Read by QxMD icon Read

Methods and Applications in Fluorescence

P Stanley May, Mary Berry
The quantitative characterization of the spectroscopic properties of upconversion nanocrystals (UCNC) has lagged behind the progress made in other areas of UCNC research. This lag has slowed the overall advancement of UCNC research because, fundamentally, it has been difficult to compare the performance and characteristics of UCNC used across different studies. The purpose of this paper is to suggest how best to acquire, analyze and interpret upconversion luminescence data such that the results can be used by the research community for meaningful comparison...
January 29, 2019: Methods and Applications in Fluorescence
Blanca Del Rosal, Daniel Jaque Garcia
UCNPs have attracted a great deal of attention as near infrared-excited luminescent probes for biomedical applications. UCNPs can provide contrast for in vivo imaging, act as luminescent temperature reporters and excite different molecules to trigger therapeutic processes. While the unique features of UCNPs are well-suited for certain applications, their intrinsic limitations may prevent their general use in preclinical and clinical settings as luminescent probes. In this work, we analyze the role of UCNPs in research in small animal models...
January 29, 2019: Methods and Applications in Fluorescence
Marco Kraft, Christian Wuerth, Emilia Palo, Tero Soukka, Ute Resch-Genger
We present here a systematic analysis of the influence of Tm<sup>3+</sup> doping concentrations (<i>x<sub>Tm</sub></i>) on the excitation power (<i>P</i>)-dependent upconversion luminescence and -performance of hexagonal-phase NaYF<sub>4</sub>: 20 % Yb<sup>3+</sup>, <i>x<sub>Tm</sub></i> % Tm<sup>3+</sup> upconversion nanoparticles (UCNPs) for <i>x<sub>Tm</sub></i> of 0...
January 28, 2019: Methods and Applications in Fluorescence
Jacob Schwarz, Hannah J Leopold, Ryan Leighton, Robert C Miller, Cody P Aplin, Boersma J Arnold, Ahmed A Heikal, Erin D Sheets
Living cells are crowded with macromolecules and organelles, which affect a myriad of biochemical processes. As a result, there is a need for sensitive molecular sensors for quantitative, site-specific assessment of macromolecular crowding. Here, we investigated the excited-state dynamics of recently developed hetero-FRET sensors (mCerulean3-linker-mCitrine) in homogeneous and heterogeneous environments using time-resolved fluorescence measurements, which are compatible with fluorescence lifetime imaging microscopy (FLIM)...
January 28, 2019: Methods and Applications in Fluorescence
Hossein Soltaninejad, Amir Amiri Sadeghan, Saman Hosseinkhani, Mohammad Ali Asadollahi, Morteza Hosseini, Mohammad Reza Ganjali
Silver ions can influence DNA structure. The extent of this structural perturbation is different in methylated and non-methylated DNA. Here, we explored the interaction of eight convenient DNA interacting molecules with methylated and non-methylated short GC rich oligonucleotides in the presence and absence of silver ions. Acridine orange, DAPI, Doxorubicin, Ethidium bromide, Hoechst 33342, Methylene blue, PicoGreen, and Propidium iodide are tested for their ability to distinguish methylated and non-methylated DNA...
January 28, 2019: Methods and Applications in Fluorescence
Samaneh Rafiei, Mehdi Dadmehr, Morteza Hosseini, Hanie Ahmadzade Kermani, Mohammad Reza Ganjali
DNA methylation plays an important role in development process which contributes to genome stability and also regulates gene expression and gene silencing. Detection of genome regions with altered 5-methylcytosine distribution at a genome-wide scale is very important for early detection of gene silencing related diseases. In the present study as a continuation of studies on DNA methylation, the interactions between graphene quantum dots (GQDs) and unmethylated and methylated deoxyribonucleic acid (DNA) fragment were investigated...
January 17, 2019: Methods and Applications in Fluorescence
Jan Willem Borst, Petra van den Berg, Mark Hink
Appreciation of Professor Dr Visser.
