scholarly journals J-Aggregates of Cyanine Dyes in Aqueous Solution of Polymers: A Quantitative Study

2004 ◽  
Vol 3 (3) ◽  
Author(s):  
Wesley Tillmann ◽  
Hussein Samha
Keyword(s):  
Aqueous Solution ◽  
Quantitative Study ◽  
Aggregation Number ◽  
Cyanine Dyes ◽  
Cyanine Dye ◽  
Isosbestic Point ◽  
Maximum Capacity ◽  
Vis Spectroscopy ◽  
J Aggregates

The effect of polyvinylsulfate (PVS) on the spectroscopy of the cyanine dye, 1,1’-diethyl-2,2’-cyanine iodide (PIC), has been investigated using UV-vis spectroscopy. J-aggregates of the PIC dye were formed upon addition of PVS to the monomers of the dye in solution. The appearance of only one isosbestic point in the UV-vis spectra suggests that the dye monomers are quantitatively converted to J-aggregates and equilibrium was reached. Using Benisi-Hildebrand kinetics, aggregation number of 4 was calculated for the dye. In addition, a 1:2 mole ratio of PIC/PVS was calculated at the maximum capacity of the polymer.

scholarly journals Aggregation of Cyanine Dye in Bilayer Vesicles of Phospholipids

2005 ◽  
Vol 4 (3) ◽  
Author(s):  
Casey McCullough ◽  
Matthew Heywood ◽  
Hussein Samha
Keyword(s):  
Aqueous Solution ◽  
Equilibrium Constant ◽  
Room Temperature ◽  
Aggregation Number ◽  
Cyanine Dye ◽  
Molar Ratio ◽  
Isosbestic Point ◽  
Dye Molecules ◽  
Vis Spectroscopy ◽  
J Aggregates

The effect of phospholipid, 1,2-Dipalmitoyl-sn-glycero-3-Phosphocholine (DPPC) on the spectroscopy of the cyanine dye, 1-ethyl-1’-octadecyl-2,2’-cyanine iodide (PIC-18), has been investigated using UV-Vis spectroscopy. Vesicles of DPPC containing PIC-18 in the molar ratio of 1:3 (dye/phospholipids) were prepared in aqueous solution. J-aggregates of PIC-18 were detected in the bilayer wall of the vesicles. When an aqueous solution of mixed PIC-18/DPPC vesicles is treated with excess DPPC vesicles that are prepared separately, the dye molecules in the mixed vesicles underwent a rapid (aggregate)n' n(monomer) equilibrium as the appearance of only one isosbestic point in the absorbance of the dye indicates. The equilibrium constant was calculated at room temperature (Keq = 6.7x10-2). An aggregation number of 4 was calculated for the dye in the bilayer vesicles.

scholarly journals Investigation of the Effect of Concentration on Molecular Aggregation of Cyanine Dyes in Aqueous Solution

2011 ◽  
Vol 9 (4) ◽  
Author(s):  
John Kunzler ◽  
Leen Samha ◽  
Renwu Zhang ◽  
Hussein Samha
Keyword(s):  
Aqueous Solution ◽  
Emission Spectroscopy ◽  
Visible Region ◽  
Cyanine Dyes ◽  
Cyanine Dye ◽  
Molecular Aggregation ◽  
Monomeric Form ◽  
Strong Emission ◽  
Absorption And Emission ◽  
Absorption And Emission Spectroscopy

The aggregation of the cyanine dye, 3,3’-disulfobutyl-5,5’-dichloro thiacarbocyanine triethylamine, (NK-3796) in aqueous solution was investigated using absorption and emission spectroscopy. The equilibrium, n(monomer) ⇆ n(dimer) ⇆ (H-aggregate)n , was observed over a series of dye concentrations ranging from 10-4 mM to 0.1mM. At concentrations <10-3 mM, the dye exists in solution mostly in the monomeric form. However, dimers become more significant when the concentration of the dye exceeds 10-2 mM. Unlike the substituted dye in the 9th position, the NK-3796 dye tends to form H-aggregates at higher concentration (>10-1 mM). Monomers and dimers exhibit strong emission in the visible region. Also notable, is that the emission from the H-aggregates was very weak due to self quenching.

scholarly journals Principles for Self-Assembly of Cyanine Dyes into 2-Dimensional Excitonic Aggregates Across the Visible and Near-Infrared

2020 ◽  
Author(s):  
Arundhati Deshmukh ◽  
Austin Bailey ◽  
Leandra Forte ◽  
Xingyu Shen ◽  
Niklas Geue ◽  
...  
Keyword(s):  
Self Assembly ◽  
Near Infrared ◽  
Dynamic Equilibrium ◽  
Structural Information ◽  
Photophysical Properties ◽  
Cyanine Dyes ◽  
Cyanine Dye ◽  
Extensive Literature ◽  
Solvent Ratio ◽  
J Aggregates

