scholarly journals Preparation of CdTe/Alginate Textile Fibres with Controllable Fluorescence Emission through a Wet-Spinning Process and Application in the Trace Detection of Hg2+ Ions

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 570 ◽  
Author(s):  
Zhihui Zhao ◽  
Cunzhen Geng ◽  
Xihui Zhao ◽  
Zhixin Xue ◽  
Fengyu Quan ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Resonance Energy Transfer ◽  
Fluorescence Emission ◽  
Resonance Energy ◽  
Coagulation Bath ◽  
Wet Spinning ◽  
Trace Detection ◽  
Metallic Ions ◽  
Textile Fibres ◽  
Cdte Nanocrystals

Fluorescent textile fibres (FTFs) are widely used in many industrial fields. However, in addition to fibres with good fluorescence, fibres with excellent colour controllability, structural stability and appropriate mechanical strength still need to be developed. In this work, CdTe/alginate composite FTFs are prepared by taking advantage of the interactions between CdTe nanocrystals (NCs) and alginate macromolecules via a wet-spinning machine with a CaCl2 aqueous solution as the coagulation bath. CdTe NCs were chemically fixed in the fibre due to the interactions among surface ligands, macromolecules and coagulators (calcium ions), which ensured the excellent dispersity and good stability of the fibres. Förster resonance energy transfer (FRET) between NCs in the fibre was found to be restricted, which means that the emission colour of the fibres was totally controllable and could be predicted. Other properties of alginate fibres, such as flame retardance and mechanical strength, were also well preserved in the fluorescent fibres. Finally, FTFs showed good selectivity toward trace Hg2+ ions over other metallic ions, and the detection could be identified by the naked eye.

scholarly journals Detection of tumor marker miRNA21 based on phosphorescent resonance energy transfer of Mn–ZnS QDs

RSC Advances ◽  
2017 ◽  
Vol 7 (65) ◽  
pp. 41063-41069 ◽  
Author(s):  
Jinzhi Lv ◽  
Yanming Miao ◽  
Guiqin Yan
Keyword(s):  
Energy Transfer ◽  
Tumor Marker ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Human Tumors ◽  
Tumor Diagnosis ◽  
Trace Detection ◽  
Early Tumor

Since miRNA21 is a marker of many human tumors, trace detection of miRNA21 contributes to early tumor diagnosis.

scholarly journals A quantitative protocol for dynamic measurements of protein interactions by Förster resonance energy transfer-sensitized fluorescence emission

2008 ◽  
Vol 6 (suppl_1) ◽  
Author(s):  
A.D Elder ◽  
A Domin ◽  
G.S Kaminski Schierle ◽  
C Lindon ◽  
J Pines ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Protein Interactions ◽  
Imaging Techniques ◽  
Resonance Energy Transfer ◽  
Fluorescence Emission ◽  
Resonance Energy ◽  
Forster Resonance Energy Transfer ◽  
Confocal Imaging ◽  
Förster Resonance Energy Transfer ◽  
Förster Resonance

Fluorescence detection of acceptor molecules sensitized by Förster resonance energy transfer (FRET) is a powerful method to study protein interactions in living cells. The method requires correction for donor spectral bleed-through and acceptor cross-excitation as well as the correct normalization of signals to account for varying fluorophore concentrations and imaging parameters. In this paper, we review different methods for FRET signal normalization and then present a rigorous model for sensitized emission measurements, which is both intuitive to understand and practical to apply. The method is validated by comparison with the acceptor photobleaching and donor lifetime-imaging techniques in live cell samples containing EYFP and ECFP tandem constructs exhibiting known amounts of FRET. By varying the stoichiometry of interaction in a controlled fashion, we show that information on the fractions of interacting donors and acceptors can be recovered. Furthermore, the method is tested by performing measurements on different microscopy platforms in both widefield and confocal imaging modes to show that signals recovered under different imaging conditions are in quantitative agreement. Finally, the method is applied in the study of dynamic interactions in the cyclin–cdk family of proteins in live cells. By normalizing the obtained signals for both acceptor and donor concentrations and using a FRET exhibiting control construct for calibration, stoichiometric changes in these interactions could be visualized in real time. The paper is written to be of practical use to researchers interested in performing sensitized emission measurements. The correct interpretation of the retrieved signals in a biological context is emphasized, and guidelines are given for the practical application of the developed algorithms.

