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Applications of machine learning in time-domain fluorescence lifetime imaging: a review Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2024-02-08 Dorian Gouzou, Ali Taimori, Tarek Haloubi, Neil Finlayson, Qiang Wang, James R Hopgood, Marta Vallejo
Many medical imaging modalities have benefited from recent advances in Machine Learning (ML), specifically in deep learning, such as neural networks. Computers can be trained to investigate and enhance medical imaging methods without using valuable human resources. In recent years, Fluorescence Lifetime Imaging (FLIm) has received increasing attention from the ML community. FLIm goes beyond conventional
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Hidden in plain sight: hyperspectral documentation of complex biofluorescence produced by the green sea urchin (Strongylocentrotus droebachiensis) Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2024-02-07 Thomas Juhasz-Dora, Philip James, Tor Evensen, Stein-Kato Lindberg
Biofluorescence in echinoderms is largely unexplored, and even though the green sea urchin Strongylocentrotus droebachiensis is a well-studied species, the presence and/or function of fluorescence remains very poorly understood. Hyperspectral imaging was conducted on adult sea urchins (N = 380) while fluorospectrometric analysis was conducted on sea urchin coelomic fluid (N = 30). Fluorescence was
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3-aminophenylboronic acid modified carbon nitride quantum dots as fluorescent probe for selective detection of dopamine and cell imaging Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2024-01-03 Mingyu Gan, Rui Yao, Baoping Wang, Jiarong Li, Ning Wang, Martin M F Choi, Wei Bian
Dopamine (DA) is the most abundant catecholamine neurotransmitter in the brain and plays an extremely essential role in the physiological activities of the living organism. There is a critical need for accurately and efficiently detecting DA levels in organisms in order to reflect physiological states. Carbon nitride quantum dots (C3N4) were, in recent years, used enormously as electrochemical and
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Development and validation of synchronous spectrofluorimetric method for the simultaneous determination of duvelisib and moxifloxacin: greenness metric assessment and application to a pharmacokinetic study in rats Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-12-13 Weam M Othman, Nourah Z Al-Zoman, Ibrahim A Darwish, Aliyah Almomen, Nehal F Farid, Fatma F Abdallah, Samah S Saad
Duvelisib (DUV) is a potent anticancer drug whereas Moxifloxacin (MOX) is an antimicrobial drug with anti-proliferative potency against cancerous cells, which is empirically administered in cancer treatment. DUV and MOX combination is commonly prescribed to combat infections in patients while they are under chemotherapy treatment. This study describes, for the first time, the development of a simple
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Novel fluorescence approach for trace quantification of levonorgestrel in breast milk based on click reaction with benzonitrofurazan azide (NBD-AZ) Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-12-05 Heba A Aref, Ismail Salama, Shaimaa Mohamed Aboukhatwa, Mohamed A Helal, Safaa M Kishk, Mohamed Saleh Elgawish
Although the great importance of oral contraceptive agents in birth control, their existence in breast milk became a cause for concern, since infant exposure to these hormones is associated with many health problems. Consequentially, developing a sensitive bioanalytical method for monitoring their concentrations in breast milk is an urgent demand to examine the safety or the risk of these compounds
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Development of an analytical method for the determination of pesticides in tropical fruits by LC-QTOF-MS/MS after QuEChERS extraction sample cleanup and DLLME preconcentration Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-11-23 Sabriye Sel, Elif Öztürk Er, İkbal Koyuncu
In this study, QuEChERS extraction was combined with dispersive liquid–liquid microextraction (DLLME) to extract pesticides from tropical fruits for determination by a highly accurate and sensitive liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF-MS/MS) system. The QuEChERS method served as a matrix clean-up tool and the DLLME method preconcentrated the analytes for their
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Analysis of the fluorescent properties of vaginal fluid upon ageing Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-11-09 Judith de Vos, Rosa E Otto, Nihad Achetib, Anas Gasser, Maurice C G Aalders, Annemieke van Dam
Detection and identification of body fluids are crucial aspects of forensic investigations, aiding in crime scene reconstructions and providing important leads. Although many methods have been developed for these purposes, no method is currently in use in the forensic field that allows rapid, non-contact detection and identification of vaginal fluids directly at the crime scene. The development of