<div>Cyanine dyes show a remarkable tendency to form non-covalent supramolecular aggregates with diverse morphologies (dimers, sheets, tubes and bundles). Specific molecular arrangements within these H- or J-aggregates dictate the extraordinary photophysical properties, including long-range exciton delocalization, extreme redshifts, and excitonic superradiance. Despite extensive literature on cyanine dye aggregates, design principles that drive the solution self-assembly to a preferred H- or J-aggregated state are unknown. We present a general approach to tune the thermodynamics of self-assembly, selectively stabilizing H- or J-aggregates and thereby achieving supramolecular control over aggregate photophysics. A simple interplay of solvent to non-solvent ratio, ionic strength or dye concentration yields a broad range of conditions that predictably and preferentially stabilize the monomer, H- or J-aggregate species that can be easily monitored using absorption spectroscopy. Diffusion ordered spectroscopy, cryo-electron microscopy and atomic force microscopy together reveal a dynamic equilibrium between monomers, H-aggregated dimers, and extended J-aggregated 2-dimensional monolayers. This structural information informs a three-component equilibrium model that describes the observed concentration dependence of spectral signatures, showing excellent fit with experimental data and yields the Gibb’s free energies of self-assembly for dimerization and 2D aggregate assembly. We further demonstrate the universality of this approach among several sheet forming cyanine dyes including the benzothiazole and benzimidazole families with absorptions spanning visible, near and shortwave infrared wavelengths.</div>

scholarly journals Molecular Distribution Behavior of Cyanine Dyes in Aqueous Solution

2009 ◽  
Vol 7 (4) ◽  
Author(s):  
David Baumann ◽  
Bryan Clark ◽  
Jared Garlick ◽  
Hussein Samha
Keyword(s):  
Aqueous Solution ◽  
Narrow Band ◽  
Ammonium Phosphate ◽  
Emission Spectra ◽  
Cyanine Dye ◽  
Concentrated Solutions ◽  
Molecular Distribution ◽  
J Aggregates ◽  
Absorption And Emission Spectroscopy ◽  
Distribution Behavior

The molecular distribution of the cyanine dye (5-chloro-2-[3-[5-chloro-3-(4-sulfobutyl)-2(3H)-benzothiazolylidine]-1-propenyl]-3-(4-sulfobutyl)-benzothiazolium hydroxide triethylamine salt, NK-3796) in aqueous solution was investigated using absorption and emission spectroscopy. Dimers of the dye are formed in concentrated solutions, while monomers dominate more diluted solutions. J aggregates are formed in solutions containing electrolytes such as sodium chloride, calcium chloride, and di-hydrogen ammonium phosphate. The dye readily forms J aggregates upon mixing with electrolyte. The J aggregates formation was followed spectroscopically by the appearance of a red-shifted narrow band centered at 653 nm in the absorption spectra. A similar shift is also observed in the emission spectra. The absorbance bandwidth is dependent on the charge of the cation of the electrolyte. This suggests different ground-state conformations for the J aggregates in solution.

scholarly journals Self Assembly of Cyanine Dye on Clay Nanoparticles

2005 ◽  
Vol 3 (4) ◽  
Author(s):  
Andrew Dixon ◽  
Clint Duncan ◽  
Hussein Samha
Keyword(s):  
Aqueous Solutions ◽  
Self Assembly ◽  
Montmorillonite Clay ◽  
Cyanine Dye ◽  
Clay Particles ◽  
Clay Nanoparticles ◽  
Charged Surfaces ◽  
Successive Addition ◽  
Vis Spectroscopy ◽  
J Aggregates

The effect of Ca-montmorillonite (clay) on the aggregation behavior of the cyanine dye, 1,1’-diethyl-2,2’-cyanine iodide (PIC), in aqueous solutions has been investigated using UV-vis spectroscopy. The absorbance of the monomeric dye in aqueous solutions is compared with the absorbance of the aggregates formed after adding the clay. The appearance of a sharp “red-shifted” band centered at 574 nm, after the addition of clay to the aqueous solutions of the dye, indicates the formation J-aggregates on the charged surfaces of the clay particles. The spontaneous and quantitative transformation of monomers into J-aggregates was controlled by the concentration of the clay in the solution. Successive addition of clay to the dye solution causes an increase in the absorbance intensity of the J-band and consequently, a decrease in the absorbance intensity of the monomer. These changes occur linearly which suggests that the dye monomers are quantitatively being converted to J-aggregates.