scholarly journals Bioluminescence-Based Energy Transfer Using Semiconductor Quantum Dots as Acceptors

Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2909 ◽  
Author(s):  
Anirban Samanta ◽  
Igor L. Medintz
Keyword(s):  
Quantum Dots ◽  
Energy Transfer ◽  
Organic Dyes ◽  
Stokes Shift ◽  
Resonance Energy Transfer ◽  
Fluorescence Emission ◽  
Resonance Energy ◽  
Semiconductor Quantum Dots ◽  
Renilla Luciferase ◽  
Bioluminescent Protein

Bioluminescence resonance energy transfer (BRET) is the non-radiative transfer of energy from a bioluminescent protein donor to a fluorophore acceptor. It shares all the formalism of Förster resonance energy transfer (FRET) but differs in one key aspect: that the excited donor here is produced by biochemical means and not by an external illumination. Often the choice of BRET source is the bioluminescent protein Renilla luciferase, which catalyzes the oxidation of a substrate, typically coelenterazine, producing an oxidized product in its electronic excited state that, in turn, couples with a proximal fluorophore resulting in a fluorescence emission from the acceptor. The acceptors pertinent to this discussion are semiconductor quantum dots (QDs), which offer some unrivalled photophysical properties. Amongst other advantages, the QD’s large Stokes shift is particularly advantageous as it allows easy and accurate deconstruction of acceptor signal, which is difficult to attain using organic dyes or fluorescent proteins. QD-BRET systems are gaining popularity in non-invasive bioimaging and as probes for biosensing as they don’t require external optical illumination, which dramatically improves the signal-to-noise ratio by avoiding background auto-fluorescence. Despite the additional advantages such systems offer, there are challenges lying ahead that need to be addressed before they are utilized for translational types of research.

Understanding of Förster Resonance Energy Transfer (FRET) in Ionic Materials

2021 ◽  
Vol 2 (4) ◽  
pp. 564-575
Author(s):  
Amanda Jalihal ◽  
Thuy Le ◽  
Samantha Macchi ◽  
Hannah Krehbiel ◽  
Mujeebat Bashiru ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Nile Blue ◽  
Photophysical Properties ◽  
Resonance Energy Transfer ◽  
Fluorescence Emission ◽  
Resonance Energy ◽  
Forster Resonance Energy Transfer ◽  
Förster Resonance Energy Transfer ◽  
Fluorescence Emission Spectrum ◽  
Förster Resonance

Herein, an ionic material (IM) with Förster Resonance Energy Transfer (FRET) characteristics is reported for the first time. The IM is designed by pairing a Nile Blue A cation (NBA+) with an anionic near-infrared (NIR) dye, IR820−, using a facile ion exchange reaction. These two dyes absorb at different wavelength regions. In addition, NBA+ fluorescence emission spectrum overlaps with IR820− absorption spectrum, which is one requirement for the occurrence of the FRET phenomenon. Therefore, the photophysical properties of the IM were studied in detail to investigate the FRET mechanism in IM for potential dye sensitized solar cell (DSSCs) application. Detailed examination of photophysical properties of parent compounds, a mixture of the parent compounds, and the IM revealed that the IM exhibits FRET characteristics, but not the mixture of two dyes. The presence of spectator counterion in the mixture hindered the FRET mechanism while in the IM, both dyes are in close proximity as an ion pair, thus exhibiting FRET. All FRET parameters such as spectral overlap integral, Förster distance, and FRET energy confirm the FRET characteristics of the IM. This article presents a simple synthesis of a compound with FRET properties which can be further used for a variety of applications.