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Paper test strip for fluorescence detection of iron ion based on nitrogen, zinc and copper codoped carbon dots Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-11-03 Dou Yang, Shuhan Jiang, Shuai Zhang, Xiaoyu Fan, Xiaodong Shao, Shuhao Wang, Rui Li, Qiaoli Yue
In this study, a test strip for fluorometric analysis of iron ion (Fe3+) was constructed based on nitrogen, zinc and copper codoped carbon dots (NZC-CDs) as fluorescence probes. NZC-CDs were synthesized by hydrothermal method. The morphology, size, components, crystal state and optical properties of NZC-CDs were characterized by transmission electron microscope (TEM), Fourier-transform infrared (FT-IR)
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Effect of annealing on the room temperature luminescence of coumarin 106 in PVA films Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-11-02 Emma Alexander, Luca Ceresa, Danh Pham, Zygmunt Gryczynski, Ignacy Gryczynski
We studied the effect of annealing on the luminescence of Coumarin 106 (C106) in poly (vinyl alcohol) films (PVA films). The samples and reference polymer films were treated at temperatures between 100 °C and 150 °C (212 F and 302 F) for various times. After cooling and smoothing, the samples and references were measured at room temperature. We observed that the PVA polymer (reference films) changes
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Ratiometric fluorescence detection of the angiotensin-converting enzyme via single-excitation and double-emission biomass-derived carbon quantum dots Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-10-25 Zhihua Zhan, Huihui Mao, Mingyue Xue, Guocheng Han, Guohua Zhou, Ying Zhang
Efficient and rapid detection of angiotensin-converting enzyme (ACE) activity is important for preventing hypertension and the discovery of new angiotensin-converting enzyme inhibitors (ACEI). In this work, a single-excitation and double-emission biomass-derived carbon quantum dots (CQDs) was prepared and applied for ratiometric fluorescence detection of ACE. Fresh banyan leaves were extracted with
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A new twist on PIFE: photoisomerisation-related fluorescence enhancement Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-10-12 Evelyn Ploetz, Benjamin Ambrose, Anders Barth, Richard Börner, Felix Erichson, Achillefs N Kapanidis, Harold D Kim, Marcia Levitus, Timothy M Lohman, Abhishek Mazumder, David S Rueda, Fabio D Steffen, Thorben Cordes, Steven W Magennis, Eitan Lerner
PIFE was first used as an acronym for protein-induced fluorescence enhancement, which refers to the increase in fluorescence observed upon the interaction of a fluorophore, such as a cyanine, with a protein. This fluorescence enhancement is due to changes in the rate of cis/trans photoisomerisation. It is clear now that this mechanism is generally applicable to interactions with any biomolecule. In
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Comparison of MSD analysis from single particle tracking with MSD from images. Getting the best of both worlds Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-10-12 Constanza Kettmayer, Enrico Gratton, Laura C Estrada
Fluorescence microscopy can provide valuable information about cell interior dynamics. Particularly, mean squared displacement (MSD) analysis is widely used to characterize proteins and sub-cellular structures’ mobility providing the laws of molecular diffusion. The MSD curve is traditionally extracted from individual trajectories recorded by single-particle tracking-based techniques. More recently
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Emission color tuning and dual-mode luminescence thermometry design in Dy3+/Eu3+ co-doped SrMoO4 phosphors Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-10-12 Vaibhav Chauhan, Prashant Dixit, Prashant Kumar Pandey, Satyam Chaturvedi, Praveen C Pandey
The challenge of building a highly reliable contactless temperature probe with high sensitivity, good temperature-induced color discriminability, and economical synthesis has prompted the research community to work in the field of rare-earth-based luminescence thermometry. Moreover, the fast-growing market for optoelectronic devices has increased the demand for tunable color-emitting phosphors. In
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Carbon dots derived from citric acid and urea as fluorometric probe for determining melamine contamination in infant formula sample Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-10-12 Souliyanh Phimmasone, Pornthip Boonsri, Weena Siangproh, Nuanlaor Ratanawimarnwong, Piyada Jittangprasert, Thitirat Mantim, Nunticha Limchoowong, Kriangsak Songsrirote
Melamine has been intentionally added into food products to increase the protein count at less cost, especially in dairy products for infant resulting in serious adverse effects on health of consumers. Therefore, this study aimed to develop a method to quantify melamine in dairy products based on the change of fluorescent properties of carbon dots (CDs) as sensing probe. CDs with green-fluorescent
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Photo-physical characterization of high triplet yield brominated fluoresceins by transient state (TRAST) spectroscopy Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-10-03 Baris Demirbay, Glib Baryshnikov, Martin Haraldsson, Joachim Piguet, Hans Ågren, Jerker Widengren
