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‘Luminescent carbon nanodots: Current prospects on synthesis, properties and sensing applications’ Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2021-01-09 Nagaraju Kottam and Smrithi S P
‘Nanocarbon science’ ignited interest owing to its substantial scope in biomedicine, energy and environment-beneficial applications. Carbon dots (C-dots), a multi-faceted nanocarbon material, emerged as a homologue to graphene and henceforth geared extensive investigation both on its properties and applications. Eximious properties like excitation-wavelength tunable fluorescence emission, up-converted
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Perfusion fixation methods for preclinical biodistribution studies: A comparative assessment using automated image processing Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2021-01-09 Rania Belhadjhamida, Harriet Lea-Banks and Kullervo Hynynen
Studying the biodistribution of novel therapeutics and biomaterials in vivo requires effective and consistent perfusion and fixation of major organs. Standard methods for removing red blood cells (RBCs) and fixing tissue often involve transcardial perfusion, such as brain-targeted perfusion (via the left ventricle) or lung-targeted perfusion (via the right ventricle). Using autofluorescence measurements
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Large Stokes-shift bioorthogonal probes for STED, 2P-STED and multi-color STED nanoscopy Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2021-01-09 György Török, Gergely B Cserép, András Telek, Dóra Arany, Melinda Váradi, László Homolya, Miklós Kellermayer, Péter Kele and Krisztina Németh
Synthesis and multiple STED imaging applications of four, red-emitting (610–670 nm), tetrazine-functionalized fluorescent probes ( CBRD = Chemical Biology Research group Dye 1–4 ) with large Stokes-shift is presented. Present studies revealed the super-resolution microscopy applicability of the probes as demonstrated through bioorthogonal labeling scheme of cytoskeletal proteins actin and keratin-19
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The phasor FLIM method reveals a link between a change in energy metabolism and mHtt protein spread in healthy Mammalian cells when co-cultured with Huntington diseased cells Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2021-01-09 Sara Sameni, Run Zhang and Michelle A Digman
Huntington Disease (HD) is a late-onset autosomal neurodegenerative disease characterized by the aggregations of mutant Huntingtin proteins (mHTT). A glutamine stretch (PolyQ) at the N-terminal of the Huntingtin protein is generated by the abnormal expansion of CAG trinucleotide repeats in exon 1 of the HTT gene. While the resulting polyQ aggregates are the predominate feature of HD, the intercellular
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Study on the fluorescence of double-emission carbon quantum dots by improved intercept method Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2021-01-09 ZhiKun Gao, Tongfan Hao, Qunxiang Fang, Changchun Wu and Zhiping Zhou
The fluorescence mechanism of dual-emission carbon quantum dots (DCQDs) is investigated by the improved intercept method, of which the DCQDs with high quantum yield are synthesized by hydrothermal method by using the precursor of sulfadiazine. The research of the morphology, chemical properties and fluorescence properties on DCQDs, shows that DCQDs have graphene-like structure and well-resolved lattice
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Cumulative effects of photobleaching in volumetric STED imaging—artefacts and possible benefits Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2021-01-09 Chinmaya Venugopal Srambickal, Jan Bergstrand and Jerker Widengren
In stimulated emission depletion (STED) imaging, the excitation and depletion laser beams extend well beyond the focal plane in the imaged sample. We investigated how photobleaching resulting from this irradiation can affect STED images, by acquiring 3D images of fluorescent polystyrene beads using a 2D STED microscope, and applying different Z pixel sizes, scanning speeds, resulting in different laser
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Rapid (FLASH-FLIM) imaging of protoporphyrin IX in a lipid mixture using a CMOS based widefield fluorescence lifetime imaging camera in real time for margin demarcation applications Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2021-01-09 Kulwinder Sagoo, Nathan Cumberbatch, Adam Holland and Graham Hungerford
The fluorescence from protoporphyrin IX (PpIX) has been employed to characterise cellular activity and assist in the visualisation of tumour cells. Its formation can be induced by 5-aminolevulonic acid (5-ALA) which is metabolised by tumour cells to form PpIX. The PpIX is localised within the cells, rather than spreading into the vascular system. This, plus its photophysics, exhibits potential in photodynamic
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Non-covalent binding and selective fluorescent sensing of dipyrone with a carbocyanine dye and cetyltrimethylammonium bromide Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2021-01-09 Sofia A Zakharenkova, Anna S Kriveleva, Ekaterina A Katkova, Irina A Doroshenko, Nikolai Yu Polovkov, Tatyana A Podrugina and Mikhail K Beklemishev
