Absorption and emission characteristics of merocyanine 540 in microemulsions

Dixit, Namrata; Mackay, Raymond A.

doi:10.1021/ja00347a085

Cited by 65 publications

(34 citation statements)

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“…It is a solvatochromic dye whose absorption spectrum shifts with polarity [34,35,37]. As many amphipathic molecules, it has a strong tendency to dimerize in aqueous solutions [26]. The absorption spectrum of the dye in water has a double-banded structure (501 and 533 nm) and the extinction coefficient is concentration dependent, indicating dimerization of the dye [38].…”

Section: Discussionmentioning

confidence: 99%

Quantification of lipid bilayer effective microviscosity and fluidity effect induced by propofol

Bahri¹,

Heyne²,

Hans³

et al. 2005

Biophysical Chemistry

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Section: Discussionmentioning

confidence: 99%

Quantification of lipid bilayer effective microviscosity and fluidity effect induced by propofol

Bahri¹,

Heyne²,

Hans³

et al. 2005

Biophysical Chemistry

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“…As previously reported for MC540 in alcoholic media (Hoebeke et al, 1988;Aramendia et al, 1988), the shape of the absorption spectrum of the photoisomer is similar to that of the thermodynamically stable ground state although the absorbance is somewhat lower. The presence of two absorption maxima (490 and 530 nm) is likely to be the consequence of dye aggregation as in the case of the ground state (Dixit and Mackay, 1983). The analysis of the photoisomer decay revealed that at least two exponentials with close lifetimes are involved and that the major contribution arose from the faster one.…”

Section: Resultsmentioning

confidence: 94%

“…In contrast, little is known about MC540 photophysics in water. The only report is that of Dixit and Mackay (1983) where it is shown that MC540 molecules may form aggregates and may emit fluorescence. The present work is devoted to the investigation of 3MC540 in water: surprisingly, the triplet yield was found to be excitation wavelength dependent.…”

Section: Introductionmentioning

confidence: 99%

Triplet Yield of Merocyanine 540 in Water Is Wavelength Dependent

Seret

Hoebeke

Vorst

1990

Photochem & Photobiology

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Monomers and aggregates of Merocyanine 540 (MC540) in water are able to photoisomerize. The shape of the photoisomer absorption spectrum is very similar to that of the ground state. Triplet state of MC540 in water has been produced by energy transfer from triplet anthracene and displays a broad absorption spectrum between 600 and 700 nm. The triplet state may also be produced by direct excitation of MC540 with UV light. However, when the dye is excited by visible light, no triplet state absorbance in the red could be detected so that the triplet yield of MC540 in water seems to be excitation wavelength dependent.

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“…The fluorescence of the supernatant, representing MC540 released from the cells, was subtracted from the fluorescence of the cell suspension to obtain fluorescence data of cellbound MC540. The relative fluorescence quantum yield is defined as the quantum yield of bound MC540 divided by the quantum yield of the dye at the same concentration in aqueous solution, both measured at the emission maximum [19]. Lipid peroxidation was assayed by measuring the generation of thiobarbituric acid reactive species (TBARS) as described by Miller et al [20].…”

Section: Methodsmentioning

confidence: 99%

Effect of hydrogen peroxide on the binding of Merocyanine 540 to human erythrocytes

Lagerberg

VanSteveninck

Dubbelman

1997

CMLS, Cell. mol. life sci.

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The fluorescent dye Merocyanine 540 (MC540) is often used as a probe to monitor the molecular packing of phospholipids in the outer leaflet of biomembranes. In a previous study we showed that the increased staining of erythrocytes with a perturbed membrane structure was mainly due to an increase in the fluorescence yield of cell-bound MC540, rather than to an increase of the number of bound molecules. Erythrocytes and ghosts exposed to continuous fluxes of H2O2 exhibited pronounced lipid peroxidation. Further, red blood cells subjected to this form of oxidative stress also showed increased staining with MC540. It appeared that this was caused by a strong increase in binding of MC540, together with a slight red shift of the fluorescence emission maximum and a small increase in the fluorescence yield of bound MC540. The changed MC540 binding characteristics were not observed when lipid peroxidation was suppressed by the presence of the antioxidant BHT in the incubation medium. However, open ghosts exposed to H2O2 showed no increase of MC540 binding, excluding a direct involvement of lipid peroxidation. Measurement of fluorescence emission spectra and gel filtration studies showed that MC540 can bind to H2O2-exposed hemoglobin. Experiments with erythrocytes lysed in hypotonic medium after exposure to H2O2 revealed that peroxidation of lipids with H2O2 induced a non-specific permeabilization of the plasma membrane to MC540, thereby allowing MC540 to bind to the oxidatively denatured, more hydrophobic hemoglobin. These results indicate that conclusions about packing of phospholipids in the outer leaflet of the membrane based on increased MC540-staining should be drawn with care.

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Absorption and emission characteristics of merocyanine 540 in microemulsions

Cited by 65 publications

References 0 publications

Quantification of lipid bilayer effective microviscosity and fluidity effect induced by propofol

Quantification of lipid bilayer effective microviscosity and fluidity effect induced by propofol

Triplet Yield of Merocyanine 540 in Water Is Wavelength Dependent

Effect of hydrogen peroxide on the binding of Merocyanine 540 to human erythrocytes

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