Photo-induced dark transient states of fluorophores can pose a problem in fluorescence spectroscopy. However, their typically long lifetimes also make them highly environment sensitive, suggesting fluorophores with prominent dark-state formation yields to be used as microenvironmental sensors in bio-molecular spectroscopy and imaging. In this work, we analyzed the singlet–triplet transitions of fluorescein
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Green synthesis of fluorescent carbon dots from Robinia hispida L. leaves for selective detection of Hg (II) Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-09-26 Aysel Başoğlu
In this study, Robinia hispida L leaves (RH) was used as a precursor for the first time to synthesize fluorescent carbon dots (CDs) with stable blue fluorescence by a single-step hydrothermal synthesis method. Notably, the innovative approach eliminates the necessity for toxic chemicals or hazardous substances, marking a significant advancement in the field. The synthesized CDs demonstrate CDs demonstrates
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Measuring protein-membrane interaction through radial fluorescence correlation in 2 dimensions Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-09-18 N Philipp, E Gratton, L C Estrada
The cell membrane has a fundamental role in the cell life cycle but there’s still much to be learned about its heterogeneous structure, regulation, and protein interaction. Additionally, the protein-membrane interaction is often overlooked when studying specific protein dynamics. In this work, we present a new tool for a better understanding of protein dynamics and membrane function using live cells
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Multimodal fluorescence imaging and spectroscopic techniques for oral cancer screening: a real-time approach Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-09-13 Pramila Thapa, Veena Singh, Sunil Bhatt, Kiran Maurya, Virendra Kumar, Vivek Nayyar, Kiran Jot, Deepika Mishra, Anurag Shrivastava, Dalip Singh Mehta
The survival rate of oral squamous cell carcinoma (OSCC) patients is very poor, but it can be improved using highly sensitive, specific, and accurate techniques. Autofluorescence and fluorescence techniques are very sensitive and helpful in cancer screening; being directly linked with the molecular levels of human tissue, they can be used as a quantitative tool for cancer detection. Here, we report
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Quasi-equilibrium state based quantification of biological macromolecules in single-molecule localization microscopy Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-09-08 Xuecheng Chen, Yaqian Li, Xiaowei Li, Jielin Sun, Daniel M Czajkowsky, Zhifeng Shao
The stoichiometry of molecular components within supramolecular biological complexes is often an important property to understand their biological functioning, particularly within their native environment. While there are well established methods to determine stoichiometry in vitro, it is presently challenging to precisely quantify this property in vivo, especially with single molecule resolution that
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Rapid microwave synthesis of N and S dual-doped carbon quantum dots for natamycin determination based on fluorescence switch-off assay Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-08-25 Ali Abdel-Hakim, Fathalla Belal, Mohamed A Hammad, Mahmoud El-Maghrabey
Green, one-pot, quick, and easily synthesized nitrogen and sulfur co-doped carbon quantum dots (N,S-CDs) were obtained from cheap and readily available chemicals (sucrose, urea, and thiourea) using a microwave-assisted approach in about 4 min and utilized as a turn-off fluorescent sensor for estimation of natamycin (NAT). First, the effect of N and S doping on the microwave-synthesized CDs’ quantum
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DWH24: a new antibody for fluorescence-based cell death analysis Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-08-23 Anna Ryschich, Yan Dong, Michael Schäfer, Eduard Ryschich, Svetlana Karakhanova
Antibodies have gained considerable importance in laboratory and clinical settings. Currently, antibodies are extensively employed for the diagnosis and treatment of several human diseases. Herein, using targeted and cell immunisation approaches, we developed and characterised an antibody clone, DWH24. We found that DWH24 is an IgM κ type antibody that enables excellent visualisation and quantification
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Spectrofluorometric determination of cinacalcet hydrochloride: greenness assessment and application to biological fluids and in-vitro dissolution testing Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-07-26 Mona H Abo Zaid, Nahed El-Enany, Aziza E Mostafa, Ghada M Hadad, Fathalla Belal
A facile, simple, green and sensitive spectrofluorometric method was developed for determination of the calcimimetic drug cinacalcet hydrochloride. It is used for the treatment of hyperparathyroidism. The drug showed high native fluorescence intensity at 320 nm after excitation at 280 nm. The method was linear over the range of 5.0–400.0 ng ml−1 with excellent correlation (R2 = 0.9999). Limit of detection