The work is aimed at the search of selective fluorescent sensors without using specific artificial receptors, antibodies, enzymes etc. With this end in view, methods based on non-covalent binding of target analytes are sought. We observed dramatic changes in the emission spectrum of a carbocyanine dye in a micellar surfactant solution (cetyltrimethylammonium bromide, CTAB) in the presence of dipyrone
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Zinc metal–organic framework with 3-pyridinecarboxaldehyde and trimesic acid as co-ligands for selective detection of Cr (VI) ions in aqueous solution Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-10-05 Enoch K Adotey, Mehdi Amouei Torkmahalleh and Mannix P Balanay
There is an increasing need for the development of probes for the detection of hexavalent chromium since it is a known carcinogen, which can cause adverse effects on human health. Metal-organic frameworks (MOFs) have shown successful detection and removal of hazardous substances from aqueous media. This work presents the use of simple organic ligands such as 3-pyridinecarboxaldehyde and trimesic acid
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Evaluation of the acidic strengths on electronic ground and excited states of proton transfer dye using Excitation-Emission fluorescence matrix (EEM) and Multivariate Curve Resolution with Alternating Least Squares (MCR-ALS) Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-10-05 Willian Francisco Cordeiro Dantas, Luís Gustavo Teixeira Alves Duarte, Fabiano Severo Rodembusch, Ronei Jesus Poppi and Teresa Dib Zambon Atvars
Multivariate Curve Resolution with Alternating Least Squares (MCR-ALS) was for the first time successfully used to evaluate an intricate photophysical behavior, where deprotonation on the electronic ground state (S 0 ), intra and intermolecular proton transfer processes (ESPT and ESIPT) on the electronic excited state (S 1 ) can simultaneously be presented. In this sense, the organic dye 2-(2′-hyd
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Real-time fluorescence sensing of single photoactive proteins using silver nanowires Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-10-05 Karolina Sulowska, Kamil Wiwatowski, Maciej Ćwierzona, Joanna Niedziółka-Jönsson and Sebastian Maćkowski
We demonstrate that single functionalized silver nanowires form a geometric platform suitable for efficient real-time detection of single photoactive proteins. By collecting series of images using wide-field fluorescence microscopy, events of single protein attachment can be distinguished with the signal to noise ratio further improved by fluorescence enhancement due to plasmon excitations in the nanowires
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Light management using CsPbBr3colloidal quantum dots for luminescent solar concentrators. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-10-05 Akhilesh K Singh
CsPbBr 3 colloidal quantum dots have been synthesized by hot-injection method showing spherical shape with an average diameter of ∼10.5 nm. UV–vis absorption of CsPbBr 3 colloidal quantum dots shows a broad spectrum with an optical bandgap of ∼2.3682 eV. The steady-state photoluminescence measurement reveals a narrow emission peak at 2.352 eV with full-width at half maximum of 0.113 eV. Absolute photoluminescence
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Evaluating spectral overlap with the degree of quenching in UCP luminescence energy transfer systems. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-10-05 Letitia Burgess,Hannah Wilson,Alex R Jones,Sam Hay,Louise Natrajan
The use of organic based fluorophores has been firmly established as a key tool in the biological sciences, with many biological-sensing methods taking advantage of Förster Resonance Energy Transfer (FRET) between different fluorescent organic based dyes following one photon excitation. Nevertheless, the employment of UV-visible absorbing dyes as fluorescent tags and markers typically suffer from several
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Activity of carbonyl cyanide-3-chlorophenylhydrazone on biofilm formation and antimicrobial resistance inPseudomonas aeruginosausing quantum dots-meropenem conjugates as nanotools. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-10-05 Valdemir Vicente Silva JÚnior,Bruno Raposo,Ana Catarina S Lopes,Paulo S R Araújo,Adriana Fontes,Paulo Euzebio Cabral Filho,Maria Amélia V Maciel
Hospital infections associated with multidrug-resistant (MDR) Pseudomonas aeruginosa are a worldwide public health problem. Efflux systems and biofilm formation are mechanisms related to resistance to carbapenemics. In this study, quantum dots (QDs) were used to evaluate the effect of carbonyl cyanide-3-chlorophenylhydrazone (CCCP), an efflux pump system inhibitor, on biofilm formation and antimicrobial
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Determination of Fluorescence Quantum Yields in Scattering Media. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-10-05 María Gabriela Lagorio
