
Co Doped

The energy transfer from Tb 3+ to Eu 3+ co-doped TiO 2( TiO 2: Tb , Eu ) inverse opal photonic crystals was investigated by photoluminescence. The results showed that the photonic band gap enhanced energy transfer from the donor Tb 3+ to the acceptor Eu 3+. When the fluorescence emission wavelength of Tb 3+ overlaps with the photonic band gap, the fluorescence intensity of Tb 3+ is suppressed, while the fluorescence intensity of Eu 3+ is enhanced. Energy transfer efficiencies were attributed to the tuning effects of energy transfer in the photoluminescence process by photonic crystal structure.

Fluorescence spectroscopy of mechanical pulps III: Effect of chlorite delignification

1995 ◽  
Vol 73 (11) ◽  
pp. 1955-1959 ◽  
Author(s):  
Jennifer A. Olmstead ◽  
Jian H. Zhu ◽  
Derek G. Gray
Keyword(s):  
Fluorescence Spectroscopy ◽  
Fluorescence Intensity ◽  
Fluorescence Spectra ◽  
Lignin Content ◽  
Emission Spectra ◽  
Thermomechanical Pulp ◽  
Fluorescence Excitation ◽  
Lignin Removal ◽  
Mechanical Pulps ◽  
Almost All

Many paper and wood samples fluoresce, but the sources of the emission are not well understood. Fluorescence excitation and emission spectra of paper sheets prepared from thermomechanical pulp (TMP) and bleached chemithermomechanical pulp (BCTMP) showed that the emission from the BCTMP was significantly higher than that from the TMP. Removing almost all of the lignin from both pulps by means of an acid chlorite treatment did not reduce the fluorescence significantly. By means of an approximate correction for changes in sheet reflectivity caused by the chlorite treatment, the fluorescence intensity was found to increase with lignin removal. Clearly, fluorescence is not simply related to lignin content. Keywords: wood pulp, lignin, cellulose, fluorescence spectra, acid chlorite delignification.

scholarly journals Regulation of bi-color fluorescence changes of AIE supramolecular self-assembly gels by the interaction with Al3+ and energy transfer

2021 ◽  
Author(s):  
Xinxian Ma ◽  
Jinlong Yue ◽  
Bo Qiao ◽  
LIli Zhou ◽  
Yang Gao ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Self Assembly ◽  
Fluorescence Emission ◽  
Fluorescent Materials

Supramolecular fluorescent materials have attracted considerable attention in recent years since they endow specific and unique properties to materials. Nevertheless, the utilization of photo-responsive characteristics to modulate their fluorescence emission...

scholarly journals Ultrafast Electron/Energy Transfer and Intersystem Crossing Mechanisms in BODIPY-Porphyrin Compounds

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 312
Author(s):  
Yusuf Tutel ◽  
Gökhan Sevinç ◽  
Betül Küçüköz ◽  
Elif Akhuseyin Yildiz ◽  
Ahmet Karatay ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Fluorescence Spectra ◽  
Visible Region ◽  
Energy Transfer Mechanism ◽  
Free Base ◽  
Pump Probe ◽  
Harvesting Efficiency ◽  
Probe Spectroscopy ◽  
Absorption Features ◽  
Transfer Mechanisms

Meso-substituted borondipyrromethene (BODIPY)-porphyrin compounds that include free base porphyrin with two different numbers of BODIPY groups (BDP-TTP and 3BDP-TTP) were designed and synthesized to analyze intramolecular energy transfer mechanisms of meso-substituted BODIPY-porphyrin dyads and the effect of the different numbers of BODIPY groups connected to free-base porphyrin on the energy transfer mechanism. Absorption spectra of BODIPY-porphyrin conjugates showed wide absorption features in the visible region, and that is highly valuable to increase light-harvesting efficiency. Fluorescence spectra of the studied compounds proved that BODIPY emission intensity decreased upon the photoexcitation of the BODIPY core, due to the energy transfer from BODIPY unit to porphyrin. In addition, ultrafast pump-probe spectroscopy measurements indicated that the energy transfer of the 3BDP-TTP compound (about 3 ps) is faster than the BDP-TTP compound (about 22 ps). Since the BODIPY core directly binds to the porphyrin unit, rapid energy transfer was seen for both compounds. Thus, the energy transfer rate increased with an increasing number of BODIPY moiety connected to free-base porphyrin.

