scholarly journals Controlled fluorescence in a beetle's photonic structure and its sensitivity to environmentally induced changes

2016 ◽  
Vol 283 (1845) ◽  
pp. 20162334 ◽  
Author(s):  
Sébastien R. Mouchet ◽  
Michaël Lobet ◽  
Branko Kolaric ◽  
Anna M. Kaczmarek ◽  
Rik Van Deun ◽  
...  
Keyword(s):  
Water Immersion ◽  
Fluorescence Emission ◽  
Blue Shift ◽  
Photonic Structure ◽  
Peak Wavelength ◽  
Radiative Relaxation ◽  
Time Resolved ◽  
Fluorescence Measurements ◽  
Reflected Light ◽  
Induced Changes

The scales covering the elytra of the male Hoplia coerulea beetle contain fluorophores embedded within a porous photonic structure. The photonic structure controls both insect colour (reflected light) and fluorescence emission. Herein, the effects of water-induced changes on the fluorescence emission from the beetle were investigated. The fluorescence emission peak wavelength was observed to blue-shift on water immersion of the elytra whereas its reflectance peak wavelength was observed to red-shift. Time-resolved fluorescence measurements, together with optical simulations, confirmed that the radiative emission is controlled by a naturally engineered photonic bandgap while the elytra are in the dry state, whereas non-radiative relaxation pathways dominate the emission response of wet elytra.

Intrinsic fluorescence as a probe of structure-function relationships in Ca2+-transport ATPases

1996 ◽  
Vol 16 (2) ◽  
pp. 87-106 ◽  
Author(s):  
Sérgio T. Ferreira ◽  
Tatiana Coelho-Sampaio
Keyword(s):  
Structure Function ◽  
Conformational Changes ◽  
Fluorescence Emission ◽  
Intrinsic Fluorescence ◽  
Future Prospects ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Fluorescence Measurements ◽  
Transport Atpases ◽  
Functional States

Applications of intrinsic fluorescence measurements in the study of Ca2+-transport ATPases are reviewed. Since the initial reports showing that the fluorescence emission was sensitive to Ca2+ binding, a substantial amount of work has focused on the use of both steady-state and time-resolved fluorescence spectroscopy to investigate structure-function relationships in sarcoplasmic reticulum and plasma membrane Ca2+-ATPases. These studies have revealed ligand-induced conformational changes, as well as provided information on protein-protein, protein-solvent and/or protein-lipid interactions in different functional states of these proteins. The main results of these studies, as well as possible future prospects are discussed.

Binding Properties of Near-IR Dyes to Proteins and Separation of the Dye/Protein Complexes Using Capillary Electrophoresis with Laser-Induced Fluorescence Detection

1996 ◽  
Vol 50 (9) ◽  
pp. 1196-1202 ◽  
Author(s):  
Benjamin L. Legendre ◽  
Steven A. Soper
Keyword(s):  
Capillary Electrophoresis ◽  
Near Infrared ◽  
Protein Complexes ◽  
Fluorescence Emission ◽  
Picosecond Laser ◽  
Laser Fluorescence ◽  
Hydrophobic Core ◽  
Time Resolved ◽  
Nir Dyes ◽  
Fluorescence Measurements

The noncovalent binding of the near-infrared (NIR) dyes, DTTCI (cationic) and IR-125 (anionic), to several model proteins was investigated with the use of steady-state and picosecond laser fluorescence measurements. In an aqueous borate buffer (pH = 9.2), minimal fluorescence emission from these NIR dyes was observed. When a protein was added to the solution, enhancements in the fluorescence emission were found for both dyes. Time-resolved fluorescence measurements for IR-125 in the presence of the protein, β-casein, indicated a biexponential decay with lifetimes of 195 and 682 ps (χ2 = 1.94). Our data suggest that these dyes distribute themselves between the hydrophobic core of the protein and the interstitial aqueous solution. The dye molecules residing in the interior of the protein exhibit enhancements in their fluorescence due to a more favorable microenvironment. The binding and enhanced fluorescence properties allowed the use of these dyes as noncovalent stains for the low-level detection of proteins separated via capillary electrophoresis (CE). Detection limits for some model proteins separated by CE and stained with these NIR dyes were found to be superior to those obtained by using UV detection in CE.

scholarly journals INTERACTION OF COPPER OXIDE NANOPARTICLES WITH BOVINE SERUM ALBUMIN BY SPECTROSCOPIC STUDIES

2018 ◽  
Vol 10 (5) ◽  
pp. 35
Author(s):  
Suja Abraham ◽  
Vellaichamy Parthasarathy
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Fluorescence Intensity ◽  
Bovine Serum ◽  
Structural Changes ◽  
Fluorescence Emission ◽  
Average Particle ◽  
Time Resolved ◽  
Cuo Nps ◽  
Fluorescence Measurements