The fluorescence quantum yield is a measure of the efficiency of photon emission and quantifies the luminescent performance of a given sample. The determination of fluorescence quantum yields, particularly in scattering media, is relevant in the areas of materials science, technology and photonics. It is equally crucial when studying fluorescent bioanalytical probes and biological systems either for
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Diphenylalanin nanofibers-inspired synthesis of fluorescent gold nanoclusters for screening of anti-amyloid drugs. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-07-27 Tayebeh Zohrabi,Amir Amiri-Sadeghan,Mohammad Reza Ganjali,Saman Hosseinkhani
Protein misfolding and aggregation into amyloid structures is linked with a number of pathophysiological disorders. In the past decade, significant progresses have been made in the drug discovery strategies against toxic aggregates. Although lack of specificity and high sensitivity for in vitro screening system still seen. Here we demonstrate a new targeting probe based on FF diphenylalanine peptide
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Thioflavin T as a noncovalent reporter for a label-free, non-enzymatic, catalytic DNA amplifier. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-07-19 Tulsi R Damase,Md Mamunul Islam,Mason Shipley,Peter B Allen
DNA-DNA reactions can be monitored with a label-free fluorogenic reaction. Guanosine-rich, single-stranded DNA oligonucleotides bind to thioflavin-T (ThT) and enhance the fluorescence of the dye. We discovered a novel DNA sequence that produces fluorescence upon binding to ThT. We denote this oligonucleotide ThTSignal. We use ThTSignal as a label-free reporter for the activity of several designed DNA-DNA
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Spectrofluorometer: the excitation beam intensity calibration using a single standard solution. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-07-19 Krzysztof Nawara,Jacek Waluk
The accurate, periodically updated excitation beam intensity correction is essential for conducting fluorescence spectroscopy research. This article describes a simple and inexpensive approach to reevaluate the excitation calibration curve of a spectrofluorometer using a single dye solution. The method shows excellent agreement with the data obtained using a certified calibration detector for the broad
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Quo vadis FRET? Förster's method in the era of superresolution. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-07-06 Ágnes Szabó,Tímea Szendi-Szatmári,János Szöllősi,Peter Nagy
Although the theoretical foundations of Förster resonance energy transfer (FRET) were laid in the 1940s as part of the quantum physical revolution of the 20th century, it was only in the 1970s that it made its way to biology as a result of the availability of suitable measuring and labeling technologies. Thanks to its ease of application, FRET became widely used for studying molecular associations
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A sensitive near infrared to near-infrared luminescence nanothermometer based on triple doped Ln -Y2O3. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-07-06 Ioana Porosnicu,Claudiu Colbea,Flaviu Baiasu,Mihail Lungu,Marian Cosmin Istrate,Daniel Avram,Carmen Tiseanu
In recent years, luminescence nanothermometers with near infrared light (NIR) emission excited in the NIR range have attracted much attention due to their potential in bio applications. Here, we propose a new nanothermometer based on triple doped 1%Ho, 1%Er, 1%Yb - Y 2 O 3 that operates in the second and third biological windows around 1200 and 1530 nm under pulsed excitation at 905 nm. The NIR emissions
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Single-molecule chemistry. Part I: monitoring oxidation of G in oligonucleotides using CY3 fluorescence. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-07-06 Jens Sobek,Marco Schmidt,Jonas Grossmann,Hubert Rehrauer,Lucas Schmidt,Ralph Schlapbach
Single-molecule hybridisation of CY3 dye labelled short oligonucleotides to surface immobilised probes was investigated in zero-mode waveguide nanostructures using a modified DNA sequencer. At longer measuring times, we observed changes of the initial hybridisation fluorescence pulse pattern which we attribute to products created by chemical reactions at the nucleobases. The origin is a charge separated
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Using in vivo multiphoton fluorescence lifetime imaging to unravel disease-specific changes in the liver redox state. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-07-06 Deborah S Barkauskas,Gregory Medley,Xiaowen Liang,Yousuf H Mohammed,Camilla A Thorling,Haolu Wang,Michael S Roberts
Multiphoton fluorescence lifetime microscopy has revolutionized studies of pathophysiological and xenobiotic dynamics, enabling the spatial and temporal quantification of these processes in intact organs in vivo . We have previously used multiphoton fluorescence lifetime microscopy to characterise the morphology and amplitude weighted mean fluorescence lifetime of the endogenous fluorescent metabolic
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Evaluating spectral overlap with the degree of quenching in UCP luminescence energy transfer systems Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-07-06