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Probing the potential toxicity of trimetazidine by characterizing its interaction with human serum albumin Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-07-19 Aya Barseem, Fathalla Belal, Mokhtar Mabrouk, Sherin Hammad, Hytham Ahmed
The small molecular drugs pharmacodynamics and pharmacokinetics could be affected by human serum albumin (HSA) transport, so we studied the interaction between HSA and the widely used anti-ischemic agent, trimetazidine (TMZ), using different approaches. As shown by synchronous fluorescence spectroscopy, the interaction affects the microenvironment confirmation around tyrosine residues. The site-competitive
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Visualization of the composition of the urinary fluorescent metabolome. Why is it important to consider initial urine concentration? Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-07-19 Katarína Dubayová, Anna Birková, Martin Lešo, Jaroslava Žilková, Anton Karabinoš, Mária Mareková, Marek Stupák
Urine is a highly complex fluorescent system, the fluorescence of which can be affected by many factors, including the often-ignored initial urine concentration in comprehensive fluorescent urine analysis. In this study, a total urine fluorescent metabolome profile (uTFMP) was created as a three-dimensional fluorescence profile of serial synchronous spectra of urine diluted by geometric progression
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Excited-state properties of 6-methoxyflavone in the presence of halide ions in aqueous media Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-07-07 Nisha Fatma, Sanjay Pant, Nupur Pandey, Mohan Singh Mehata
The present work investigated the influence of different halides on the excited state dynamics of 6-methoxyflavone (6MF) in an aqueous solution with steady-state and time-resolved techniques. On successive addition of I− and Br− ions, the fluorescence of 6MF quenched significantly, whereas the respective ions do not change the maximum fluorescence band. Fluorescence of 6MF was quenched 66% by I− ions
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Real-time correction of chromatic aberration in optical fluorescence microscopy Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-07-03 Ana Cayuela López, Pablo Conesa, Ana María Oña Blanco, José Antonio Gómez-Pedrero, Carlos Oscar S Sorzano
Multi-color fluorescence imaging is a powerful tool for studying the spatial relationships and interactions among sub-cellular structures in biological specimens. However, if improperly corrected, geometrical distortions caused by mechanical drift, refractive index mismatch, or chromatic aberration can lead to lower image resolution. In this paper, we present an extension of the image processing framework
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Study of the senescence of rice leaves through stationary and time-resolved photoluminescence Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-06-12 G Fonthal, L Tirado-Mejía, L A Giraldo-Pinto
This work describes the relationship between the complex of photosystem I and photosystem II in the senescence process of rice leaves observed through changes in the optical response. We studied three varieties of rice plants at different aging times using time-resolved photoluminescence to measure the time decay of the emission, and stationary photoluminescence, to measure the emission wavelength
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Two-photon lifetime-based photoconversion of EGFP for 3D-photostimulation in FLIM Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-06-12 Dita Strachotová, Aleš Holoubek, Barbora Brodská, Petr Heřman
Enhanced green fluorescence protein (EGFP) is a fluorescent tag commonly used in cellular and biomedical applications. Surprisingly, some interesting photochemical properties of EGFP have remained unexplored. Here we report on two-photon-induced photoconversion of EGFP, which can be permanently converted by intense IR irradiation to a form with a short fluorescence lifetime and spectrally conserved
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Influence of polyvinylpyrrolidone (PVP) in the synthesis of luminescent NaYF4:Yb,Er upconversion nanoparticles Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-05-30 Ross Birch, Jochen Bruckbauer, Marta Gajewska, Grzegorz Cios, Robert Pal, Lewis E MacKenzie
Polyvinylpyrrolidone (PVP) can be used to produce upconversion nanoparticles (UCNPs) in an advantageous manner, i.e. at modest temperatures in open-to-air conditions with simple hotplate and flask apparatus. However, the influence of PVP parameters on the formation of UCNPs has not been previously investigated. In this exploratory study, we establish that PVP molecular weight and relative amount of
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A comparative study of conventional FRET and light harvesting properties of Rh-110/Rh-6G and Rh-19/Rh-B organic dye pairs impregnated in sol-gel glasses Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-05-05 Kapil Dev Mahato, Uday Kumar