January 17, 2019: Methods and Applications in Fluorescence
Erli Yang, Jiandong Yao, Lumin Wang, Yi Liu, Qi Xiao, Shan Huang
InP/ZnS quantum dot (QD)-based fluorescent probe for directly sensitive and selective detection of horseradish peroxidase (HRP) was reported herein. Fluorescence of InP/ZnS QDs was statically quenched by HRP, due to the ground state complex formation of InP/ZnS QDs with HRP. Such ground state complex formation between InP/ZnS QDs and HRP reduced both the α-helix content and the melting temperature of HRP. Several key factors including InP/ZnS QDs concentration, buffer pH value, ionic strength, reaction temperature, and reaction time those affected the analytical performance of InP/ZnS QDs in HRP determination were investigated thoroughly...
January 17, 2019: Methods and Applications in Fluorescence
Maysoon Saleh, Ihor Panas, Florian Frenzel, Christian Wuerth, Bastian Rühle, Yuri L Slominskii, Alexander Demchenko, Ute Resch-Genger
Photon upconversion nanomaterials have a wide range of applications, including biosensing and deep-tissue imaging. Their typically very weak and narrow absorption bands together with their size dependent luminescence efficiency can limit their application potential. This has been addressed by increasingly sophisticated core-shell particle architectures including the sensitization with organic dyes that strongly absorb in the near infrared (NIR). In this work, we present a simple water-dispersible micellar system that features energy transfer from the novel NIR excitable dye, 1859 SL with a high molar absorption coefficient and a moderate fluorescence quantum yield to oleate-capped NaYF<sub>4</sub>:20%Yb(III),2%Er(III) upconversion nanoparticles (UCNP) upon 808 nm excitation...
January 14, 2019: Methods and Applications in Fluorescence
David J S Birch, Yves Mely, Otto S Wolfbeis
Not needed.
January 7, 2019: Methods and Applications in Fluorescence
Gabrielle Mandl, Daniel Cooper, Thomas Hirsch, Jan Seuntjens, John A Capobianco
In this perspective, we aim to present an overview of some important physical and chemical aspects of lanthanide-doped upconverting nanoparticle research to be considered, from synthesis considerations to bioapplications. To this end, we have reviewed several practical considerations and prepared several straightforward recommendations toward improved cohesion in the field, based on observed trends over the last decade of research.&#13.
December 20, 2018: Methods and Applications in Fluorescence
Mohammadreza Khodabakhsh, Ugur Unal
Er<sup>3+</sup> doped BST nanoparticles with Aurivillius layered structure are synthesized through common solid-state method. Photoluminescence spectroscopy has shown that these oxides are capable of emitting light under UV (366nm) and IR (980nm) source. The effect of Er<sup>3+</sup> to Yb<sup>3+</sup> concentration ratio on upconversion emission are investigated and possible upconversion and energy transfer mechanisms are suggested based on the number of photons participating in UC process...
December 10, 2018: Methods and Applications in Fluorescence
Margaret Chern, Joshua C Kays, Shashi Bhuckory, Allison Dennis
Fluorescent sensors benefit from high signal-to-noise and multiple measurement modalities, allowing for a multitude of applications and flexibility of design. Semiconductor nanocrystal quantum dots (QDs) are excellent fluorophores for sensors because of their extraordinary optical properties. They have high thermal and photochemical stability compared to organic dyes or fluorescent proteins and are extremely bright due to their large molar cross-sections. In contrast to organic dyes, QD emission profiles are symmetric, with relatively low full width half maxima...
December 7, 2018: Methods and Applications in Fluorescence
Kristin Stefanie Grußmayer, Klaus Yserentant, Dirk-Peter Herten
The full understanding of cellular functions requires information about protein numbers for various biomolecular assemblies and their dynamics, which can be partly accessed by super-resolution fluorescence microscopy. Yet, many protein assemblies and cellular structures remain below the accessible resolution on the order of tens of nanometers thereby evading direct observation of processes, like self-association or oligomerization, that are crucial for many cellular functions. Over the recent years, several approaches have been developed addressing concentrations and copy numbers of biomolecules in cellular samples for specific applications...