Objective: Since structural changes of adsorbed protein are necessary for cellular uptake of nanoparticles (NPs) it is of prime importance to know about structural changes of bovine serum albumin (BSA) when it interacts with CuO NPs–a potential new antitumor drug.Methods: CuO NPs prepared by sol-gel technique were characterized by x-ray diffraction (XRD) and tunneling electron microscope (TEM) techniques. The conformational changes induced by CuO NPs on BSA were studied by various spectroscopic techniques such as steady state and time-resolved fluorescence measurements. The changes in fluorescence emission parameters such as fluorescence intensity, fluorescence emission maximum and lifetimes of fluorescent residues in BSA were studied.Results: XRD analysis showed the average particle size as 32 nm. The TEM micrograph showed particles of different size varying from 10 to 45 nm. Fluorescence quenching was confirmed due to a decrease in fluorescence intensity of CuO NPs–BSA complex. The analysis of lifetime measurements indicated BSA contained two tryptophan (trp) residues that fluoresced in different environments. Static quenching mechanism was confirmed by time-resolved measurements when BSA interacted with CuO NPs.Conclusion: Minor structural changes of BSA protein were observed during the interaction studies.

scholarly journals Photophysical properties and fluorosolvatochromism of D–π–A thiophene based derivatives

RSC Advances ◽  
2020 ◽  
Vol 10 (71) ◽  
pp. 43459-43471
Author(s):  
Hussain A. Z. Sabek ◽  
Ahmed M. M. Alazaly ◽  
Dina Salah ◽  
Hesham S. Abdel-Samad ◽  
Mohamed A. Ismail ◽  
...  
Keyword(s):  
Photophysical Properties ◽  
Fluorescence Emission ◽  
Time Resolved ◽  
Time Resolved Spectroscopy ◽  
Solvation Models

Solvation-dependent photophysical properties of two push–pull thiophene-based compounds with donor–π–acceptor (D–π–A) structures were investigated using absorption, fluorescence emission and time resolved spectroscopy, and supported by different solvation models.

scholarly journals Photophysical Properties of Protoporphyrin IX, Pyropheophorbide-a, and Photofrin® in Different Conditions

2021 ◽  
Vol 14 (2) ◽  
pp. 138
Author(s):  
Bauyrzhan Myrzakhmetov ◽  
Philippe Arnoux ◽  
Serge Mordon ◽  
Samir Acherar ◽  
Irina Tsoy ◽  
...  
Keyword(s):  
Singlet Oxygen ◽  
Photophysical Properties ◽  
Protoporphyrin Ix ◽  
Fluorescence Emission ◽  
Solvent Polarity ◽  
Visible Absorption ◽  
Light Dosimetry ◽  
Time Resolved ◽  
Pyropheophorbide A ◽  
Influence Of Solvent

Photodynamic therapy (PDT) is an innovative treatment of malignant or diseased tissues. The effectiveness of PDT depends on light dosimetry, oxygen availability, and properties of the photosensitizer (PS). Depending on the medium, photophysical properties of the PS can change leading to increase or decrease in fluorescence emission and formation of reactive oxygen species (ROS) especially singlet oxygen (1O2). In this study, the influence of solvent polarity, viscosity, concentration, temperature, and pH medium on the photophysical properties of protoporphyrin IX, pyropheophorbide-a, and Photofrin® were investigated by UV-visible absorption, fluorescence emission, singlet oxygen emission, and time-resolved fluorescence spectroscopies.

Efficient control of dye molecules fluorescence in polydopamine via strong optical coupling in a SPASER nanoparticle

2021 ◽  
Author(s):  
Pavel Melentiev ◽  
Boris Khlebtsov ◽  
Anton Gritchenko ◽  
Denis Kudryavtsev ◽  
Igor Ivanov ◽  
...  
Keyword(s):  
Viral Particle ◽  
Direct Detection ◽  
Fluorescence Emission ◽  
Radiative Properties ◽  
Environment Interaction ◽  
Optical Coupling ◽  
Dye Molecules ◽  
Sensing Applications ◽  
Fluorescence Measurements ◽  
Optical Modes

Abstract One of the main approaches of design and manipulation of the quantum emitters’ radiative properties is based on proper control of optical modes of the surrounding quantum emitter environment, leading to, in its ultimate case, to a strong regime of the emitter - environment interaction. In this Letter, we present the realization of a mesoscopic physical system (Au SPASER nanoparticle with polydopamine shell containing dye molecules Cy 7.5) in which the strong optical coupling regime allows: (i) to get rid of dye molecules quenching, (ii) to suppress photobleaching of dye molecules and (iii) to get a great enhancement of dye molecules fluorescence. We have reduced the rate of fluorescence quenching of dye molecules in PDA by 1000 times and increased the fluorescence emission rate of dye molecules by 30 time, thus preparing bright, nanoscale and biocompatible fluorescent probes suitable for bio-sensing applications. As an example of practical use of the probe, we demonstrate direct detection of single SARS-CoV-2 viral particle via fluorescence measurements of the probes attached to the viral particle through the antibodies.

Sign in / Sign up

Export Citation Format

Share Document