Two different pairs of laser dyes, Rhodamine-110 (Rh-110)/Rhodamine-6G (Rh-6G) and Rhodamine-19 (Rh-19)/Rhodamine-B (Rh-B) (the first dye in each pair as a donor and the second as an acceptor) were impregnated in silica samples prepared by the sol-gel method and spectroscopically studied using absorption and steady-state fluorescence techniques. The critical transfer distance (R0), actual distance
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Dual emission and its λ-ratiometric detection in analytical fluorimetry. Pt. I. Basic mechanisms of generating the reporter signal Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-04-21 Alexander P Demchenko
The wavelength-ratiometric techniques gain increasing popularity in fluorescence probing and sensing for providing inner reference to output signal and removing instrumental artefacts, in this way increasing the sensitivity and reliability of assays. Recent developments demonstrate that such approach can allow achieving much more, with the application of broad range of novel molecular and nanoscale
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Surface plasmon enhanced fluorescence: self-consistent classical treatment in the quasi-static limit Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-04-20 Dentcho A Genov
The problem of enhanced molecular emission in close proximity to dielectric and metallic interfaces is of great importance for many physical and biological applications. Here we present an exact treatment of the problem from the view point of classical electromagnetism. Self-consistent analytical theory of the surface enhanced fluorescence (SEF) is developed for configurations consisting of an emitter
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Dual emission and its λ-ratiometric detection in analytical fluorimetry Pt. II. Exploration in sensing and imaging Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-04-18 Alexander P Demchenko
The wavelength-ratiometric techniques demonstrate strong advantages in fluorescence sensing and imaging over techniques employing variations of intensity at single wavelength. We present different possibilities for realization of these advantages in different simplified, miniaturized and multiplexing devices. They include the smartphone-based detection systems and strips, in which the color changes
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Corrigendum: Pulse-shaped broadband multiphoton excitation for single-molecule fluorescence detection in the far field (2023Methods Appl. Fluoresc.11017001). Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-04-14 David Nobis,Henry G Sansom,Steven W Magennis
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Fluorescence quenching determination of tetracyclines based on the synergistic oxidation effect between Fe3O4 nanoparticles and tetracyclines Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-04-13 Shiqi Guo, Yilin Chai, Yongjun Wu, Hongchao Guo, Fei Yu, Li-e Liu, Leiliang He, Songcheng Yu, Yongmei Tian, Jia Wang, Ruiying Yang, Ningge Jian, Yilin Wang
In recent years, tetracyclines (TCs) is a hot research topic. Herein, we report an interesting discovery using the complexation of oxytetracycline and metal ions. In this study, according to the properties of Fe3O4 nanoparticles (Fe3O4 NPs) as a nanoenzyme, it can be used to catalyze the oxidation of KI by H2O2 to produce I3−, while at the same time I3− binds to rhodamine 6G (Rh6G) to form a conjoined
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Room Temperature Phosphorescence of 5,6-Benzoquinoline Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-04-03 Jose Chavez, Luca Ceresa, Emma Kitchner, Danh Pham, Zygmunt Gryczynski, Ignacy Gryczynski
Phosphorescence emission of 5,6-Benzoquinoline embedded in poly (vinyl alcohol) film has been studied at room temperature. A strong green long-lived emission was observed in films doped with 5,6-Benzoquinoline while illuminated on a UV plate. A broad phosphorescence emission spectrum is centered at about 500 nm. The phosphorescence excitation spectrum follows the absorption spectrum of 5,6-Benzoquinoline
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Fluorescent carbon dots tailored iron oxide nano hybrid system for in vivo optical imaging of liver fibrosis Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-03-21 Shaiju S Nazeer, Ariya Saraswathy, Nirmala Nimi, Elangovan Sarathkumar, A N Resmi, Sachin J Shenoy, Ramapurath S Jayasree
Hybrid nanoparticles are innovative invention of last decade designed to overcome limitations of single-component nanoparticles by introducing multiple functionalities through combining two or more different nanoparticles. In this study, we are reporting development of magneto-fluorescent hybrid nanoparticles by combining iron oxide and carbon nanoparticles to enable in vivo fluorescence imaging which
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Compact and robust deep learning architecture for fluorescence lifetime imaging and FPGA implementation Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-03-20 Zhenya Zang, Dong Xiao, Quan Wang, Ziao Jiao, Yu Chen, David Day Uei Li