Description unavailable
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A luminescent solar concentrator ray tracing simulator with a graphical user interface: features and applications. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-07-06 Bolong Zhang,Hanbo Yang,Timothy Warner,Paul Mulvaney,Gary Rosengarten,Wallace W H Wong,Kenneth P Ghiggino
A Monte-Carlo ray tracing simulator with a graphical user interface (MCRTS-GUI) has been developed to provide a quantitative description, performance evaluation and photon loss analysis of luminescent solar concentrators (LSCs). The algorithm is applied to several practical LSC device structures including multiple dyes in the same waveguiding layer, and structures where a dye layer is sandwiched between
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Bauhinia monandra leaf lectin (BmoLL) conjugated with quantum dots as fluorescent nanoprobes for biological studies: application to red blood cells. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-07-06 Weslley F Oliveira,Natália R M Santos,Mariana P Cabrera,Sílvio A O Ferreira,Bruno L Raposo,Thiago H Napoleão,Patrícia M G Paiva,Luana C B B Coelho,Paulo E Cabral Filho,Adriana Fontes,Maria T S Correia
Carbohydrates perform important physiological functions in eukaryotic and prokaryotic cells. Indeed, alterations in glycan patterns may be associated with disorders. The analysis of these sugars can be reached using nanoprobes composed by lectins associated with fluorescent nanoparticles. This study reports the conjugation of a galactose-binding lectin (BmoLL) isolated from Bauhinia monandra leaves
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Proposal for simultaneous analysis of fluorescence intensity fluctuations and resonance energy transfer (IFRET) measurements. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-07-06 Michael R Stoneman,Gabriel Biener,Valerică Raicu
Resonance energy transfer (RET) and fluorescence fluctuation spectroscopies (FFS) are powerful fluorescence-based techniques for quantifying the self-association of membrane receptors within oligomeric complexes in living cells. However, RET spectrometry’s ability to extract information on the detailed quaternary structure of oligomers sometimes rests on assumptions regarding the relative abundances
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Fluorescent β-ketoenole AmyGreen dye for visualization of amyloid components of bacterial biofilms. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-07-06 Olena Moshynets,Svitlana Chernii,Viktor Chernii,Mykhaylo Losytskyy,Serhii Karakhim,Rafal Czerwieniec,Vasyl Pekhnyo,Sergiy Yarmoluk,Vladyslava Kovalska
Green-emitting water-soluble amino-ketoenole dye AmyGreen is proposed as an efficient fluorescent stain for visualization of bacterial amyloids in biofilms and the detection of pathological amyloids in vitro . This dye is almost non-fluorescent in solution, displays strong green emission in the presence of amyloid fibril of proteins. AmyGreen is also weakly fluorescent in presence to biomolecules that
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Kappaphobia is the elephant in the fret room. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-07-06 B Wieb VanDerMeer
FRET is both a phenomenon and a spectroscopic technique, capable of measuring one geometric quantity: kappa-squared divided by the sixth power of the donor-acceptor distance. Kappa-squared is often replaced by a constant even though such a replacement may lead to serious errors. Kappaphobia, the fear of kappa or the reluctance to deal with kappa-squared adequately, is a looming presence in the FRET
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On the origin and correction for inner filter effects in fluorescence Part I: primary inner filter effect-the proper approach for sample absorbance correction. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-05-31 Joseph Kimball,Jose Chavez,Luca Ceresa,Emma Kitchner,Zhangatay Nurekeyev,Hung Doan,Mariusz Szabelski,Julian Borejdo,Ignacy Gryczynski,Zygmunt Gryczynski
Fluorescence technologies have been the preferred method for detection, analytical sensing, medical diagnostics, biotechnology, imaging, and gene expression for many years. Fluorescence becomes essential for studying molecular processes with high specificity and sensitivity through a variety of biological processes. A significant problem for practical fluorescence applications is the apparent non-linearity
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Synthesis of amphoteric fluorescent copolymers: materials exhibiting multicolor photophysical properties. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-05-31 Jie Jiang,Guoping Zu,Yuzhong Shi,Xin Liu,Xuefeng Wang,Xiaorong Wang
Six emissive amphoteric copolymers were prepared and characterized ( 1 H NMR, DSC, steady-state UV–vis, and emission spectroscopy) in the paper. A system of multi-color emitters, composed of P1 (green and yellow), P2 (green), P3 (red), P4 (blue), P5 (yellow) and P6 (green and yellow), were presented. P5 showed multicolor fluorescence that belonged to the color-specially emissive system at different