FLUORESCENCE RESONANCE ENERGY TRANSFER BETWEEN DYES AND WATER-SOLUBLE QUANTUM DOTS WITH AVIDIN AS A BRIDGE

2004 ◽  
Vol 03 (03) ◽  
pp. 273-280
Author(s):  
QI-DAN CHEN ◽  
ZHANG-BI LIN ◽  
XING-GUANG SU ◽  
HAO ZHANG ◽  
XIAO-HONG HE ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Energy Transfer ◽  
Fluorescence Resonance Energy Transfer ◽  
Resonance Energy Transfer ◽  
Fluorescence Emission ◽  
Resonance Energy ◽  
Water Soluble ◽  
Fluorescence Emission Spectrum ◽  
Fluorescence Characteristics ◽  
Fluorescence Resonance

3-Mercaptopropyl acid-capped quantum dots (QDs) synthesized in aqueous solution were coupled to avidin-sulforhodamine, also named avidin-Texas red (ATR), via electrostatic attraction. An intensity reduction in the fluorescence emission spectrum of QDs and an enhanced fluorescence intensity of the dye were observed on account of fluorescence resonance energy transfer from the QD donors to the dye acceptors. In addition, the fluorescence characteristics of the QD-ATR conjugates were strongly-related to the quantity of ATR, pH value and ionic strength.

Fluorescence resonance energy transfer-based aptamer biosensors for bisphenol A using lanthanide-doped KGdF4 nanoparticles

2015 ◽  
Vol 7 (12) ◽  
pp. 5186-5192 ◽  
Author(s):  
Nuo Duan ◽  
Hui Zhang ◽  
Yu Nie ◽  
Shijia Wu ◽  
Tingting Miao ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Bisphenol A ◽  
Fluorescence Resonance Energy Transfer ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Trace Detection ◽  
Fluorescence Resonance

FRET from KGdF4:Tb3+ NP–aptamers to AuNP–cDNA for the trace detection of BPA.

scholarly journals Solid state fluorescence of proteins in high throughput mode and its applications

F1000Research ◽  
2019 ◽  
Vol 2 ◽  
pp. 82
Author(s):  
Saurabh Gautam ◽  
Munishwar N Gupta
Keyword(s):  
Solid State ◽  
High Throughput ◽  
Fluorescence Spectra ◽  
Fluorescent Protein ◽  
Resonance Energy Transfer ◽  
Fluorescence Emission ◽  
Resonance Energy ◽  
Emission Spectra ◽  
Fluorescence Emission Spectra ◽  
Simple Method

Direct comparison between fluorescence spectra of a sample in solution and solid state form is valuable to monitor the changes in protein structure when it is “dried” or immobilized on a solid surface (for biocatalysis or sensor applications). We describe here a simple method for recording fluorescence emission spectra of protein powders without using any dedicated accessory for solid samples in a high-throughput format. The 96-well plate used in our studies, was coated black from all the sides and the excitation and emission paths are identical and are from the top of the well. These two features minimize scatter and provide fairly noise free spectra. Even then the fluorescence intensity may be dependent upon many factors such as the extent of protein aggregation, morphology and sizes of the protein particles. Hence, (changes in) λmax emission may be a more reliable metric in the case of fluorescence spectra of proteins in the solid state. However, any large changes in the intensity could indicate changes in the microenvironment of the fluorophore. The fluorescence emission spectra were blue-shifted (4 to 9 nm), showed an increase in the intensity for different proteins studied upon lyophilization, and were similar to what has been reported by others using available commercial accessories for solid state samples. After validating that our method worked just as well as the dedicated accessories, we applied the method to compare the fluorescence emission spectra of α-chymotrypsin in solution, precipitated form, and the lyophilized powder form. We further examined the fluorescence emission spectra of green fluorescent protein (GFP) in solution and solid form. We also analyzed fluorescence resonance energy transfer (FRET) between tryptophan (Trp57) and the cyclic chromophore of GFP. These findings pointed towards the change in the microenvironment around the cyclic chromophore in GFP upon lyophilization.

scholarly journals A Ratiometric Fluorescent Aptamer Homogeneous Biosensor Based on Hairpin Structure Aptamer for AFB1 Detection

2022 ◽  
Author(s):  
Beibei Feng ◽  
Fei Zhao ◽  
Min Wei ◽  
Yong Liu ◽  
Xinyu Ren ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Resonance Energy Transfer ◽  
Fluorescence Emission ◽  
Resonance Energy ◽  
Hairpin Structure ◽  
Fluorescence Signal ◽  
Detection Range ◽  
Quenching Effect ◽  
Double Stranded Dna ◽  
Aflatoxin B