Effect of ABA on Photosynthesis and Chlorophyll Fluorescence in Emmenopterys henri Oliv. under High Light

2021 ◽  
Vol 68 (3) ◽  
pp. 510-518
Author(s):  
Y. F. Hao ◽  
Y. Y. Feng ◽  
L. J. Cai ◽  
Qiong Wu ◽  
L. L. Song
Keyword(s):  
Chlorophyll Fluorescence ◽  
High Light

Sensitizing effect of Yb3+ on near-infrared fluorescence emission of Cr4+-doped calcium aluminate glasses

2000 ◽  
Vol 15 (2) ◽  
pp. 278-281 ◽  
Author(s):  
Yong Gyu Choi ◽  
Kyong Hon Kim ◽  
Yong Seop Han ◽  
Jong Heo
Keyword(s):  
Energy Transfer ◽  
Calcium Aluminate ◽  
Near Infrared ◽  
Fluorescence Emission ◽  
Dipole Interaction ◽  
Energy Transfer Mechanism ◽  
Efficient Energy Transfer ◽  
Efficient Energy ◽  
Sensitizing Effect ◽  
Decay Behavior

We have demonstrated that an efficient energy transfer takes place from Yb3+ to Cr4+ in calcium aluminate glasses. Yb3+ improves excitation efficiency at around 980 nm, enhancing emission intensity of Cr4+ fluorescence at 1.2–1.6 μm. Nonradiative energy transfer via electric dipole–dipole interaction between ytterbium and chromium ions was found to be dominant over radiative Yb3+ → Cr4+ energy transfer. A diffusionlimited energy transfer mechanism well explains the decay behavior of Yb3+/Cr4+- codoped glasses. This codoping scheme may be applicable to other Cr4+-containing crystals and glasses.

scholarly journals Combining Hollow Core Photonic Crystal Fibers with Multimode, Solid Core Fiber Couplers through Arc Fusion Splicing for the Miniaturization of Nonlinear Spectroscopy Sensing Devices

Fibers ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 77 ◽  
Author(s):  
Hanna Stawska ◽  
Maciej Popenda ◽  
Elżbieta Bereś-Pawlik
Keyword(s):  
Photonic Bandgap ◽  
Average Power ◽  
Fluorescence Emission ◽  
Nonlinear Spectroscopy ◽  
Fluorescence Emission Spectrum ◽  
Solid Core ◽  
Hollow Core ◽  
Fluorescence Excitation ◽  
Photonic Bandgap Fiber ◽  
Sensing Applications

The presence of fiber optic devices, such as couplers or wavelength division multiplexers, based on hollow-core fibers (HCFs) is still rather uncommon, while such devices can be imagined to greatly increase the potential of HCFs for different applications, such as sensing, nonlinear optics, etc. In this paper, we present a combination of a standard, multimode fiber (MMF) optic coupler with a hollow core photonic bandgap fiber through arc fusion splicing and its application for the purpose of multiphoton spectroscopy. The presented splicing method is of high affordability due to the low cost of arc fusion splicers, and the measured splicing loss (SL) of the HCF-MMF splice is as low as (0.32 ± 0.1) dB, while the splice itself is durable enough to withstand a bending radius (rbend) of 1.8 cm. This resulted in a hybrid between the hollow core photonic bandgap fiber (HCPBF) and MMF coupler, delivering 20 mW of average power and 250-fs short laser pulses to the sample, which was good enough to test the proposed sensor setup in a simple, proof-of-concept multiphoton fluorescence excitation-detection experiment, allowing the successful measurement of the fluorescence emission spectrum of 10−5 M fluorescein solution. In our opinion, the presented results indicate the possibility of creating multi-purpose HCF setups, which would excel in various types of sensing applications.

scholarly journals Luminescent Hybrid Materials Based on Curcumin Derivatives Embedded in Palygorskite

2018 ◽  
Vol 55 (1) ◽  
pp. 63-67
Author(s):  
Monica Florentina Raduly ◽  
Valentin Raditoiu ◽  
Alina Raditoiu ◽  
Luminita Eugenia Wagner ◽  
Viorica Amariutei ◽  
...  
Keyword(s):  
Hybrid Materials ◽  
Fluorescence Spectra ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Hydroxyl Groups ◽  
Fluorescent Properties ◽  
Fluorescence Emission Spectra ◽  
Curcumin Derivatives ◽  
Absorption Studies ◽  
Inorganic Matrix

The seven curcumin derivatives were deposited on palygorskite in order to obtain hybrid materials. The fluorescence emission spectra of the obtained materials show a decrease in fluorescence intensity relative to the respective dyes, due to the environments around the dyestuff molecules created in the host matrices. Absorption studies show the best adsorption on the inorganic matrix, for the compounds with the hydroxyl groups. Correlating fluorescence spectra of hybrid materials with the results for absorption spectra of the dyes adsorbtion on the surface of the clay lead to the conclusion that a high percentage of the adsorbed dye had the effect of fluorescence quenching. Thus, it was confirmed that the fluorescent properties of hybrid materials depend on the interactions established between the fluorescent dyestuff and the inorganic network.

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