scholarly journals Visualizing monolayers with a water-soluble fluorophore to quantify adsorption, desorption, and the double layer

2015 ◽  
Vol 112 (8) ◽  
pp. E826-E835 ◽  
Author(s):  
Ian C. Shieh ◽  
Joseph A. Zasadzinski
Keyword(s):  
Double Layer ◽  
Fluorescent Dyes ◽  
Selective Adsorption ◽  
Dye Adsorption ◽  
Immiscible Liquid ◽  
Water Soluble ◽  
Fluorescence Signal ◽  
Anionic Phospholipid ◽  
Gas Phases ◽  
Disordered Phase

Contrast in confocal microscopy of phase-separated monolayers at the air–water interface can be generated by the selective adsorption of water-soluble fluorescent dyes to disordered monolayer phases. Optical sectioning minimizes the fluorescence signal from the subphase, whereas convolution of the measured point spread function with a simple box model of the interface provides quantitative assessment of the excess dye concentration associated with the monolayer. Coexisting liquid-expanded, liquid-condensed, and gas phases could be visualized due to differential dye adsorption in the liquid-expanded and gas phases. Dye preferentially adsorbed to the liquid-disordered phase during immiscible liquid–liquid phase coexistence, and the contrast persisted through the critical point as shown by characteristic circle-to-stripe shape transitions. The measured dye concentration in the disordered phase depended on the phase composition and surface pressure, and the dye was expelled from the film at the end of coexistence. The excess concentration of a cationic dye within the double layer adjacent to an anionic phospholipid monolayer was quantified as a function of subphase ionic strength, and the changes in measured excess agreed with those predicted by the mean-field Gouy–Chapman equations. This provided a rapid and noninvasive optical method of measuring the fractional dissociation of lipid headgroups and the monolayer surface potential.

scholarly journals The formation and constitution of crystals of lead salts containing water-soluble colloid

1935 ◽  
Vol 235 (749) ◽  
pp. 125-164 ◽  
Keyword(s):  
Selective Adsorption ◽  
Water Soluble ◽  
Lead Salts ◽  
The Subject ◽  
As If ◽  
Saturated Solutions

The influence of small amounts of dissolved foreign substances on the growth of crystals from saturated solutions has been the subject of much investigation. Usually the added substances have been electrolytes. Dyestuffs have not been neglected, but with some few exceptions comparatively little attention has been given to the effect of non-ionized water-soluble electrolytes such as gelatine or dextrine. As a rule, the presence of the foreign substances is found to cause the crystals to assume a different habit. Whenever this occurs the absorption must have occurred on certain crystal-faces in preference to others, but, although the added material is active by virtue of its close attachment to such faces, it is rarely found to be incorporated into the solid to any great extent. The growing crystals appear to reject the impurity—thrusting it outwards as the growth advances. The action of water-soluble colloids on the halides and certain other salts of lead is exceptional in several ways. Although when such colloids are present in small concentrations one can generally observe a modification of habit, at higher concentrations there may be little selective adsorption, and the result may be a rounded crystal on which no plane faces at all can be distinguished, as if the forces by which atoms are attracted to the structure had been equalized in every direction.

scholarly journals Sulfobetaine Cryogels for Preferential Adsorption of Methyl Orange from Mixed Dye Solutions

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 208
Author(s):  
Ramona B. J. Ihlenburg ◽  
Anne-Catherine Lehnen ◽  
Joachim Koetz ◽  
Andreas Taubert
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Methyl Orange ◽  
Dye Removal ◽  
Selective Adsorption ◽  
Water Soluble ◽  
Organic Substances ◽  
Preferential Adsorption ◽  
Dimethyl Ammonium ◽  
Dye Solutions

New cryogels for selective dye removal from aqueous solution were prepared by free radical polymerization from the highly water-soluble crosslinker N,N,N’,N’-tetramethyl-N,N’-bis(2-ethylmethacrylate)-propyl-1,3-diammonium dibromide and the sulfobetaine monomer 2-(N-3-sulfopropyl-N,N-dimethyl ammonium)ethyl methacrylate. The resulting white and opaque cryogels have micrometer sized pores with a smaller substructure. They adsorb methyl orange (MO) but not methylene blue (MB) from aqueous solution. Mixtures of MO and MB can be separated through selective adsorption of the MO to the cryogels while the MB remains in solution. The resulting cryogels are thus candidates for the removal of hazardous organic substances, as exemplified by MO and MB, from water. Clearly, it is possible that the cryogels are also potentially interesting for removal of other compounds such as pharmaceuticals or pesticides, but this must be investigated further.