UV-vis Spectroscopy and Cyclic Voltammetry Investigations of Tubular J-Aggregates of Amphiphilic Cyanine Dyes

2019 ◽  
Vol 16 (28) ◽  
pp. 77-84 ◽  
Author(s):  
Jennifer L L. Lyon ◽  
Doerthe Eisele ◽  
Stefan Kirstein ◽  
Jürgen P Rabe ◽  
David A Vanden Bout ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Cyanine Dyes ◽  
Vis Spectroscopy ◽  
J Aggregates

scholarly journals Principles for Self-Assembly of Cyanine Dyes into 2-Dimensional Excitonic Aggregates Across the Visible and Near-Infrared

2020 ◽  
Author(s):  
Arundhati Deshmukh ◽  
Austin Bailey ◽  
Leandra Forte ◽  
Xingyu Shen ◽  
Niklas Geue ◽  
...  
Keyword(s):  
Self Assembly ◽  
Near Infrared ◽  
Dynamic Equilibrium ◽  
Structural Information ◽  
Photophysical Properties ◽  
Cyanine Dyes ◽  
Cyanine Dye ◽  
Extensive Literature ◽  
Solvent Ratio ◽  
J Aggregates

<div>Cyanine dyes show a remarkable tendency to form non-covalent supramolecular aggregates with diverse morphologies (dimers, sheets, tubes and bundles). Specific molecular arrangements within these H- or J-aggregates dictate the extraordinary photophysical properties, including long-range exciton delocalization, extreme redshifts, and excitonic superradiance. Despite extensive literature on cyanine dye aggregates, design principles that drive the solution self-assembly to a preferred H- or J-aggregated state are unknown. We present a general approach to tune the thermodynamics of self-assembly, selectively stabilizing H- or J-aggregates and thereby achieving supramolecular control over aggregate photophysics. A simple interplay of solvent to non-solvent ratio, ionic strength or dye concentration yields a broad range of conditions that predictably and preferentially stabilize the monomer, H- or J-aggregate species that can be easily monitored using absorption spectroscopy. Diffusion ordered spectroscopy, cryo-electron microscopy and atomic force microscopy together reveal a dynamic equilibrium between monomers, H-aggregated dimers, and extended J-aggregated 2-dimensional monolayers. This structural information informs a three-component equilibrium model that describes the observed concentration dependence of spectral signatures, showing excellent fit with experimental data and yields the Gibb’s free energies of self-assembly for dimerization and 2D aggregate assembly. We further demonstrate the universality of this approach among several sheet forming cyanine dyes including the benzothiazole and benzimidazole families with absorptions spanning visible, near and shortwave infrared wavelengths.</div>

Quantitative study on the interaction of Ag+ and Pd2+ with CNT-graft-PCA (polycitric acid) in aqueous solution

2013 ◽  
Vol 180 ◽  
pp. 39-44 ◽  
Author(s):  
N. Sarlak ◽  
M. Adeli ◽  
M. Karimi ◽  
M. Bordbare ◽  
M.A. Farahmandnejad
Keyword(s):  
Aqueous Solution ◽  
Quantitative Study

scholarly journals ᶫ-Leucine Loading and Release in MIL-100 Nanoparticles

2020 ◽  
Vol 21 (24) ◽  
pp. 9758
Author(s):  
Ivan E. Gorban ◽  
Mikhail A. Soldatov ◽  
Vera V. Butova ◽  
Pavel V. Medvedev ◽  
Olga A. Burachevskaya ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Hydrothermal Synthesis ◽  
Cell Model ◽  
Metal Organic Framework ◽  
Acetic Acid Solution ◽  
Sorption Isotherms ◽  
Microwave Assisted Synthesis ◽  
High Porosity ◽  
Cytotoxicity Studies ◽  
Vis Spectroscopy

Synthesis of the MIL-100 metal-organic framework particles was carried out by hydrothermal (HT) and microwave (MW)-assisted methods. Transmission electron microscopy showed formation of microparticles in the course of hydrothermal synthesis and nanoparticles for microwave-assisted synthesis. Powder X-ray diffraction confirmed formation of larger crystallites for hydrothermal synthesis. Particle aggregation in aqueous solution was observed by dynamic light scattering. However, the stability of both samples could be improved in acetic acid solution. Nitrogen sorption isotherms showed high porosity of the particles. ᶫ-leucine molecule was used as a model molecule for loading in the porous micro- and nanoparticles. Loading was estimated by FTIR spectroscopy and thermogravimetric analysis. UV-VIS spectroscopy quantified ᶫ-leucine release from the particles in aqueous solution. Cytotoxicity studies using the HeLa cell model showed that the original particles were somewhat toxic, but ᶫ-leucine loading ameliorated the toxic effects, likely due to signaling properties of the amino acid.

scholarly journals Exploiting cyanine dye J-aggregates/monomer equilibrium in hydrophobic protein pockets for efficient multi-step phototherapy: An innovative concept for smart nanotheranostics

Nanoscale ◽  
2021 ◽  
Author(s):  
Matias Luis Picchio ◽  
Julian Bergueiro Álvarez ◽  
Stefanie Wedepohl ◽  
Roque J Minari ◽  
Cecilia Ines Alvarez Igarzabal ◽  
...  
Keyword(s):  
Indocyanine Green ◽  
Contrast Agent ◽  
Photothermal Therapy ◽  
Near Infrared ◽  
Cyanine Dye ◽  
Hydrophobic Protein ◽  
Nir Dyes ◽  
Protein Pockets ◽  
J Aggregates ◽  
Innovative Concept

After several decades of development in the field of near-infrared (NIR) dyes for photothermal therapy (PTT), indocyanine green (ICG) still remains the only FDA-approved NIR contrast agent. However, upon NIR...

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