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Anionic Quantum Dots reveal actin-microridges in zebrafish epidermis. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-05-20 Valeria Sigot,Paulo E Cabral Filho,María F Sampedro,Beate S Santos,Adriana Fontes
Enhancement of hydrophilicity and functionalization of CdTe QDs (Quantum Dots) via surface modifications have made them suitable to be used as specific probes for cell imaging. Applications for targeting cell surfaces have been widely demonstrated in vitro but their use in animal models is not trivial. Here, we reported the interaction of mercaptosuccinic-coated (MSA) CdTe QDs with the epidermis of
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Photoactivatable fluorophores for single-molecule localization microscopy of live cells. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-05-20 Yang Zhang,Françisco M Raymo
Photochemical reactions can be designed to convert either irreversibly or reversibly a nonemissive reactant into an emissive product. The irreversible disconnection of a photocleavable group from an emissive chromophore or the reversible interconversion of a photochromic component is generally exploited to implement these operating principles for fluorescence switching. In both instances, the interplay
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Simultaneous fluorescence and quantitative phase imaging of MG63 osteosarcoma cells to monitor morphological changes with time using partially spatially coherent light source. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-05-20 Shilpa Tayal,Veena Singh,Tejinder Kaur,Neetu Singh,Dalip Singh Mehta
Quantitative phase imaging (QPI) technique is used to determine various biophysical parameters, such as refractive index, cell thickness, morphology, etc. On the other hand, fluorescence microscopy is used to acquire information regarding molecular specificity of the biological cells and tissues. Conventionally, a fully coherent light source such as laser is used in QPI technique to obtain the interference
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Review: Clinical in vivo multiphoton FLIM tomography. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-04-22 Karsten König
Fluorescence Lifetime Imaging (FLIM) in life sciences based on ultrashort laser scanning microscopy and time-correlated single photon counting (TCSPC) started 30 years ago in Jena/East-Germany. One decade later, first two-photon FLIM images of a human finger were taken with a lab microscope based on a tunable femtosecond Ti:sapphire laser. In 2002/2003, first clinical non-invasive two-photon FLIM studies
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Multi-site probe for selective turn-on fluorescent detection of Al(III) in aqueous solution: synthesis, cation binding, mode of coordination, logic gate and cell imaging. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-04-22 G Mahalakshmi,P Saravana Kumar,K N Vennila,G Sivaraman,M Seenivasaperumal,Kuppanagounder P Elango
An easy to make organic probe (hereafter called as R) possessing multiple ligating sites have been synthesized and characterized using spectral techniques. The probe exhibits selective and sensitive turn-on fluorescence response with Al(III) in aqueous dimethylformamide (DMF) (1:1 v/v) solution. Fluorescence titration experiment shows that the probe binds with Al(III) with a 1:1 stoichiometry and a
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Ba5Zn4Gd8O21:Tb3+-structural characterization and the Judd-Ofelt parameterization from emission spectra. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-04-22 Jyoti Dalal,Mandeep Dalal,Sushma Devi,Sangeeta Chahar,Anju Hooda,Avni Khatkar,R K Malik,V B Taxak,S P Khatkar
Ba5Zn4Gd8O21:Tb3+ nanorods; synthesized via solution combustion route; were found to crystallize in the tetragonal (I4/m, 87) crystal system. The UV excitation at 290 nm of all Ba5Zn4Gd8O21:Tb3+ samples yielded the characteristics emission corresponding to 5D4 → 7F6,5,4,3 transitions in Tb3+ activator (used for Judd-Ofelt analysis). A detailed investigation of photoluminescence decay curves and emission
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Tutorial: measurement of fluorescence spectra and determination of relative fluorescence quantum yields of transparent samples. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-04-22 Marcia Levitus
The measurement of fluorescence spectra and the determination of fluorescence quantum yields in transparent samples are conceptually simple tasks, but these procedures are subject to several pitfalls that can lead to significant errors. Available technical reports and protocols often assume that the reader possesses a solid theoretical background in spectroscopy and has ample experience with fluorescence
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Resolution of 4 components in the same pixel in FLIM images using the phasor approach Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-04-14 Alexander Vallmitjana, Alexander Dvornikov, Belen Torrado, David M Jameson, Suman Ranjit and Enrico Gratton