scholarly journals Fibrillar pharmacology of functionalized nanocellulose

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sam Wong ◽  
Simone Alidori ◽  
Barbara P. Mello ◽  
Bryan Aristega Almeida ◽  
David Ulmert ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Fluorescent Dyes ◽  
Pharmacokinetic Profile ◽  
Water Soluble ◽  
Size Exclusion ◽  
Hydroxyl Groups ◽  
Target Tissue ◽  
Exclusion Chromatography ◽  
Specific Accumulation

AbstractCellulose nanocrystals (CNC) are linear organic nanomaterials derived from an abundant naturally occurring biopolymer resource. Strategic modification of the primary and secondary hydroxyl groups on the CNC introduces amine and iodine group substitution, respectively. The amine groups (0.285 mmol of amine per gram of functionalized CNC (fCNC)) are further reacted with radiometal loaded-chelates or fluorescent dyes as tracers to evaluate the pharmacokinetic profile of the fCNC in vivo. In this way, these nanoscale macromolecules can be covalently functionalized and yield water-soluble and biocompatible fibrillar nanoplatforms for gene, drug and radionuclide delivery in vivo. Transmission electron microscopy of fCNC reveals a length of 162.4 ± 16.3 nm, diameter of 11.2 ± 1.52 nm and aspect ratio of 16.4 ± 1.94 per particle (mean ± SEM) and is confirmed using atomic force microscopy. Size exclusion chromatography of macromolecular fCNC describes a fibrillar molecular behavior as evidenced by retention times typical of late eluting small molecules and functionalized carbon nanotubes. In vivo, greater than 50% of intravenously injected radiolabeled fCNC is excreted in the urine within 1 h post administration and is consistent with the pharmacological profile observed for other rigid, high aspect ratio macromolecules. Tissue distribution of fCNC shows accumulation in kidneys, liver, and spleen (14.6 ± 6.0; 6.1 ± 2.6; and 7.7 ± 1.4% of the injected activity per gram of tissue, respectively) at 72 h post-administration. Confocal fluorescence microscopy reveals cell-specific accumulation in these target tissue sinks. In summary, our findings suggest that functionalized nanocellulose can be used as a potential drug delivery platform for the kidneys.

Degradation of Oil- and Water-Soluble Fluorescent Dyes

2010 ◽  
Author(s):  
Lav R Khot ◽  
Masoud Salyani ◽  
Roy D Sweeb
Keyword(s):  
Fluorescent Dyes ◽  
Water Soluble

Fluorescence signaling molecularly imprinted polymers for antibiotics prepared via site-directed post-imprinting introduction of plural fluorescent reporters within the recognition cavity

2016 ◽  
Vol 4 (44) ◽  
pp. 7138-7145 ◽  
Author(s):  
Hirobumi Sunayama ◽  
Takeo Ohta ◽  
Atsushi Kuwahara ◽  
Toshifumi Takeuchi
Keyword(s):  
Molecular Imprinting ◽  
Molecularly Imprinted Polymers ◽  
Fluorescent Dyes ◽  
Specific Binding ◽  
Fluorescence Signal ◽  
Molecularly Imprinted ◽  
Imprinted Polymers ◽  
Fluorescent Reporters ◽  
Binding Event ◽  
Fluorescence Signaling

An antibiotic-imprinted cavity with two different fluorescent dyes was prepared by molecular imprinting and subsequent post-imprinting modifications (PIMs), for the readout of a specific binding event as a fluorescence signal.

Water-Soluble Phospholo[3,2-b ]phosphole-P ,P ′-Dioxide-Based Fluorescent Dyes with High Photostability

2018 ◽  
Vol 13 (12) ◽  
pp. 1616-1624 ◽  
Author(s):  
Chenguang Wang ◽  
Aiko Fukazawa ◽  
Yoshiyuki Tanabe ◽  
Naoto Inai ◽  
Daisuke Yokogawa ◽  
...  
Keyword(s):  
Fluorescent Dyes ◽  
Water Soluble

A Label-Free Fluorescent AND Logic Gate Aptasensor for Carbohydrate Antigen 15-3 Detection Based on Graphene Oxide

2021 ◽  
Vol 24 ◽  
Author(s):  
Wenxiao Hu ◽  
Yafei Dong ◽  
Luhui Wang ◽  
Yue Wang ◽  
Mengyao Qian ◽  
...  
Keyword(s):  
Fluorescent Dyes ◽  
Logic Gate ◽  
High Sensitivity ◽  
Carbohydrate Antigen ◽  
Fluorescence Signal ◽  
Label Free ◽  
Molecular Logic ◽  
Long Stem ◽  
Middle Ring ◽  
Fluorescent Aptasensor

