Fluorescence Dynamics of Coumarin C522 on Reduced-Charge Montmorillonite in Aqueous Dispersion

Žitňan, Michal; Szöcs, V.; Janek, M.; Bugár, I.; Bdzoch, Juraj; Pálszegi, T.; Link, Guido; Velič, Dušan

doi:10.1021/la9006795

Cited by 10 publications

(6 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A similar spectroscopic behavior, i.e., a much more pronounced red shift of the absorption/excitation band compared to the spectral position of the emission band was also reported e.g., for coumarin 522 in a clay host. 14 Moreover, for the interpretation of these data, also the considerable decrease in the fluorescence quantum yield of Nile Red with increasing solvent polarity has to be considered (Figure 3), indicating an almost complete loss of dye emission in highly polar environments. Hence, we ascribe the broad absorption band at ca.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

“…2,8 The majority of these studies focused on cationic dyes like methylene blue, 9 acridine orange, 10,11 crystal violet, 12 and rhodamine 6G, 13 whereas there exist only comparatively few reports on clay adsorption of neutral dyes. Examples include coumarin dyes, 14,15 porphyrins, 16 and pyrenes 17 as well as other aromatic hydrocarbons, for which the detailed nature of the host−guest interactions has not been clarified yet. Otherwise, fluorescent nanoclays can be obtained via covalent attachment of reactive dyes at the edges of the nanoclay sheets after surface modification using silanization chemistries.…”

Section: ■ Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Nile-Red–Nanoclay Hybrids: Red Emissive Optical Probes for Use in Aqueous Dispersion

et al. 2013

View full text Add to dashboard Cite

Water-dispersible and (bio)functionalizable nanoclays have a considerable potential as inexpensive carriers for organic molecules like drugs and fluorophores. Aiming at simple design strategies for red-emissive optical probes for the life sciences from commercial precursors with minimum synthetic effort, we systematically studied the dye loading behavior and stability of differently functionalized laponites. Here, we present a comprehensive study of the absorption and emission properties of the red emissive hydrophobic and neutral dye Nile Red, a well-known polarity probe, which is almost insoluble and nonemissive in water. Adsorption of this probe onto disk-shaped nanoclays was studied in aqueous dispersion as function of dye concentration, in the absence and presence of the cationic surfactant cetyltrimethylammonium bromide (CTAB) assisting dye loading, and as a function of pH. This laponite loading strategy yields strongly fluorescent nanoclay suspensions with a fluorescence quantum yield of 0.34 at low dye loading concentration. The dye concentration-, CTAB-, and pH-dependent absorption, fluorescence emission, and fluorescence excitation spectra of the Nile-Red-nanoclay suspensions suggest the formation of several Nile Red species including emissive Nile Red monomers facing a polar environment, nonemissive H-type dimers, and protonated Nile Red molecules that are also nonfluorescent. Formation of all nonemissive Nile Red species could be suppressed by modification of the laponite with CTAB. This underlines the great potential of properly modified and functionalized laponite nanodisks as platform for optical probes with drug delivery capacities, for example, for tumor and therapy imaging. Moreover, comparison of the Nile Red dimer absorption spectra with absorption spectra of previously studied Nile Red aggregates in dendrimer systems and micelles and other literature systems reveals a considerable dependence of the dimer absorption band on microenvironment polarity which has not yet been reported so far for H-type dye aggregates.

show abstract

Section: ■ Experimental Sectionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

Nile-Red–Nanoclay Hybrids: Red Emissive Optical Probes for Use in Aqueous Dispersion

et al. 2013

View full text Add to dashboard Cite

show abstract

“…This indicated that a non-ionic dye such as Coumarine was not adsorbed at detectable concentrations on the charged and hydrated surface of montmorillonite. The affinity of Coumarine dye for the montmorillonite surface in dispersion was enhanced upon reduction of layer charge, which decreased its hydration, as demonstrated by Zitnan et al (2006Zitnan et al ( , 2009. However, this enhancement was not sufficient for practical utilisation of Coumarine dyes for the straightforward modification of Mt particles.…”

Section: Spectral Properties Of Montmorillonite Filmsmentioning

confidence: 97%

Fluorescence tuning of 2D montmorillonite optically active layers with beta-cyclodextrine/dye supramolecular complexes

Matejdes

Czı́merová

Janek

2015

Applied Clay Science

View full text Add to dashboard Cite

“…1,22 The majority of these studies focused on cationic dyes like Methylene Blue, 23 Acridine Orange, 24,25 Crystal Violet, 26 and Rhodamine 6G, 27 whereas there exist only comparatively few reports on clay loading with neutral dyes or zwitterionic dyes. Examples include coumarins, 28,29 pyrene derivatives, 18 aromatic hydrocarbons as well as porphyrins 30,31 and phthalocyanines. 13,14 Our interest in signal amplification strategies and the rational design of bright nanometer-sized fluorescent reporters encouraged us to systematically assess the potential of dye− nanoclay hybrid materials with the ultimate goal to derive dye structure−property relationships for particularly bright materials with emission in the visible and red spectral region.…”

Section: ■ Introductionmentioning

confidence: 99%

“…Furthermore, in order to gain a better understanding of the adsorption behavior and the local environment of guest molecules in clays and the possibility of dye–dye interactions, particularly solvatochromic dyes were employed for the probing of the polarity and acidity/proticity of the host binding sites at the clay surfaces. , The majority of these studies focused on cationic dyes like Methylene Blue, Acridine Orange, , Crystal Violet, and Rhodamine 6G, whereas there exist only comparatively few reports on clay loading with neutral dyes or zwitterionic dyes. Examples include coumarins, , pyrene derivatives, aromatic hydrocarbons as well as porphyrins , and phthalocyanines. , …”

Section: Introductionmentioning

confidence: 99%

Highly Fluorescent dye–nanoclay Hybrid Materials Made from Different Dye Classes

2016

View full text Add to dashboard Cite

Nanoclays like laponites, which are commercially avaible in large quantities for a very moderate price, provide a facile solubilization strategy for hydrophobic dyes without the need for chemical functionalization and can act as a carrier for a high number of dye molecules. This does not require reactive dyes, amplifies fluorescence signals from individual emitters due to the high number of dyes molecules per laponite disk, and renders hydrophobic emitters applicable in aqueous environments. Aiming at the rational design of bright dye-loaded nanoclays as a new class of fluorescent reporters for bioanalysis and material sciences and the identification of dye structure-property relationships, we screened a series of commercial fluorescent dyes, differing in dye class, charge, and character of the optical transitions involved, and studied the changes of their optical properties caused by clay adsorption at different dye loading concentrations. Upon the basis of our dye loading density-dependent absorption and fluorescence measurements with S2105 and Lumogen F Yellow 083, we could identify two promising dye-nanoclay hybrid materials that reveal high fluorescence quantum yields of the nanoclay-adsorbed dyes of at least 0.20 and low dye self-quenching even at high dye-loading densities of up to 50 dye molecules per laponite platelet.

show abstract

Fluorescence Dynamics of Coumarin C522 on Reduced-Charge Montmorillonite in Aqueous Dispersion

Cited by 10 publications

References 36 publications

Nile-Red–Nanoclay Hybrids: Red Emissive Optical Probes for Use in Aqueous Dispersion

Nile-Red–Nanoclay Hybrids: Red Emissive Optical Probes for Use in Aqueous Dispersion

Fluorescence tuning of 2D montmorillonite optically active layers with beta-cyclodextrine/dye supramolecular complexes

Highly Fluorescent dye–nanoclay Hybrid Materials Made from Different Dye Classes

Contact Info

Product

Resources

About