In several cellular systems, the phasor FLIM approach has shown the existence of more than 2 components in the same pixel, a typical example being free and bound NADH. In order to properly quantify the concentrations and the spatial distributions of fluorescence components associated with different molecular species we developed a general method to resolve 3 and 4 components in the same pixel using
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A rapid analysis platform for investigating the cellular locations of bacteria using two-photon fluorescence lifetime imaging microscopy Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-04-14 Natakorn Sapermsap, David Day-Uei Li, Ryath Al-Hemedawi, Yahui Li, Jun Yu, David JS Birch and Yu Chen
Facultative intracellular pathogens are able to live inside and outside host cells. It is highly desirable to differentiate their cellular locations for the purposes of fundamental research and clinical applications. In this work, we developed a novel analysis platform that allows users to choose two analysis models: amplitude weighted lifetime ( τ A ) and intensity weighted lifetime ( τ I ) for fluorescence
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High resolution mapping of subcellular refractive index by Fluorescence Lifetime Imaging: a next frontier in quantitative cell science? Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-04-14 Artem Pliss and Paras N Prasad
Intracellular refractive index (RI) is an essential biophysical parameter, which best represents the mass and the distribution of proteins in the cell interior, including high-density accumulations in membraneless organelles. For RI measurements, a number of sophisticated techniques have been developed; however most of the new approaches are either insufficiently sensitive to intracellular variations
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Fluorescence turn off-on probe (β-cyclodextrin-hydroxyquinoline) for monitoring of Cd2+ ions and tetracycline. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-04-01 Samaneh Nazerdeylami,Jahan B Ghasemi,Ahmad Amiri,Ghodsi Mohammadi Ziarani,Alireza Badiei
In this paper, a photoluminescent turn off-on switch probe β-cyclodextrin-hydroxyquinoline (β-CD-HQ) was efficiently applied for detection and measurement of Cd2+ ions and detection of tetracycline. The proposed assay has shown an excellent selective fluorescence response toward Cd2+ ions over other ions like Al3+, Pb2+, Zn2+, Co2+, K+, Na+ and Sr2+. The fluorescence emission intensity of the probe
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High Temporal Resolution and Polarization Resolved Fluorescence Lifetime Measurements through Stimulated Emission. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-03-23 Khalil Ur Rehman,Subir Das,Yih-Fan Chen,Fu-Jen Kao
We have implemented polarization-resolved fluorescence lifetime measurement through stimulated emission based pump-probe technique, which promises much higher temporal resolution (~4 ps) than conventional time-correlated single-photon counting. The depolarization of ATTO 647N fluorescent dye is resolved through anisotropy fluorescence lifetime measurements, with variable time delay introduced between
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Spatial filter and its application in three-dimensional single molecule localization microscopy Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-03-19 Xiaoming Fan, Johnny Hendriks, Maddalena Comini, Alexandros Katranidis, Georg Büldt and Thomas Gensch
Single molecule localization microscopy (SMLM) allows the imaging of cellular structures with resolutions five to ten times below the diffraction limit of optical microscopy. It was originally introduced as a two-dimensional technique based on the localization of single emitters as projection onto the x-y imaging plane. The determination of the axial position of a fluorescent emitter is only possible
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Advantages and limitations of a supernegative GFP in facilitating MyoD intracellular tracking Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-03-13 Lucia Boeri, Emanuela Jacchetti, Monica Soncini, Alessandro Negro, Diego Albani and Manuela Teresa Raimondi
Despite intracellular molecular dynamics being fundamental to understand pathological, biomechanical or biochemical events, several processes are still not clear because of the difficulty of monitoring and measuring these phenomena. To engineer an effective fluorescent tool useful to improve protein intracellular tracking studies, we fused a supernegative green fluorescent protein, (−30)GFP, to a myogenic
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An eco-friendly fluorometric polymer nanoparticle for selectively monitoring sulfadiazine in tap water. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-03-02 Zhikun Gao,Yu Luan,Yunfei Cao,Jialin Li,Yi Lu,Tianshu Liu,Ningwei Wang,Zhiping Zhou,Weihong Huang,Wanzhen Xu
An eco-friendly fluorescence polymer nanoparticle based on carbon quantum dots and poly(methyl methacrylate) nanoparticles is successfully fabricated to detect sulfadiazine. By making use of the abundant functional group of carbon quantum dots and poly(methyl methacrylate) nanoparticles, without any extra modification, the synthetic process of the fluorescence nanoparticles is reduced and the unnecessary