Background: Molecular logic gate always used fluorescent dyes to realize fluorescence signal. The labeling of the fluorophore is relatively expensive, low yield and singly labeled impuritiesaffects the affinity between the target and the aptamer. Label-free fluorescent aptamer biosensor strategy has attracted widespread interest due to lower cost and simple. Objective: Herein, we have designed a AND logic gate fluorescent aptasensor for detecting carbohydrate antigen 15-3(CA15-3) based on label-free fluorescence signal output. Materials and Methods: A hairpin DNA probe consists of CA15-3 aptamer and partly anti-CA15-3 aptamer sequences as a long stem and G-rich sequences of the middle ring as a quadruplex-forming oligomer. G-rich sequences can fold into a quadruplex by K+, and then G-quadruplex interacts specifically with N-methylmesoporphyrin IX(NMM), leading to a dramatic increase in fluorescence of NMM. With CA15-3 and NMM as the two inputs, the fluorescence intensity of the NMM is the output signal. Lacking of CA15-3 or NMM, there is no significant fluorescence enhancing, and the output of the signal is “0”. The fluorescence signal was dramatically increasing and the output of the signal is “1” only when CA15-3 protein and NMM were added at the same time. Results: This biosensor strategy possessed selectivity, high sensitivity for detecting CA15-3 protein from 10 to 500 U mL-1 and the detection limit was 10 U mL-1, and also showed good reproducibility in spiked human serum. Conclusion: In summary, the proposed AND logic gate fluorescent aptasensor could specifically detect CA15-3.

Human spectrin Src homology 3 domain binding protein 1 regulates macropinocytosis in NIH 3T3 cells

2000 ◽  
Vol 113 (21) ◽  
pp. 3805-3814 ◽  
Author(s):  
J. Xu ◽  
D. Ziemnicka ◽  
G.S. Merz ◽  
L. Kotula
Keyword(s):  
Fluorescent Dyes ◽  
Fluorescent Protein ◽  
Cultured Cells ◽  
Binding Protein ◽  
Sh3 Domain ◽  
Water Soluble ◽  
Protein Markers ◽  
3T3 Cells ◽  
Nih 3T3 ◽  
Nih 3T3 Cells

Macropinocytosis is an endocytic process that occurs through non-clathrin coated vesicles larger than 0.2 microm in diameter. Although macropinocytic vesicles are readily visualized in cultured cells by the introduction of fluorescent, water-soluble dyes into the culture medium, protein markers associated with this type of vesicles have not yet been well defined. Here, we report that human spectrin SH3 domain binding protein 1, or Hssh3bp1, associates with macropinosomes in NIH 3T3 fibroblasts. Hssh3bp1 macropinosomes are heterogeneous in morphology and size, do not endocytose transferrin and are resistant to brefeldin A treatment. Cytochalasin D, and wortmannin block endocytosis of fluorescent dyes into the Hssh3bp1 macropinosomes and dramatically affect their morphology. Overexpression of Hssh3bp1-green fluorescent protein abolished fusion of vesicles resulting in a decreased endocytosis of fluorescence dyes, thus suggesting a potential regulatory role of Hssh3bp1 in macropinocytosis. In the macropinosomes of NIH 3T3 cells, Hssh3bp1 associates with a 200-kDa protein that crossreacts with a monoclonal antibody to the erythroid alpha-spectrin SH3 domain. Thus macropinosomes in cells may contain a spectrin-like protein.

Confocal Laser Scanning Microscopy of Hamster Cerebellum using FM4-64 as Intracellular Staining

1998 ◽  
Vol 4 (S2) ◽  
pp. 1126-1127
Author(s):  
O. Castejón ◽  
P. Sims
Keyword(s):  
Confocal Laser Scanning Microscopy ◽  
Laser Scanning ◽  
Granular Layer ◽  
Fluorescent Dyes ◽  
Laser Scanning Microscopy ◽  
Climbing Fibers ◽  
Confocal Laser Scanning ◽  
Scanning Microscopy ◽  
Confocal Laser ◽  
Fluorescence Signal

Confocal laser scanning microscopy is an excellent method to study nerve cell morphology and the three-dimensional distribution and interrelationship of dentrites and axons in the central nervous system. The cerebellum has been taking as a model of a gray center.The FM4-64, a member of the family of fluorescent dyes, has been applied to the cerebellar cortex to evaluate its properties as an intracellular stain and intracortical tracer. Slabs of hamster cerebellum,5 mm thick, were incubated in 10,30 and 100 μm solutions of FM4-64 in sodium phosphate buffer and observed in a slow scan confocal laser scanning microscope. Mossy and climbing fibers were traced in the cerebellar white and gray substances .They exhibited high fluorescence signal at the level of myelin sheath.Mossy fibers were identified in the granular layer by their typical rosette formation and dichotomous bifurcation pattern. Climbing fibers bundles were observed crossing the granular layer and giving collateral branches around Golgi cell bodies.

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