November 22, 2018: Methods and Applications in Fluorescence
Sergiy V Avilov, Nataliia Aleksandrova
Conventional fragments of fluorescent proteins used in bimolecular fluorescence complementation technique (BiFC), form light-emitting species only when they are kept in close proximity by interacting proteins of interest. By contrast, certain fluorescent protein fragments complement spontaneously, namely those corresponding to the 1st to 10th beta-strands (GFP1-10) and the 11th beta-strand of superfolder GFP (GFP11). They were designed as folding reporters for high throughput expression and structure biology...
November 20, 2018: Methods and Applications in Fluorescence
Lianghui Luo, Wenbao Feng, Wanting Hu, Chuanyan Chen, Hang Gong, Changqun Cai
A novel designed fluorescence molecularly imprinted polymer (MIP) probe made from CdTe/CdS quantum dot (QD)-based silica nanoparticles (SiO2@MPS-CdTe/CdS) was successfully created via a sol-gel process. The target virus - hepatitis A virus (HAV) was selectively captured by imprinted polymer layer, resulting in the fluorescence quenching of the QDs within 20 min, which could be explained by the energy transfer mechanism. Under optimized conditions, the limit of detection for the SiO2@MPS-CdTe/CdS MIP was as low as 88 pmol∙L-1, and excellent linearity was obtained from 0...
November 14, 2018: Methods and Applications in Fluorescence
Sena Ghayem, Farnoush Faridbod
Cytochrome c (Cyt c), a heme protein, can be a potential biomarker for cell-apoptosis or even cancer diagnosis. In this work, a simple, rapid, sensitive and selective label-free assay for Cytochrome c (Cyt c) detection is introduced based on an interaction between nucleic acid aptamer biomolecules and surfaces of Carbon Dots (CDs). CDs are used as a fluorescent probes and Cyt c-aptamers as a sensing materials. Interactions of aptamers with CDs quench the fluorescent intensity of CDs. By addition of Cyt c biomolecule as an analyte to the solution and binding to the aptamers, CDs fluorescence turns on...
November 14, 2018: Methods and Applications in Fluorescence
B Couch, A Meyer, B Heller, S L Johnson
We present a spectroscopic method for measuring the fluorescence quantum efficiency [Formula: see text] of fluorophores that does not require calibration standards. Photothermal Deflection Spectroscopy (PDS) is combined with conventional absorbance spectroscopy, and [Formula: see text] is extracted from fits over the spectral range of interest. This technique obviates the need for multiple measurements-either on calibration standards or as a function of concentration-and yields results of [Formula: see text] in a single measurement consistent with previously reported values...
November 9, 2018: Methods and Applications in Fluorescence
Florian Baumgart, Andreas M Arnold, Benedikt K Rossboth, Mario Brameshuber, Gerhard J Schütz
Superresolution microscopy results have sparked the idea that many membrane proteins are not randomly distributed across the plasma membrane but are instead arranged in nanoclusters. Frequently, these new results seemed to confirm older data based on biochemical and electron microscopy experiments. Recently, however, it was recognized that multiple countings of the very same fluorescently labeled protein molecule can be easily confused with true protein clusters. Various strategies have been developed, which are intended to solve the problem of discriminating true protein clusters from imaging artifacts...
November 9, 2018: Methods and Applications in Fluorescence
Barbara Pem, Daniel González-Mancebo, Maria Moros, Manuel Ocaña, Ana Isabel Becerro, Ivan Pavičić, Atiđa Selmani, Michal Babič, Daniel Horák, Ivana Vinković Vrček
The safety assessment of nanoparticles (NPs) is crucial during their design and development for biomedicine. One of the prerequisite steps during this evaluation is in vitro testing that employs cell-based assays not always validated and well-adapted for NPs. Interferences with in vitro assays may arise due to the nano-related optical, oxidative, fluorescent, surface and catalytic properties of NPs. Thus, proper validation of each assay system has to be performed for each NP type. This study aimed to evaluate the applicability of the most common in vitro cytotoxicity assays for the safety assessment of up- and down-converting lanthanide-doped NPs...
November 6, 2018: Methods and Applications in Fluorescence
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"