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Time-resolved endogenous chlorophyll fluorescence sensitivity to pH: study on Chlorella sp. algae. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-03-02 A Marcek Chorvatova,M Uherek,A Mateasik,D Chorvat
To better understand pH-dependence of endogenous fluorescence of algae, we employed spectroscopy and microscopy methods, including advanced time-resolved fluorescence imaging microscopy (FLIM), using green algae Chlorella sp. as a model system. Absorption spectra confirmed two peaks, at 400-420 nm and 670 nm. Emission was maximal at 680 nm, with smaller peaks between 520 and 540 nm. Acidification led
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Optimization of upconversion luminescence excitation mode for deeper in vivo bioimaging without contrast loss or overheating. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-03-02 Daria V Pominova,Igor D Romanishkin,Vera Yu Proydakova,Pavel V Grachev,Arkadiy S Moskalev,Anastasia V Ryabova,Vladimir I Makarov,Kirill G Linkov,Sergei V Kuznetsov,Valerii V Voronov,Oleg V Uvarov,Victor B Loschenov
Upconversion nanoparticles have attracted considerable attention as luminescent markers for bioimaging and sensing due to their capability to convert near-infrared (NIR) excitation into visible or NIR luminescence. However, the wavelength of about 970 nm is commonly used for the upconversion luminescence excitation, where the strong absorption of water is observed, which can lead to laser-induced overheating
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Automated screening of AURKA activity based on a genetically encoded FRET biosensor using fluorescence lifetime imaging microscopy. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-02-20 Florian Sizaire,Gilles Le Marchand,Jacques Pécréaux,Otmane Bouchareb,Marc Tramier
Fluorescence Lifetime Imaging Microscopy (FLIM) is a robust tool to measure Förster Resonance Energy Transfer (FRET) between two fluorescent proteins, mainly when using genetically-encoded FRET biosensors. It is then possible to monitor biological processes such as kinase activity with a good spatiotemporal resolution and accuracy. Therefore, it is of interest to improve this methodology for future
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High-throughput, multi-parametric, and correlative fluorescence lifetime imaging. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-02-20 Chetan Poudel,Ioanna Mela,Clemens F Kaminski
In this review, we discuss methods and advancements in fluorescence lifetime imaging microscopy that permit measurements to be performed at faster speed and higher resolution than previously possible. We review fast single-photon timing technologies and the use of parallelized detection schemes to enable high-throughput and high content imaging applications. We appraise different technological implementations
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Photobleaching of organic fluorophores: quantitative characterization, mechanisms, protection. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-02-20 Alexander P Demchenko
Photochemical stability is one of the most important parameters that determine the usefulness of organic dyes in different applications. This Review addresses key factors that determine the dye photostability. It is shown that photodegradation can follow different oxygen-dependent and oxygen-independent mechanisms and may involve both 1S1-3T1 and higher-energy 1Sn-3Tn excited states. Their involvement
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Tunable white emission of silver-sulfur-zeolites as single-phase LED phosphors. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-02-19 Wouter Baekelant,Giacomo Romolini,Li Sun,Michiel De Ras,Eduard Fron,Tiago Moreira,Catarina Viola,Andreia Ruivo,César A T Laia,Johan Martens,Cristina Martin,Cheol Woong Kim,Mark van der Auweraer,Maarten B J Roeffaers,Johan Hofkens,Eduardo Coutino-Gonzalez
Metal clusters confined inside zeolite materials display remarkable luminescent properties, making them very suitable as potential alternative phosphors in white LED applications. However, up to date, only single-color emitters have been reported for luminescent metal-exchanged zeolites. In this study, we synthesized and characterized white emitting silver-sulfur zeolites, which show a remarkable color
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Precisely calibrated and spatially informed illumination for conventional fluorescence and improved PALM imaging applications. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-02-19 Angel Mancebo,Luke DeMars,Christopher T Ertsgaard,Elias M Puchner
Spatial light modulation using cost efficient digital micromirror devices (DMD) is finding broad applications in fluorescence microscopy due to the reduction of phototoxicity and bleaching and the ability to manipulate proteins in optogenetic experiments. However, precise illumination by DMDs and their application to single-molecule localization microscopy (SMLM) remained a challenge because of non-linear
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Wide-field time-gated SPAD imager for phasor-based FLIM applications. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-02-05 Arin Ulku,Andrei Ardelean,Michel Antolovic,Shimon Weiss,Edoardo Charbon,Claudio Bruschini,Xavier Michalet