This paper reports a bespoke adder-based deep learning network for time-domain fluorescence lifetime imaging (FLIM). By leveraging the l1 -norm extraction method, we propose a 1D Fluorescence Lifetime AdderNet (FLAN) without multiplication-based convolutions to reduce the computational complexity. Further, we compressed fluorescence decays in temporal dimension using a log-scale merging technique to
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Multi-stimuli-responsive and dynamic color tunable security ink for multilevel anticounterfeiting Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-03-15 Charu Dubey, Anjana Yadav, Diksha Baloni, Sachin Singh, Anjani Kumar Singh, Sunil Kumar Singh, Akhilesh Kumar Singh
Luminescent security features have been used for anticounterfeiting for a long time. However, constant effort is required to strengthen these security features to be ahead of counterfeiters. Here, we developed a multi-stimuli-responsive luminescent security ink containing Tb(ASA)3Phen, K2SiF6:Mn4+, and NaYF4:Yb3+/Er3+ luminescent materials in PVC gold medium. Tb(ASA)3Phen complex shows a broad excitation
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Enhanced emission intensity in (Li+/Ca2+/Bi3+) ions co-doped NaLa(MoO4)2: Dy3+phosphors and their Judd-Ofelt analysis for WLEDs applications Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-03-01 Sonali1, C Shivakumara
In the present study, we have synthesized a series of Dy3+ ion doped NaLa(MoO4)2phosphors by the conventional solid-state method at 750 °C for 4h. All the compounds were crystallized in the tetragonal scheelite type structure with space group (I41/a, No.88). The morphology and functional group were confirmed by the field emission scanning electron microscopy (FE-SEM) and Fourier transform infrared(FTIR)spectroscopy
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Tutorial: multiphoton microscopy to advance neuroscience research Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-02-22 Iván Coto Hernández, Jenny Yau, Lars Rishøj, Nanke Cui, Steven Minderler, Nate Jowett
Multiphoton microscopy (MPM) employs ultrafast infrared lasers for high-resolution deep three-dimensional imaging of live biological samples. The goal of this tutorial is to provide a practical guide to MPM imaging for novice microscopy developers and life-science users. Principles of MPM, microscope setup, and labeling strategies are discussed. Use of MPM to achieve unprecedented imaging depth of
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Effect of buffers and pH in antenna sensitized Eu(III) luminescence Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-02-07 Lea Gundorff Nielsen, Thomas Just Sørensen
The photophysics of a europium(III) complex of 1,4,7,10-tetraazacycododecane-1,4,7-triacetic acid-10-(2-methylene)-1-azathioxanthone was investigated in three buffer systems and at three pH values. The buffers—phosphate buffered saline (PBS), 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES), and universal buffer (UB)—had no effect on the europium luminescence, but a lower overall emission
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Structural and optical variation of pseudoisocyanine aggregates nucleated on DNA substrates Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-01-31 Matthew Chiriboga, Christopher M Green, Divita Mathur, David A Hastman, Joseph S Melinger, Remi Veneziano, Igor L Medintz, Sebastián A Díaz
Coherently coupled pseudoisocyanine (PIC) dye aggregates have demonstrated the ability to delocalize electronic excitations and ultimately migrate excitons with much higher efficiency than similar designs where excitations are isolated to individual chromophores. Here, we report initial evidence of a new type of PIC aggregate, formed through heterogeneous nucleation on DNA oligonucleotides, displaying
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Pulse-shaped broadband multiphoton excitation for single-molecule fluorescence detection in the far field Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2023-01-19 David Nobis, Henry G Sansom, Steven W Magennis
Multiphoton excitation of fluorescence has many potential advantages over resonant (one-photon) excitation, but the method has not found widespread use for ultrasensitive applications. We recently described an approach to the multiphoton excitation of single molecules that uses a pulse shaper to compress and tailor pulses from an ultrafast broadband laser in order to optimise the brightness and signal-to-background
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MINFLUX imaging of a bacterial molecular machine at nanometer resolution Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2022-12-13 Alexander Carsten, Maren Rudolph, Tobias Weihs, Roman Schmidt, Isabelle Jansen, Christian A Wurm, Andreas Diepold, Antonio Virgilio Failla, Manuel Wolters, Martin Aepfelbacher
The resolution achievable with the established super-resolution fluorescence nanoscopy methods, such as STORM or STED, is in general not sufficient to resolve protein complexes or even individual proteins. Recently, minimal photon flux (MINFLUX) nanoscopy has been introduced that combines the strengths of STED and STORM nanoscopy and can achieve a localization precision of less than 5 nm. We established