Abstract On the basis of aptamer (Apt) with hairpin structure and fluorescence resonance energy transfer (FRET), a ratio fluorescent aptamer homogeneous sensor was prepared for the determination of Aflatoxin B1 (AFB1). Initially, the Apt labeled simultaneously with Cy5, BHQ2, and cDNA labeled with Cy3 were formed a double-stranded DNA through complementary base pairing. The fluorescent aptamer sensor demonstrates a weak fluorescence emission of Cy3 and a high fluorescence emission of Cy5 due to the quenching effect of BHQ2. The double-stranded DNA structure will be disintegrated in the presence of AFB1, resulting the removal of Cy3 and the close of Cy5 with BHQ2. The fluorescence signal of Cy3 and Cy5 were restored and quenched respectively. Thus, the ratio change of FCy3 to FCy5 was used to realized the detection of AFB1 with wider detection range and lower limit of detection (LOD). The response of the optimized protocol for AFB1 detection was wider linear range from 0.05 ng/mL to 100 ng/mL and the LOD was 12.6 pg/mL. The sensor designed in this strategy has the advantages of simple preparation and fast signal response. It has been used for the detection of AFB1 in labeled corn and wine, indicating it had good application potential in practical samples.

Abstract 802: Dynamic FRET-Based Ca-Calmodulin Measurements in Intact Ventricular Myocytes Uncover Differential Signal Integration Due to Ca-Calmodulin Affinity

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Qiujing Song ◽  
Julie Bossuyt ◽  
Jeffrey Saucerman ◽  
Donald Bers
Keyword(s):  
Ventricular Myocytes ◽  
Resonance Energy Transfer ◽  
Fluorescence Emission ◽  
Resonance Energy ◽  
Adult Rabbit ◽  
Signal Integration ◽  
Differential Signal ◽  
Time To Peak ◽  
Cardiac Functions ◽  
Rabbit Ventricular Myocytes

Background: Myocyte [Ca] i varies beat-to-beat and calmodulin (CaM) transduces Ca signals to regulate many cardiac functions (e.g. via CaM-dependent kinase, CaMKII, and calcineurin, CaN). We hypothesize that the different Ca-CaM affinities of CaMKII (Kd ∼45 nM) and CaN (Kd ∼2 nM) will dictate their dynamic and tonic binding to Ca-CaM. Methods: Two adenoviral vectors encoding FRET (fluorescence resonance energy transfer) based biosensors with affinities similar to CaMKII and CaN (BsCaM-45 vs. BsCaM-2) were generated to monitor Ca-CaM dynamics in adult rabbit ventricular myocytes (with extra CaM expression via adenovirus). Results: Ca-CaM binding reduces FRET and increases the fluorescence emission ratio (F 480 /F 530 ). Figure shows the lower affinity sensor BsCaM-45 (like CaMKII) turns on and off completely with only slight diastolic increase at 1.0 Hz (5% ± 2.5%, vs. 0.1 Hz, n = 5). In contrast, the higher affinity sensor BsCaM-2 (like CaN) showed significant diastolic signal integration at 1.0 Hz (20% ± 3%, n = 5, p < 0.05). BsCaM-2 (n = 5) has slower kinetics vs. BsCaM-45 (n = 5): at 1.0 Hz, time to peak: 218 ± 11 vs. 244 ± 15 ms, ns; τ-decay: 647 ± 17 vs. 321 ± 25 ms, p < 0.05). Conclusion: CaM target proteins with different affinities (like CaMKII and CaN) respond very differently to the same Ca signal, (integrating vs. phasic), presumably tuned appropriately for their signaling pathway. This dynamic response shapes subsequent cellular processes in the heart. Indeed, altered diastolic [Ca] i or heart rate (as in pathophysiological states) can differentially influence downstream CaM-dependent pathways. Beat-to-beat FRET signal changes in Rabbit Ventricular Myocytes

Sign in / Sign up

Export Citation Format

Share Document