We describe the performance of a new wide area time-gated single-photon avalanche diode (SPAD) array for phasor-FLIM, exploring the effect of gate length, gate number and signal intensity on the measured lifetime accuracy and precision. We conclude that the detector functions essentially as an ideal shot noise limited sensor and is capable of video rate FLIM measurement. The phasor approach used in
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Fluorophore photostability and saturation in the hotspot of DNA origami nanoantennas. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-02-05 Lennart Grabenhorst,Kateryna Trofymchuk,Florian Steiner,Viktorija Glembockyte,Philip Tinnefeld
Fluorescent dyes used for single-molecule spectroscopy can undergo millions of excitation-emission cycles before photobleaching. Due to the upconcentration of light in a plasmonic hotspot, the conditions for fluorescent dyes are even more demanding in DNA origami nanoantennas. Here, we briefly review the current state of fluorophore stabilization for single-molecule imaging and reveal additional factors
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Ultrashort laser based two-photon phase-resolved fluorescence lifetime measurement method. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-01-30 Hafizah Halip,Yuto Yoshimura,Wataru Inami,Yoshimasa Kawata
This paper presents a two-photon phase-resolved fluorescence-lifetime measurement method based on the use of an ultrashort pulse laser. The proposed method also involves the use of a lock-in amplifier to control the phase difference between the reference and fluorescence signals, thereby facilitating the use of an alternative method for determining fluorescence lifetimes. Verification of the fluorescence
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Dynamic and static quenching of 2-aminopurine fluorescence by the natural DNA nucleotides in solution. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-01-30 Kyle A Paterson,Jochen Arlt,Anita C Jones
2-aminopurine (2AP) is a responsive fluorescent base analogue that is used widely as a probe of the local molecular environment in DNA. The ability of 2AP to report changes in local conformation and base-stacking interactions arises from the efficient quenching of its fluorescence by the natural DNA bases. However, the mechanism of this inter-base quenching remains imperfectly understood. Two previous
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Zinc oxide quantum dots embedded in hydrophobic silica particles for latent fingermarks visualization based on time-gated luminescence measurements. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-01-23 Izabela Olszowska,Adam Leśniewski,Anna Kelm,Izabela S Pieta,Antoni Siejca,Joanna Niedziółka-Jönsson
In this work we demonstrate a composite material based on silica particles. The particles have been doped with zinc oxide quantum dots which possess long living luminescence. The surface of the particles has been functionalized with phenyl groups using sol-gel process. The new material has been successfully applied for visualization of natural latent fingermarks on several surfaces, in particular,
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Optimization of FLIM imaging, fitting and analysis for auto-fluorescent NAD(P)H and FAD in cells and tissues. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2020-01-23 Ruofan Cao,Horst Wallrabe,Karsten Siller,Ammasi Periasamy
Increasingly, the auto-fluorescent coenzymes NAD(P)H and FAD are being tracked by multi-photon fluorescence lifetime microscopy (FLIM) and used as versatile markers for changes in mammalian metabolism. The cellular redox state of different cell model systems, organoids and tissue sections is investigated in a range of pathologies where the metabolism is disrupted or reprogrammed; the latter is particularly
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Exploring protein-protein interactions with large differences in protein expression levels using FLIM-FRET. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2019-12-23 Julien Godet,Yves Mély
Many molecular processes within a cell are carried out by molecular machines built from a large number of proteins organized by their protein-protein interactions (PPIs). Exploring PPIs in their cellular context is critical to better understand the proteins functions. Förster resonance energy transfer measured by fluorescence lifetime imaging (FLIM-FRET) enables to monitor PPIs and to map their spatial
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One-step hydrothermal synthesis of silver-doped carbon quantum dots for highly selective detection of uric acid. Methods Appl. Fluoresc. (IF 2.8) Pub Date : 2019-12-23 Shu Juan Zhuo,Jing Fang,Jing Wang,Chang Qing Zhu
In this paper, a simple and convenient fluorescence method for detection of uric acid (UA) based on Ag-doped carbon quantum dots (Ag-CQDs) is developed. The Ag-CQDs contain Ag species could bond with UA, which promoted the electron and/or energy transfer and produced high quenching extent. Thus, the fluorescence intensity of Ag-CQDs decreased in the presence of UA. Under the optimal condition, the