- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Heteroatom-substituted rhodamine dyes: Structure and spectroscopic properties
摘要： Rhodamine is one class of most popular dyes used in fluorescence imaging due to the outstanding photoproperties including high brightness and photostability. In recent years, replacement the xanthene oxygen with other elements, especially silicon, has attracted great attentions in the development of new rhodamine derivatives. This review summarized the structures and photophysical properties of heteroatom-substituted rhodamines. We hope this review can help to understand the structure-property relationships of rhodamine dyes and then elucidate the way to create derivatives with improved photoproperties.
关键词： Heteroatom,Optical properties,Si-rhodamine,Rhodamine,Fluorescent dyes
更新于2025-09-23 15:23:52
-
Near-infrared fluorescence laparoscopy of the ureter with three preclinical dyes in a pig model
摘要： Background Ureteric injury is reported to occur in 1–7.6% of colorectal surgeries. To reduce the incidence of ureteral injury, it is essential to identify the ureters. The use of near-infrared fluorescence (NIRF) imaging with intravenously administered dyes might be of added value for ureteral visualization during laparoscopy. The aim of this study is to assess the performance of three preclinical dyes; IRDye? 800BK, IRDye? 800NOS and IRDye? 800CW, for near-infrared fluorescence laparoscopy of the ureter in pigs. Methods In three female Dutch landrace pigs, the new dyes were evaluated. In each pig, 1 dye was tested using a 6-mg intravenous dose in a concentration of 1?mg/ml. Imaging was performed in fluorescence mode and white light mode with a laparoscopic imaging system. In order to further evaluate the dyes, an ex?vivo imaging experiment was performed, in which 8 decreasing concentrations per dye, diluted in PBS, were evaluated in a transparent test tube with NIRF mode at a distance of 1, 5 and 10?cm from the laparoscope. Results All three dyes were effective in allowing the identification of the ureter with NIRF imaging. The ureter became fluorescent after 35, 45 and 10?min, respectively, for IRDye? 800BK, IRDye? 800NOS and IRDye? 800CW with a maximum target-to-background ratio (TBR) of 2.14, 0.66 and 1.44, respectively. In the ex?vivo imaging experiment, all three dyes produced a strong fluorescence signal at all concentrations and all distances evaluated. Conclusions Intravenous administration of the preclinical dyes IRDye? 800CW, IRDye? 800 BK and IRDye? 800NOS facilitated successful identification of the anatomical course of the ureter in living pig models. The highest measured TBR occurred with the use of IRDye? 800BK. Ex?vivo, a correlation was observed between the fluorescence intensities of the signal with the concentration of the dye and with the distance to the object.
关键词： laparoscopic colorectal surgery,Near-infrared fluorescence imaging,Ureter,Fluorescent dyes
更新于2025-09-23 15:21:21
-
Dual-Activatable Cell Tracker for Controlled and Prolonged Single-Cell Labeling
摘要： Cell trackers are fluorescent chemical tools that facilitate imaging and tracking cells within live organisms. Despite their versatility, these dyes lack specificity, tend to leak outside of the cell and stain neighboring cells. Here, we report a dual activatable cell tracker for increased spatial and temporal staining control, especially for single-cell tracking. This probe overcomes the typical problems of current cell trackers: off-target staining, high background signal, and leakage from the intracellular medium. Staining with this dye is not cytotoxic and it can be used in sensitive primary cells. Moreover, this dye is resistant to harsh fixation and permeabilization conditions and allows for multi-wavelength studies with confocal microscopy and fluorescence-activated cell sorting. Using this cell tracker, we performed in vivo homing experiments in mice with primary splenocytes and tracked a single cell in a heterogenous, multicellular culture environment for over 20 h. These experiments, in addition to comparative proliferation studies with other cell trackers, demonstrated that the signal from this dye is retained in cells for over 72 h after photoactivation. We envision that this type of probes will facilitate the analysis of single-cell behavior and migration in cell culture and in vivo experiments.
关键词： fluorescent dyes,photoactivation,single-cell tracking,cell trackers,intracellular labeling
更新于2025-09-23 15:19:57
-
Surface passivation of zero-mode waveguide nanostructures: benchmarking protocols and fluorescent labels
摘要： Zero mode waveguide (ZMW) nanoapertures efficiently confine the light down to the nanometer scale and overcome the diffraction limit in single molecule fluorescence analysis. However, unwanted adhesion of the fluorescent molecules on the ZMW surface can severely hamper the experiments. therefore a proper surface passivation is required for ZMWs, but information is currently lacking on both the nature of the adhesion phenomenon and the optimization of the different passivation protocols. Here we monitor the influence of the fluorescent dye (Alexa Fluor 546 and 647, Atto 550 and 647N) on the non-specific adhesion of double stranded DNA molecule. We show that the nonspecific adhesion of DNA double strands onto the ZMW surface is directly mediated by the organic fluorescent dye being used, as Atto 550 and Atto 647N show a pronounced tendency to adhere to the ZMW while the Alexa Fluor 546 and 647 are remarkably free of this effect. Despite the small size of the fluorescent label, the surface charge and hydrophobicity of the dye appear to play a key role in promoting the DNA affinity for the ZMW surface. Next, different surface passivation methods (bovine serum albumin BSA, polyethylene glycol PEG, polyvinylphosphonic acid PVPA) are quantitatively benchmarked by fluorescence correlation spectroscopy to determine the most efficient approaches to prevent the adsorption of Atto 647N labeled DNA. Protocols using PVPA and PEG-silane of 1000 Da molar mass are found to drastically avoid the non-specific adsorption into ZMWs. Optimizing both the choice of the fluorescent dye and the surface passivation protocol are highly significant to expand the use of ZMWs for single molecule fluorescence applications.