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Keratin intrinsic fluorescence as a mechanism for non-invasive monitoring of its glycation Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2022-12-01 Rhona Muir, Shareen Forbes, David J S Birch, Vladislav Vyshemirsky, Olaf J Rolinski
We have studied the evolution of keratin intrinsic fluorescence as an indicator of its glycation. Steady-state and time-resolved fluorescence of free keratin and keratin-glucose samples were detected in PBS solutions in vitro. The changes in the fluorescence response demonstrate that the effect of glucose is manifest in the accelerated formation of fluorescent cross-links with an emission peak at 460
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Preparation, AIE and ESIPT behaviour, controllable solid-state fluorescence and application of Co2+ probe based on α-cyanostilbene Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2022-11-25 Meihui Chen, Wenheng Huang, Yangping Li, Yongchun Chen, Dan Ji, Mingguang Zhu
A simple α-cyanostilbene-functioned salicylaldehyde-based Schiff-base probe, which exhibited outstanding ‘aggregation-induced emission and excited state intramolecular proton transfer (AIE + ESIPT)’ emission in solution, aggregation and solid states, was synthesized in high yield of 87%. Its solid-states with different morphologies emitted different fluorescence after crystallization in EtOH/H2O (1/2
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Comparative study of upconversion and photoacoustic measurements of Er3+/Yb3+ doped La2O3 phosphor under 980 nm Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2022-11-16 Minarul I Sarkar, Neeraj Kumar Mishra, Kaushal Kumar
The Er3+/Yb3+doped La2O3 phosphor samples were synthesized by the combustion method and then photoluminescence and photoacoustic spectroscopic studies were done. Prepared samples were annealed at 800 °C, 1000 °C and 1300 °C and all samples were found in pure hexagonal phase as confirmed by XRD analysis. From FE-SEM images it is found that particle size increases with increase in annealing temperature
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A novel conjugated polymer fluorescence probe for the detection of copper ions in aqueous media Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2022-11-16 Lindan Gong, Lixiao Zhang, Rui Shen, Lin Zhang, Hengyuan Wang, Lu-an Fan
A novel ionic conjugated polymer fluorescent probe (IP) containing fluorenyls and imines was synthesized through a simple condensation method for the rapid detection of Cu2+. The probe exhibited a selective quenching response toward Cu2+ over other common metal ions in phosphate-buffered saline (PBS) at a pH of 7. Moreover, the fluorescence intensity of IP was linearly proportional to the concentration
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Phasor-based multi-harmonic unmixing for in-vivo hyperspectral imaging Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2022-11-09 Alexander Vallmitjana, Paola Lepanto, Florencia Irigoin, Leonel Malacrida
Hyperspectral imaging (HSI) is a paramount technique in biomedical science, however, unmixing and quantification of each spectral component is a challenging task. Traditional unmixing relies on algorithms that need spectroscopic parameters from the fluorescent species in the sample. The phasor-based multi-harmonic unmixing method requires only the empirical measurement of the pure species to compute
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Photophysical, optical and lasing analysis of fluorinated β-keto carboxylate europium(III) complexes Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2022-11-03 Savita Khatri, Pratibha Ahlawat, S P Khatkar, V B Taxak, Rajesh Kumar
Six luminescent, bright red Eu(III) complexes with a β-keto-carboxylic acid as prime ligand and N-donor aromatic systems as auxillary ligand were synthesised via ecologically efficient grinding method. The distinctive red peak (5D0 → 7F2) of Eu(III) ion is exhibited in emission spectra of all complexes. The luminescent properties of complexes were analysed through decay time, color coordinates, luminescence
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One-pot ultrasonicated synthesized lead-less hybrid perovskite nanocrystals: structural, morphological and optical analysis Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2022-10-18 Rajan Kumar Singh, Sourabh Gouraha, Anupriya Singh, Neha Jain, Jai Singh
In contemporary years, hybrid lead halide perovskites nanocrystals (HPNCs) have emerged as core materials for low-cost solution-processable photovoltaic, light-emitting devices as well as in other optoelectronic fields, such as high-efficiency perovskite fluorescent quantum dots (quantum dot, QD). Although the high efficiency makes them an attractive active material, reducing the Pb-toxicity and enhancing
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Non-invasive assessment of intestinal permeability in healthy volunteers using transcutaneous fluorescence spectroscopy Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2022-10-10 Jonathan Gan, Elena Monfort Sánchez, James Avery, Omar Barbouti, Jonathan Hoare, Hutan Ashrafian, Ara Darzi, Alex J Thompson
The permeability of the intestinal barrier is altered in a multitude of gastrointestinal conditions such as Crohn’s and coeliac disease. However, the clinical utility of gut permeability is currently limited due to a lack of reliable diagnostic tests. To address this issue, we report a novel technique for rapid, non-invasive measurement of gut permeability based on transcutaneous (‘through-the-skin’)
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Fluorescence measurements: importance of G-factor correction, magic angle, and observation wavelengths Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2022-09-26 Emma Kitchner, Michael Seung, Jose Chavez, Luca Ceresa, Joseph Kimball, Ignacy Gryczynski, Zygmunt Gryczynski
Excitation and emission (observation) conditions heavily impact fluorescence measurements. Both observed spectra and intensity decays (fluorescence lifetimes), when incorrectly measured, may lead to incorrect data interpretations. In this report, we discuss the role of observation conditions in steady-state and time-resolved (lifetime) fluorescence measurements. We demonstrate the importance of the
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Label-free monitoring of proteins in optofluidic hollow-core photonic crystal fibres Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2022-09-20 Jan R Heck, Ermanno Miele, Ralf Mouthaan, Michael H Frosz, Tuomas P J Knowles, Tijmen G Euser
The fluorescent detection of proteins without labels or stains, which affect their behaviour and require additional genetic or chemical preparation, has broad applications to biological research. However, standard approaches require large sample volumes or analyse only a small fraction of the sample. Here we use optofluidic hollow-core photonic crystal fibres to detect and quantify sub-microlitre volumes
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Deciphering modes of long-range energy transfer in perovskite crystals using confocal excitation and wide-field fluorescence spectral imaging Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2022-09-16 Tejmani Behera, Nithin Pathoor, Rajat Mukherjee, Arindam Chowdhury
Excitation energy migration beyond mesoscale is of contemporary interest for both solar photovoltaic and light-emissive devices, especially in context of organometal halide perovskites (OMHPs) which have been shown to have very long (charge carrier) diffusion lengths. While understanding the energy propagation pathways in OMHPs is crucial for further advancement of material design and improvement of
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Correlation analyses reveal differential diffusion behavior of eisosomal proteins between mother and daughter cells Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2022-09-14 Francisco G Correa Tedesco, Pablo S Aguilar, Laura C Estrada
Eisosomes are nanoscale plasma membrane domains shaped as furrow-like invaginations. In Saccharomyces cerevisiae these relatively immobile and uniform structures are mainly composed of two cytoplasmic proteins Pil1 and Lsp1. The present work uses fluctuation of fluorescence signals and analytical methods to determine Pil1 and Lsp1 dynamics at different subcellular locations. Using scanning techniques
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i-scope: a compact automated fluorescence microscope for cell counting applications in low resource settings Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2022-09-13 Arti Tyagi, Neha Khaware, Bramha Tripathi, Tushar Jeet, Prabhu Balasubramanian, Ravikrishnan Elangovan
Fluorescence microscopy has widespread applications across biological sciences. It has been routinely used for cell counting, which provides a preliminary diagnostic test for many infectious diseases. Conventional fluorescence microscopes are bulky, expensive, time-intensive and laborious. They often require trained operators to acquire and analyze data. We report a compact automated digital fluorescence
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A high-sensitivity rapid acquisition spectrometer for lanthanide(III) luminescence Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2022-09-09 Patrick R Nawrocki, Villads R M Nielsen, Thomas Just Sørensen
Detecting luminescence beyond 750–800 nm becomes problematic as most conventional detectors are less sensitive in this range, and as simple corrections stops being accurate. Lanthanide luminescence occurs in narrow bands across the spectrum from 350–2000 nm. The most emissive lanthanide(III) ions have bands from 450 nm to 850 nm, some with additional bands in the NIR. Investigating NIR bands are hard
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The innards of the cell: studies of water dipolar relaxation using the ACDAN fluorescent probe Methods Appl. Fluoresc. (IF 3.2) Pub Date : 2022-09-07 Santiago Otaiza-González, Manuel Cabadas, German Robert, Roberto P Stock, Leonel Malacrida, Ramiro Lascano, Luis A Bagatolli
This article reviews the use of the 6-acetyl-2-(dimethylamino)naphthalene (ACDAN) fluorophore to study dipolar relaxation in cells, tissues, and biomimetic systems. As the most hydrophilic member of the 6-acyl-2-(dimethylamino)naphthalene series, ACDAN markedly partitions to aqueous environments. In contrast to 6-lauroyl-2-(dimethylamino)naphthalene (LAURDAN), the hydrophobic and best-known member