关键词： fluorescent dyes,Zero mode waveguide,single molecule fluorescence,DNA adhesion,surface passivation
更新于2025-09-19 17:13:59
-
Fluorescent 2-(pyridin-2-yl)vinyl pyridine dyes and their thermo-controlled release
摘要： The generation of unique thermosensitive fluorescent dyes via heteroaromatic Heck cross-coupling and N-pyridin-2-yl nucleophilic substitution was described. To demonstrate thermosensitive properties, the precursor was converted into carbonate or phosphate and heating at various temperatures and times of heating. Significant changes in fluorescence intensity and emission wavelengths, between carbonates and the cyclic product, were observed and proved that dyes may serve as removable fluorescent labels with large Stokes shifts (>80 nm). Application of thermosensitive fluorescent dyes in oligonucleotide labelling has been demonstrated.
关键词： Heck cross-coupling,large Stokes shifts,N-pyridin-2-yl nucleophilic substitution,thermosensitive fluorescent dyes,oligonucleotide labelling
更新于2025-09-16 10:30:52
-
Highly cooperative fluorescence switching of self-assembled squaraine dye at tunable threshold temperatures using thermosensitive nanovesicles for optical sensing and imaging
摘要： Thermosensitive fluorescent dyes can convert thermal signals into optical signals as a molecular nanoprobe. These nanoprobes are playing an increasingly important part in optical temperature sensing and imaging at the nano- and microscale. However, the ability of a fluorescent dye itself has sensitivity and accuracy limitations. Here we present a molecular strategy based on self-assembly to overcome such limitations. We found that thermosensitive nanovesicles composed of lipids and a unique fluorescent dye exhibit fluorescence switching characteristics at a threshold temperature. The switch is rapid and reversible and has a high signal to background ratio (>60), and is also highly sensitive to temperature (10–22%/°C) around the threshold value. Furthermore, the threshold temperature at which fluorescence switching is induced, can be tuned according to the phase transition temperature of the lipid bilayer membrane forming the nanovesicles. Spectroscopic analysis indicated that the fluorescence switching is induced by the aggregation-caused quenching and disaggregation-induced emission of the fluorescent dye in a cooperative response to the thermotropic phase transition of the membrane. This mechanism presents a useful approach for chemical and material design to develop fluorescent nanomaterials with superior fluorescence sensitivity to thermal signals for optical temperature sensing and imaging at the nano- and microscales.
关键词： fluorescence switching,optical sensing,nanovesicles,thermosensitive fluorescent dyes,imaging
更新于2025-09-11 14:15:04
-
Self-healing dyes for super-resolution fluorescence microscopy
摘要： In recent years, optical microscopy techniques have emerged that allow optical imaging at unprecedented resolution beyond the diffraction limit. These techniques exploit photostabilizing buffers to enable photoswitching and/or the enhancement of fluorophore brightness and stability. A major drawback with the use of photostabilizing buffers, however, is that they cannot be used in live cell imaging. In this paper, we tested the performance of self-healing organic fluorophores, which undergo intramolecular photostabilization, in super-resolution microscopy examining both targeted (stimulated emission depletion (STED) microscopy) and stochastic readout (stochastic optical reconstruction microscopy (STORM)). The overall goal of the study was to identify dyes and conditions that lead to improved spatial and temporal resolution of both techniques without the need for mixtures of photostabilizing agents in the imaging buffer. As a result of previously shown superior performance, we identified an ATTO647N-photostabilizer conjugate as a potential candidate for STED microscopy. We have here characterized the photostability and resulting performance of this nitrophenylalanine (NPA) conjugate of ATTO647N on oligonucleotides in STED microscopy. We found that the superior photophysical performance resulted in optimal STED imaging and demonstrated that single-molecule fluorescent transients of individual fluorophores can be obtained with both the excitation- and STED-laser. In similar experiments, we also tested a nitrophenylacetic acid conjugate of STAR635P, another frequently used dye in STED microscopy, and present a characterization of its photophysical properties. Finally, we performed an analysis of the photoswitching kinetics of self-healing Cy5 dyes (containing trolox, cyclooctatetraene and NPA-based stabilizers) in the presence of Tris(2-carboxyethyl) phosphine and cysteamine, which are typically used in STORM microscopy. In line with previous work, we found that intramolecular photostabilization strongly influences photoswitching kinetics and requires careful attention when designing STORM-experiments. In summary, this contribution explores the possibilities and limitations of self-healing dyes in super-resolution microscopy of differing modalities.
关键词： STORM,super-resolution microscopy,fluorescent dyes,STED,fluorescence microscopy
更新于2025-09-09 09:28:46
-
Performance of Fluorescent Cell-Labeling Dyes under Simulated Europa Mission Radiation Doses
摘要： We investigated the performance of several commonly used fluorescent dyes after exposure to a simulated Europa mission total ionizing radiation dose of 300 krad (3 kGy) applied using a 60Co source. Dyes irradiated in aqueous solution or as lyophilized powders were evaluated for absorbance and emission spectra, quantum yield, and where appropriate, ability to label cells or nucleic acids. Although some dyes showed significant increase or decrease in quantum yield with the dose, their spectra and cell-labeling properties remained essentially unchanged after irradiation in powder form. Irradiation in aqueous solution led to significantly greater changes, including a large blue shift in the DNA intercalator propidium iodide. These results suggest that many fluorescent probes are appropriate for use in astrobiological missions to Europa, but that SYTO9 and propidium iodide should be used with caution or not mixed with each other, as is commonly done in "Live/Dead" labeling applications.
关键词： Europa mission,fluorescent dyes,ionizing radiation,cell-labeling,astrobiology
更新于2025-09-04 15:30:14